Pro Circuit T-6 Stainless System (2022 Kawasaki KX250)

The muffler on the stock 2022 KX250 sounds a little too blown out for me in stock form (even when new). The tone of the muffler is not pleasant to the ear, so I crossed my fingers, called Pro Circuit and picked up a T-6 (stainless system) Muffler System to see if it enhances the current engine character of the KX250. Ti-6 and Ti-6 Pro systems are tough to get at the moment so we settled on a stainless system, which can last longer (more durable) than a titanium system. While I had a PC system, I thought it would be cool to give you guys a run down on a couple other mufflers that I have tried on the KX250 and compare those with the PC (see below). Here’s what I came away with… 

Immediately I weighed the stock and PC T-6 mufflers and took notice of how the Pro Circuit system cut just over 0.7 pounds off the green machine so we were starting off well. The next thing that made me happy was that the PC muffler goes on easy and literally took me 7 minutes to change out! Boom! So far so good! After installation I recruited my son to help me evaluate the system as he now has a new found love for the KX250 and a Team Green ride that didn’t exist last year. I made him write his notes down and I told him we would compare both of ours after we have tested this muffler at a few different tracks. We tested the T-6 at Glen Helen, Perris, secret dez tracks and State Fair MX just so we knew exactly what we were getting out of the PC system. 

 When you purchase your T-6 muffler it will come with a spark arrester screen already installed inside the muffler. DO NOT REMOVE THIS! This helps with back pressure and gives the KX250 the RPM response and bottom end that Aden (my son) and I both like. When we took it out the PC system lost some excitement down low and lost a little bottom end. You can however punch a small hole through the back of the screen and then reinstall it. Doing this actually helps give the PC system a little more bottom end/RPM response while still retaining that back pressure that is important for rear wheel connection. 

Ok so now that we got the “tricks” out of the way, how does this PC system compare to stock?. Normally I DO NOT get more bottom end with a PC system (versus stock) on any brand of bike, but I was surprised that I got a little extra bottom end pulling power out of the PC system. RPM response is a little softer than the stock system, but when opening up the throttle out of corners the KX250 (with the PC system) pulls harder than the stocker. Mid range is where you will feel the meat of this power. When accelerating out of the corner and shifting to third, the KX250 doesn't have that “empty” feeling that the stock muffler has at times when the track is tilled deep. The PC system keeps pulling once the KX250 is shifted into third gear and continues to pull harder into the top end. Over-rev is as good as stock and I didn’t notice any loss of over-rev when swapping the two mufflers back and forth. 

 The only real negative I have found from the PC system is I wish it would have a little more low end RPM response, like the stock system. The stock muffler has such great initial touch of throttle which can make the bike feel a little lighter when hopping over bumps or popping out of blown out berms. The PC system pulls better out of corners, but is just a smoother initial touch (AKA, low end RPM response). If you want more low end RPM response and could stand to lose some pulling power then take the screen out of the T-6. Doing this will give you more low end RPM response, but will hurt some mid range and it will not sound as good in my opinion.

Overall Aden and I are pleased with the PC system for the 2021 KX250 and I guess we shouldn’t be surprised as they do have that Kawasaki race team and all. My son surprisingly felt most of the pulling power, but didn’t feel much increase anywhere else, so not bad for a 14 year old squirrel. Hey, Mitch! If you’re reading this, good job! Chanceability that he reads this? ZERO. POINT. ZERO! 

Extra Credit: We tried a HGS and FMF system just to see what we had in the Pro Circuit T-6 Muffler System. 

HGS: The HGS has a bottom end feel similar to the Pro Circuit system but not as good as a mid range pull. The HGS system has more top end than the PC and FMF system, but it takes a little work to get there. If I was riding a sand track, I could see how someone could like this system. Great top end-over-rev. 

FMF: The FMF has more bottom end than the PC system and has slightly less mid range than the PC, yet more the than the HGS. Top End is short and over-rev has slightly less. than stock. 

Yoshimura RS-12 Full Stainless System (2022 Honda CRF250R)

The 2022 Honda CRF250R is a hot commodity and an aftermarket muffler is even hotter. With COVID-19 wreaking havoc on supply, new muffler systems have been a little slow to get released to the consumer. The Yoshimura RS-12 for the 22 CRF250R should be in stock by the time you read this so let’s compile some notes and talk about some points about the new RS-12 system, before you make a 1000.00 purchase on a aftermarket muffler shall we? 

Install:

Installing the new full system took me less than 20 minutes and the instructions were very detailed. All of the parts that came inside the box fit perfectly and it was easy enough that my 15 year old son installed it! In my opinion, Yoshimura is one of the highest quality exhaust manufacturers in the industry. I have been a part of a few R&D departments and I can tell you first hand that the quality, fit and finish of a Yoshimura exhaust is impressive. I wanted the stainless full system because it was less expensive ($909.00) but is a little heavier than the stock muffler system by just over a pound. I didn’t care about weight as much as performance so stainless is fine with me! 

On The Track:

Now to the part that everyone wants to know...Does the Yoshimura help the little red screamer? The simple answer is yes, but who likes simple answers? Not us! With the stock system, the 22 CRF250R pulled nicely bottom to mid-range, but lacked some top end and over-rev. When trying to grunt up obstacles, the engine still needs some help, but the 22 CRF250R is much better than the 21 in this department. This had Yoshimura rethink their RS-12 for 22 and came in with a spec that keeps most of that bottom end/low RPM responds but added mid range meat and top end pulling power. With the stock muffler the Honda still liked to be ridden a gear lower at times in corners (than other 250F machines), and if I didn’t, it took a bit of clutch feathering and more shifting to get the bike pulling hard again.

As soon as I fired the bike up with the new RS-12 exhaust it was clearly a bit louder, not obnoxious, but a nice, throaty sound that was deeper and less raspy than the stock muffler. I tested the stock system back to back with the Yoshimura system on the same days, so it was cool to see the places on each track where the bike really felt different. The most noticeable place the bike felt better was exiting out of corners while accelerating out of tight inside ruts. With the stock system I had to slightly slip the clutch and pay attention more to my RPM’s, all the way up the lip (If there was a jump out of a corner). When I bolted on the Yoshimura system I could leave it in second gear and just use the meat of the new found Yoshimura power to pull me up and over those types of jumps. Some areas of the track I had to be in second gear and then immediately shift into third with the stock system. With the Yoshimura system I could now be in second gear and let it pull that gear longer rather than having to shift. The Yoshimura RS-12 can also recover quicker if you’re in too high of a gear through corners. The RS-12 picks up quicker and makes the bike feel a little lighter through the mid-range. On soft berms the RS-12 allows the rider to stay on top of the soft stuff better than the stock system because of that quicker rev feel. From mid to top end is where you will notice the big difference between the RS-12 and the stock system. You’re able to pull each gear longer and with a harder feeling pull when making that shift. I would even venture to say that the mid rpm response is slightly crisper when in third gear not to mention that recovery feel in third gear through deep corners is notable right away. Bolting on the Yoshimura RS-12 full system will not make your Honda more responsive down low, but I appreciate that it didn’t complete kill that newfound low end that Honda needed for 22. The best part is that the Yoshimura muffler looks much cooler than the stock ones and sounds ten time better. 

 If you have a 2022 Honda CRF250R and feel like you’d like a bit more mid-top end power, I’d definitely look into the RS-12 stainless system. Yoshimura offers three options, the slip on mufflers ($719.00), the full stainless system ($949.00), and the full titanium system ($1259.00). Admittedly none of these are super inexpensive options, but it’s one of the few things in today’s four-stroke world that can provide a true bolt on benefit. 

Akrapovic Evolution Muffler System (2021-2022 Honda CRF450R)

I had the initial impression of the Akrapovic Evolution muffler system as I was doing a MotoConcepts/Bullfrog Spas Honda team test. I noticed that they have been running Akrapovic systems on their bikes, so I asked if I could borrow one to see how it worked. Akrapovic's Evolution line is their full titanium muffler system and includes more in the complete package than other system that I have unwrapped. The welds are beautiful and to me the quality of the complete system is second to none. Installing the Akrapovic takes a little bit of finagling, but with some patience it does line up and fit well, as long as you leave most of the bolts loose when installing. 

Once out on the track is when I realized that this Akrapovic muffler system could actually help this Honda chassis calm down just like it did to the 2020 chassis. The Evolution system lets the Honda’s engine roll on smoother at low RPM’s and that smoother feel helps the rear wheel connection as well as provides less pitching (off throttle) than the stock system. AKA MORE COMFORT!!! The Honda CRF450R now builds a smoother roll delivery and a pulling power that is longer through the mid range than the stock system. This type of character can allow you to use second gear in corners more because the second gear hit is not as abrupt or quick and that doesn't upset your technique or the chassis. The Akrapovic also allows the rider to shift later out of the corner with its increased over-rev capabilities. Pulling power up top is increased slightly as your shifting points can be altered now because of the longer pull in each gear. The mid range recovery of the Akrapovic is not as good as the stock system, but honestly that is not a bad thing. The Honda has so much power to work with that a little less “hit” as well as “recovery” actually helps me roll my corners better and allows me to be more aggressive on the Honda. I want to be able to ride this red bike and not let it ride me after 15 minutes into a moto. The Akrapovic system relaxes the engine as well off throttle. There is not nearly as much engine braking with the Evolution system and that also helps your fork from feeling harsh on small de-cel bumps.  

The pitch of the Akrapovic is ridiculously quiet when on the track and will almost give you that MXGP sound and feel. It still has that racey, crisp sound, but just not that raspy high pitch tone of the stock muffler. I was normally a map two guy with the stock muffler, but with the Akrapovic installed I am now a map one guy all day long because of the added rear wheel/friendlier connection. The only other muffler that I have tried that made a big difference on this bike was the FMF system, but this system really gives you a wider pulling power than the FMF. 

The Evolution muffler is the largest possible muffler for the space available. This allows increased sound silencing, which mitigates the impact on the natural environment while also facilitating improved flow for the exhaust gases to make their way from the combustion chamber with as few restrictions as possible. The added strength created by the design aids durability and provides enhanced resilience in the most demanding conditions. The Akrapovic mufflers have been one of the toughest mufflers that I have encountered over the past couple years when I have tested them! Akrapovic muffler packing usually outlasts others and to me just feels like quality stuff.

The Akrapovic system will save you 2 pounds over stock and will set you back a whopping $1547.00! Is the cost worth it? I wouldn't go that far, but it is one of the better muffler systems that I have tried on the 21-22 Honda CRF450R. If I was a Honda owner I would rather invest in a Vortex ECU, have it mapped, and save a few hundred bucks, because the Vortex ECU can do more to help the power character/chassis feel than that of the Akrapovic system. However, if you do have a deep pocket book and are going to get a muffler system anyway, this Akrapovic would be a great choice along with the Vortex. The combo is an amazing feeling once out on the track! It’s a beautiful system and works very well on a wide variety of terrain/tracks. 

Go to akrapovic.com to locate your nearest dealer. 

FMF Fatty/Gnarly Pipe & Powercore 2 Silencer (2022 YZ250)

The 2022 Yamaha YZ250 is a hell of a fun bike to ride. Even though I am not a huge two stroke guy, I had a great time riding it and thought it had a better engine character than the previous model. The new intake design really helps smooth the power down low and makes it broader through the mid range. There is more rear wheel connection than I remember on the 22, which makes four stroke lovers appreciate this two stroke. I had the chance to try an FMF Factory Fatty pipe as well as a Gnarly pipe with a Powercore 2 silencer and wanted to give you some feedback to see if it could be worth your while on your new 22 Yamaha YZ250.

FMF Factory Pipe/Powercore 2 Silencer:

After installing the FMF Factory Fatty Pipe and Powercore 2 there was some noticeable changes to the YZ’s power character. Bottom end had a cleaner feeling down low as the stock YZ250 does feel slightly rich on low rpm situations. As soon as you crack the throttle you will get a cleaner response, but not any added snap down low. Where you feel the Factory Fatty pipe/Powercore 2 combo is through the mid range as the YZ250 has better pulling power when shifting from second to third out of corners. I also had the feeling that the YZ250 now had a longer pulling top end/over-rev feel and could pull 2nd, 3rd and 4h gears longer down straights than the stock system could. When the track is deeply tilled the FMF system does make the YZ250 feel a little more spunky with its clean mid range rpm response so popping out of corners in a hurry is made easier. I did notice slightly less rear wheel traction with the FMF system, but I don’t think people that are looking to purchase a two stroke pipe and silencer aren’t necessarily looking for rear wheel traction. Overall, the FMF Factory Fatty pipe and Powercore 2 silencer is a nice upgrade from the stock system. Not to mention that it looks really nice with that raw pipe against that blue plastic. 

Gnarly Pipe/Powercore 2 Silencer:

If you’re looking for more bottom end hit, lugability as well as more rear wheel traction the Gnarly pipe/Powercore 2 combo is your ticket. This combo will help with bottom end rpm response and keep that clean feel that the Fatty has, but will get you more snap as well as allow you to lug the YZ250 a little more through corners. If you find yourself a gear too high at times through corners the Gnarly has better recovery than the Fatty does. As weird as it sounds this combo gave the YZ250 more rear wheel traction/feel than the stock system or Fatty/Powercore 2. I can roll the throttle on sooner with this set up and not break the rear wheel loose as easy. Mid range meat/pull is slightly better than stock, but not as good as the fatty. The down side to the Gnarly pip/Powercore 2 silencer is that it made the top end feel rich/dirty so I had to lean the clip (raise one) as well as go down one main jet size. Once I did this it helped clean it up but still didn’t pull as good on top as the Fatty did. 

If you have any questions about this test please feel free to email me at kris@keeferinctesting.com.

X-Trig ROCS Tech Triple Clamp (2022 YZ450F)

It’s hard to find aftermarket triple clamps that are better than stock these days, especially on the Yamaha YZ250/450. So much is involved in making a triple clamp that flexes enough, but also has enough rigidity to aid the machine in corners as well. With the triple clamp flex character so important to chassis handling (on all motocross bikes) sometimes it’s tough to find anyone that can make a “comfortable” set of aftermarket triple clamps. Why do you need aftermarket triple clamps? Well sometimes it’s just for looks with some riders, but there are occasions where you might want another offset to help you get more stability or a sharper turning character out of your machine. In this case I was looking for the standard offset for a 2022 KTM Yamaha YZ450F and wanted to see if installing X-Trig’s on the Yamaha hurt or helped it. I was hoping to help cornering positivity without sacrificing rigidity balance. Oh and I also purchased these myself for $850.00! 

Enter X-trig’s ROCS Tech Triple Clamps and PHDS Mounts. “ROCS” stands for “Revolutionary Opposing Clamp System”. The ROCS clamp allows for precise alignment of the fork tube with opposing clamping surface patterns, the stiffness of the steering stem is specifically tuned to the respective motorcycle model, the steering-head bearing is already mounted on the shaft tube for convenience, a special fork slot and clamping area for precise fork operation, precise clamping with special screws for low torque specs, OEM attachments can be mounted without auxiliary material, and flexibility that is adapted to the fork with anodizing in the technical factory OEM look. The difference between the ROCS “Tech” and the ROCS “Pro” is the “Tech” uses a standard offset with a pressed shaft tube. The “Pro” has two offsets you can choose from by simply adjusting the shaft tube (or steering stem). I didn't feel like the Yamaha needed an offset change as the Yamaha is predictable on straight line and corners well, so I stuck with the “Tech” clamps. 

The PHDS (Progressive Handlebar Dampening System) is a system supported by elastomers designed to absorb engine and chassis vibrations. The system also dampens the forces acting on the handlebar in a horizontal and vertical direction, maintaining steering precision. The handlebar can be adjusted in 12 different positions when the PHDS is mounted. The Yamaha doesn’t necessarily vibrate more in the handlebar area than any other 450 motocross bike, so this isn’t something I feel the Yamaha needs particularly, but if it helps, so be it.
Installation of the ROCS clamp is fairly straight forward (with the pressed shaft tube). All you need to do is grease up the steering head bearing and slide the bottom clamp up in the head tube of the frame. Super clean! Mounting up the PHDS bar mounts is a little tricky as the mounts themselves have a lot of moving parts, so make sure to read the instructions to ensure proper mounting. Technical Touch offers optional PHDS bar mount elastomers that come in soft or firm, but I chose to run the stock medium style elastomers, which seem to be just fine for motocross conditions. 

I am super picky about bar positioning, shocking I know and the Yamaha isn't the best rider triangle out there, so I went with the second mounting hole closest to me (when sitting on bike) on the triple clamp with the PHDS mounts back. This handlebar position gave me a +3mm bar position (forward from stock), which I preferred as the stock positioning is a little cramped for my 6’0 frame. The PHDS bar mount itself is +2mm higher than the stock bar mount, which I was just fine with as I am using a SX Race Pro Taper EVO handlebar on the 2022 YZ450F. Having so many positions available for the rider is definitely a huge positive for adjustability with these ROCS clamps on the Yamaha to open up the cockpit for you bigger riders (5’11 and up). If you feel like you need a higher PHDS handlebar mount, X-trig also offers spacers to go under the PHDS mounting system. You can pick from 3mm, 5mm, and 10mm spacers.

So what did the X-trig ROCS Tech Triple Clamp and PHDS handlebar mounts do on the track? My goal for this test was to dissect the anti-vibration qualities as that seems to be the easiest to feel asap. I honestly didn’t notice any less vibration/harmonics through my Pro Taper’s, but I did notice slightly less vibration on higher RPM’s which I found strange. The PHDS mounts do help flex and are a little kinder to my wrists than the stock mounts. While I was looking to get a more precise front end feel through corners, without getting added rigidity on hard pack/rough straights, that is not quite what I found. Basically I got slightly less compliance on lean angle bump absorption so the front tire didn’t exactly feel like it was digging into the dirt enough for me on faster sweepers with chop. The X-Trig ROCS Tech clamp on the Yamaha YZ450F provided enough flex if I was heading straight into bumps, but once I started leaning into braking bumps to set up for the corner, there was definitely less comfort in that area compared to stock. There was some added rigidity when leaning when bumpy and that cause the fork to feel harsher. The ROCS Tech clamp is most noticeable in a positive way when diving deep into a rut where there is a huge load put on the front end, forced by the rider. The chassis positivity through this area is much better than the stock clamps. The stock clamps has a tendency to flex too much and give the rider a wiggle once off throttle in area 1-2 of corners, (on deeply tilled tracks or soft dirt) or give the rider an unsettled (dive) when dropping into a long/deep rut (this sensation can only be felt mostly by faster or heavier riders). The X-trig ROCS Tech clamp gives the front end less wallow (firmer) and more cornering stability once inside the rut (without upsetting chassis balance). Straight line stability isn’t as good as stock as you do feel more of the track under you (front end) on hard pack west coast conditions.

I do feel like slap down landing of the PHDS mounts are more absorbing and I like that feel to my wrists. I am almost keen to try these mounts on the stock clamp to see if that works as good on my old ass wrists! The overall weight of the X-Trig clamp and PHDS mounts are heavier than stock so know that you will be gaining almost a pound of front end weight on your machine. So at the end of the day am i happy with my purchase? I would say for this bike, no I am not. I will say that I have tried X-Trig’s on a KTM with really positive results, but this confirms to me that the average rider DOES NOT need these for his Yamaha YZ450F. Does that mean all aftermarket clamps are rated under the same umbrella? Absolutely not! Not every clamp is created equal. I will try some more aftermarket clamps on this machine in the coming weeks to see if we can keep the stock bump absorption while adding to that positive front tire feel in ruts. Stay tuned! 

Akrapovic Evolution System (2021-2022 KTM 250 SX-F)

When you purchase a 2021 KTM 250 SX-F TLD version the bike comes with a slip on Akrapovic Evolution muffler. However, I know that sometimes, certain machines react better to full systems rather than slip ons, we decided to get the full Evolution system to see how it changes the KTM 250 SX-F’s engine character. 

The Akrapovic Evolution full muffler system has a similar character to the slip on version that comes with the Factory Edition, but with added bottom end roll on and mid range. If you’re expecting a ton of added RPM response (excitement) from your full system compared to your standard slip on, you will be disappointed. You simply will not be getting that much added rpm response with the Akrapovic full system. Instead of a smooth roll on that the TLD version comes with, it now has a little more pulling power in second and third gears and pulls those gears much longer.

Mid range pulling power is increased, but the muffler pitch is so quiet that you never really feel like you’re “on the gas”. The mid range pull is much more linear and longer than the standard slip on or stock muffler and being able to shift a little earlier with the full system makes it easier to ride in softer conditions. I had a hard time with the KTM 250 SX-F at softer tracks not recovering, if I shifted early out of a corner. With the full system at the same track I was able to shift into third and not have to worry about covering the clutch as much. The full system just simply gives me more “meat” in the mid range.
 Top end and over-rev is where this Akrapovic Evolution system shines. Adding top end and over-rev to the already very capable KTM 250 SX-F only makes this machine more fun to ride. Again, I can’t stress on how deceiving this system is because of it’s quiet nature. I really had to focus in and feel how quick I was going from point A to point B on the track because the pitch of the muffler never sounds “racey”. However even with its quiet note, the Akrapovic full system lets the KTM pull so much farther that it almost feels like I swapped to an aftermarket ECU. The connection to the rear wheel with the full system is unmatched and even though it may seem like it’s not very responsive, the KTM with the Akrapovic full system allows the rider to get on the gas sooner through corners. 

As described the Akrapovic badging will eventually get marked off when cleaned.

If you’re reading this and wondering why you can’t simply purchase an Akrapovic headpipe for your Akrapovic slip on, the answer is they will not mate up. The Akrapovic slip on has a smaller diameter OD, (where it meets the stock headpipe), so purchasing just the headpipe will not work. 

A couple of durability notes: 

-The Akrapovic lettering on the headpiece resonance chamber will wear off after a few washes. 

-The Akrapovic muffler stickers will burn away around the 7 hour mark. 

-The overall quality of the system and the parts inside the muffler are second to none. The muffler packing lasts longer than other aftermarket systems and the hardware it comes with is superb. 

-Is the system worth the $1200.00 price tag? Comparing it to other systems out there, I would say you’re getting what you’re paying for. A lighter, race oriented system that gives the rider better overall power throughout the rpm range. 

Acerbis K-Future Handguards

I have gone through a few hand guards over the years and have had my favorites, but recently we got to try the Acerbis K-Future Handguards for our KTM 250 SX-F test bike. The Acerbis K-Future Handguards have dual-injection covering, a lightweight, compact yet flexible flap design that can protect your brake/clutch pumps. I like that you can directly fix the K-Future Handguards to Brembo/Magura clutch/brake systems with just a bolt that is provided by Acerbis. You simply take out your OEM clutch/brake perch bolt, install the Acerbis hardware, one zip tie and boom! DONE! These guards are not a pain in the ass to install and it’s even more awesome that I can replace the stock crappy KTM XC guards with these quickly if need be.  

Acerbis offers a wide range of guards on their site, but we were looking for some handguards that could withstand some light smacking of some bushes (west coast bushes like greasewoods, manzanita, cholla) in the desert as well as deflect some roost/rocks on the motocross tracks. I like that the K-Future guards can pivot along with your clutch/brake adjustments and follows the angle in which you put them. The angle in which the guard is placed in conjunction with the lever seem to be just the right level with a couple test riders that rode with these guards. If you like to have your hand guards offset from your levers then these guards may not be the right choice for you. I would make look into the X-Force hand guards for offsetting your levers in order to get the right amount of courage for your hands. In our case the K-Future guards protected our paws flawlessly with her issues. 

The amount of coverage the K-Future hand guards provide is something I should have looked into a while ago. Although I am not a huge handguard guy, I recently broke my pinky finger and could have used them in a race at Glen Helen. Visually hand guards bother me when riding, but with these K-Future guards, I didn’t really get bothered by the wide look of them. The way the guards are shaped gives my eyes a less wide/fat feel on the bike. Ventilation has been excellent on hot summer days. There hasn’t been one complaint of hot hands during our long summer motos here in Southern California. The vents are not so big that dirt or roost can hurt the hands and I also like that I can hit a right hand inside corner hard enough and not snag my front brake on a stake or hay bale. Yes, we still have hay bales here on occasion! When we did venture out into the desert for some trail rides, we did like that the K-Future guards were sturdy enough to smack some bushes (not trees) at speed without wincing in pain because your hand just took a 60mph impact.

For $52.95 the K-Future handguards are a good investment to help prevent rocks and roost from hurting your fingers/hands. As I am typing this now, my pinky is still pissed off at me because I didn’t have these on. Three months later and it still hurts! I must be getting old because I am wearing a chest protector and handguards! Holy crap, send help!

Action And Reaction (Fork)

With every action there is a reaction right? This is no different when it comes to dirt bikes and the mechanics of each change/adjustment. Since suspension is always a hot topic with motocross machines, I thought why not give you guys some insight on what each change point/adjustment available to you on the fork, can do out on the track (good or bad). The action of one change can have reaction on the opposite end of the machine as well, not just the focused area. Here is a “fork” breakdown of action and reaction. Look for the “shock” portion of this article up soon right here on keeferinctesting.com. 

Fork:

Air Pressure: Effectively setting the air pressure in an air fork, higher or lower, is the same thing as going up or down on your spring rate. 

Action/Stiffer: Stiffening (or raising) the air pressure can allow your fork to ride higher in its stroke, can create more hold up on slap down, de-cel, etc., can make the ride attitude of the bike ride higher in the front, increase firmness in which you hit obstacles with the front end. 

Reaction/Stiffer: Going too stiff can cause harshness or a too firm feel when hitting bumps, can cause deflection when fork is light in its stroke (near the top), can cause less front wheel traction (especially on lean angle), pushing sensation through area 2 (middle) of corners, allow the bike’s ride attitude to be too front end high, effectively causing the shock to feel low in the stroke under acceleration, which can make rear end feel too firm or give rider less rear wheel traction. 

Action/Softer: Softening (or lowering) the air pressure can increase plushness, allow the fork to move further down in the stroke under load, make the action of the stroke faster, can increase front wheel traction (especially on lean angle), give a more supple feel to the hands through the bars. 

Reaction/Softer: Allow the fork too dive on de-cel, create a low front end feel that allows the rear end to kick you on braking bumps (rear shock overpowers the front end), causes too much pitching on/off throttle (teeter totter movement), oversteering through area 2 of corners, harsh feeling (firm) around the track because the fork is riding in the stiffer part of the stroke/damping, fork bottoms out more than 2-3 times per lap, can cause the shock to ride too high in the stroke and give rider harsh feeling off throttle. 

Compression: Compression damping/clickers are there for you to allow your fork’s stroke to stiffen or soften up when compressed. 

Action/Stiffer: Depending on if you’re a Showa, KYB, or WP rider will depend on how many clicks you can adjust to actually feel a difference. Showa forks are more sensitive to clicks than that of a WP or KYB fork. I would adjust one click per adjustment with a Showa fork and two clicks each adjustment with the other two brands if you want to feel a difference. Going to a stiffer compression setting on your fork can also give the rider a plusher feeling if he/she is too low in the stroke to start with. Stiffer can create better hold up in soft conditions such as deep/tilled loam, sand, mud, etc. Increasing compression can make the ride attitude of the bike ride higher in the front, as well as increase firmness in which you hit obstacles with the front end.

Reaction/Stiffer: Negative affects of going stiffer can range from deflection on/off throttle, rigidity feeling up, increased headshake on throttle, too firm of a feel when hitting bumps, harsh feeling through bars, less front end traction (especially on lean angle), pushing sensation of the front wheel in area 2 of corners, allow the bike’s ride attitude to be too front end high feeling effectively causing the shock to feel low in the stroke under acceleration, which can make rear end feel too firm or give rider less rear wheel traction.

Action/Softer: Softening the compression can increase plushness, allow the fork to move further down in the stroke under load, make the action of the stroke faster, can increase front wheel traction (especially on lean angle/more tire contact patch), give a more supple feel to the hands through the bars. 

Reaction/Softer: Allow the fork too dive on de-cel, create a low front end feel that allows the rear end to kick you on braking bumps (rear shock overpowers the front end), causes too much pitching on/off throttle (teeter totter movement), oversteering (knifing) through area 2 of corners, harsh feeling (firm) around the track because the fork is riding in the stiffer part of the stroke/damping (mid-stroke), fork bottoms out more than 2-3 times per lap, causes the shock to ride too high in the stroke and gives rider harsh feeling off throttle, unbalanced feel around track (more comfort in front end with less performance/hold up than shock).

Rebound: The rebound damping allows the fork to move faster or slower when compressed. It can also act as a type of damping force as well. 

Action/Faster: More front end traction because the fork is moving faster, which in turn is causing the front tire to get back to the ground quicker over bumps/square edges, can help straight line stability, can increase plushness through the beginning to mid stroke, can help from front end diving when jumping.   

Reaction/Faster: Can cause headshake on throttle, could make fork feel too soft on de-cel through braking bumps (diving), can allow front end to come up too high off faces of jumps (boner air), can cause pushing sensation of front tire through area 2 (middle) of corners/front tire climbing out of ruts, busy feeling front end, which can make you hold on too tight and cause arm pump.

Action/Slower: Can allow for more damping feel (firmer), slow the front end down off throttle which can give you increased front end traction in ares 2 (middle) of corners, less movement of the initial stroke/under throttle while hitting acceleration bumps, can brig front end down more off faces of jumps (less boner air).  

Reaction/Slower: Can give rider a harsher feeling on/off throttle when hitting bumps, could make fork feel too firm on de-cel through braking bumps (too high/harsh), front end diving too much (endo) off faces of jumps, can cause a ride attitude that is too low off throttle, that low feeling can give the rider less cornering stability through choppy ruts, allows the rear of the bike (shock) feel high in off throttle situations.  

Fork Height: The fork height can allow the rider to customize how much cornering ability he/she wants as well as stability by raising/dropping fork legs inside triple clamps.

Fork Height/Action: Raising the fork height can allow for increased lean angle front end traction, can give the rider a sharper cornering motorcycle, easier initial lean/tip in coming into corners, and a lower front end feel. Dropping the fork height can increase stability on throttle as well as cornering stability through area 2-3 of corners, can allow for a taller front end feel. 

Fork Height/Reaction: Raising the fork height can give a rider less stability, more oversteer (knifing) through corners, an unbalanced front to rear feel while riding, so sometimes running a lower sag setting (dropping the rear end) will help increase rear wheel traction through area 3 to exit of corners. Dropping the fork height can give a rider a slower cornering machine (side to side), a front end push through area 2 of corners, too high of a front end feel which, may force you to run a higher sag setting (raising the rear end) because the rear of the bike can feel too low under acceleration with the fork dropped in the clamps.

Dubya Edge Wheel Set

I will be straight up with you all… I am not a huge fan of $1500.00 wheel sets. Most of the time, I am a big stock wheel/hub guy, but in some cases I do need a little more security or toughness  in my wheels. I am a big believer of bringing an extra set of wheels to the track just in case you get a flat or have some sort of wheel failure. Full disclosure: The Dubya Edge Wheel set has been in my shop for more than a year and I am just now getting the information out to you guys now! Why? A couple reasons… I am normally a stock wheel set kind of rider and I am very finicky with rigidity, yet most of the time aftermarket wheel sets have given more rigidity that I wasn’t looking for. Finally, after a year or so, I got off my ass and put them on my 2021 Honda CRF450R as I have experienced some wheel problems with my Honda’s in the past. So why not test the Edge wheel set with a bike that actually could use it! 

The Dubya Edge wheel set was created for the blue collar type of rider that is looking for some added bling with durability. Each Edge wheel set centers around a forged aluminum Edge proprietary hub, which are laced to a Dubya by Excel rim, using stainless steel Dubya spokes and nickel plated steel nipples. Each wheel set is pre-assembled in Dubya USA’s Southern California facility by the same technicians who assemble all of Dubya’s top professional factory riders and teams wheel sets. Instead of using your stock wheel spacers, the Edge wheels come with their own specific spacers to each bike. I actually like when aftermarket wheels come with their own spacers as it can make your dollar stretch further! How? Well, we have a couple Yamahas in the shop that have different axle sizes (two and four stroke) so it’s nice all we need to do is swap spacers instead of getting another hub. It just makes swapping wheels more seamless. 

We have put nearly 50 hours on the wheels themselves and so far we have been pleased. The hub has been surprisingly not as rigid as I initially thought and the rim also has held up to the standard local motocross abuse. I am not over jumping landings or slamming into faces of jumps on purpose, but I feel like I am fairly hard on a bike, yet these Dubya wheels have given me zero headaches. The stainless spokes needed to be adjusted a few times after break in, but since then, they have stayed within a quarter turn of true. For $639.00 I feel like this wheel set is a great purchase for the rider who wants a fresh look on his/her bike as well as some durability that you maybe can’t find at times from your stock wheel set. I also like that the color of the hub doesn’t fade or beed out after several rides/washes. I don’t trust a lot of “inexpensive” wheel sets, but this is one that I am happy to put my hard earned money on. The weight of the complete wheel set is just north of the stock wheel set by a half a pound, but this is something that I did not feel once out on the track. 

The Dubya USA Edge wheels are available with the standard front rim size 21×1.60, while the rear wheels come in 19×1.85, 19×2.15 or 18×2.15 rim sizes. If you’re looking for some cool colors, the rims come in either black or silver, and the hub color matches the brand of machine you’re riding. The only brands that can mix and match the Dubya USA Edge hub colors are KTM (orange) and Husqvarna (blue), since they are exactly the same, but I don’t think you will be running blue on your KTM. Dubya currently doesn’t offer an Edge set up for the #RMaRMy, but hopefully you Suzuki lovers can do your battlecry loud enough, so that John and Kristen from Dubya can hear you.   

If you have any questions about this test please feel free to contact me at kris@keeferinctesting.com 

FMF 4.1 Muffler System (2021 KTM 250 SX-F)

My son and I have been going back and forth on mufflers for his KTM 250 SX-F and have went though about three until we settled on the FMF 4.1. We have tried the HGS (which was good), a Yoshimura, as well as a Pro Circuit system, but for his riding style and what he was looking for from the engine character, we decided on the FMF 4.1 system. Why? Here are some reasons why the FMF 4.1 system works well for Aden and the KTM 250 SX-F. 

First off, the FMF 4.1 system looks beautiful and is easy as pie to put on. Installation literally took 10 minutes and I like that FMF pipe springs last longer than the stock KTM pieces. Aden rides lower in the rpm and only revs his bike in the air (which he thinks helps him but it really doesn’t) so he needs some low end rpm response as well as some low end torque to help get the KTM back into the meat of the power (or “recovery”). You will get more low to mid RPM response as well as more mid range pulling power with the 4.1. Top end is increased slightly plus the over-rev is as good as stock. It is one of the few times that I was impressed with a muffler because it was actually better than stock in almost all areas. THIS IS VERY RARE! Coming out of corners the KTM 250 SX-F now has some more excitement in second gear and pulls harder than the stock system. Third gear roll on is also noticeably more reactive to your throttle hand (increased connection) and can allow for a lazier rider to have more pull in softer loam. We did pull the spark arrestor/insert out with good results and decided to leave it out for maximum throttle response and torque feel. Leaving it in will kill a little low to mid response, yet you still will get better torque feel over stock. 

The downside is that you must keep up on your muffler packing (every 10-12 engine hours) because the FMF will blow out and that could damage your expensive titanium can. Just in case you’re numbers guy, did I mention that you will lose almost two pounds with the titanium 4.1 system? If you slap on spring forks on your KTM, you will be gaining almost three pounds. You can get most of that weight gain with the spring fork back down with a 4.1 Titanium FMF Muffler system.

Things to look out for? I can burn a lot of pants on the headpipe of the FMF system. The magabomb portion of the headpipe can burn your pant just above the boot when sticking your leg out in deep ruts. This has happened on only a couple different brands of gear (FXR, FLY) with the FMF headpipe installed. Overall we are happy with this system for the way Aden likes to ride and will be refurbishing his mufflers every 10-12 hours in order to keep the most performance possible. Hopefully FMF will have these back in stock in the near future so be on the lookout over on their website that gets updated weekly on what is in stock. Damn you Covid!

Ride Engineering 23.5mm Offset Split Triple Clamps (2021 Honda CRF450R)

I have been looking for some added stability and comfort from my 2021 Honda CRF450R test machine since I got it and although my suspension setting has evolved/improved over time, I still need some compliancy from this machine. I have been working with Adrian over at Ride Engineering on some split triple clamps for over a year now and we finally have come up with a feel that I think is better than stock. I have yet to test any other competitors clamps back to back as Ride Engineering is one of only a couple aftermarket companies that are making different offset clamps. I have tried a 24mm offset on the 2020 Honda CRF450R and really liked how it made the Honda have a “slower” feeling chassis. Slower in this sense was a good thing for the Honda as it calmed the chassis down on rough tracks for me. So in order to get some added chassis compliance, I tested Ride Engineering’s 23.5 offset clamp for the new generation Honda CRF450R and here is what I took away from the test. 

Stats:

The Ride Eng. 2021 CRF450R/RX Split Triple clamps are available in Red or Black, come in two offsets and cost $649.90. Custom colors available for $100 additional if you want a custom set. The Ride clamps save you 10oz. in weight and come in 22mm offset or the new 23.5mm option. A Showa steering damper option is available without drilling your frame so no need to stress on that. The bar position on 22mm offset is 8mm forward of stem hole allowing a 5mm or 11mm bar position, with Ride Engineering’s one piece bar mount ($104.95), also available in 7/8” version. The bar position on 23.5mm is 9.5mm forward of stem hole allowing a 6.5mm or 12.5mm bar position with Ride Eng.’s one piece bar mount (I preferred mine set at 12.5mm). Note: Stock OEM bar mounts will fit and affect the numbers above by 2mm (3mm or 13mm on 22s & 4.5mm & 14.5mm on 23.5s).   

How Do The Ride Engineering 23.5’s Affect The 2021 Honda CRF450R?: 

I will be quite honest with you… We went through a couple of versions before I felt that it was good enough to sell to the public. The first couple versions didn’t have the compliancy I needed nor did we have a different offset yet that I preferred. The first thing that I noticed with the Ride Engineering 23.5mm offset clamps is that it took away some of the dreaded vibration that the 2021 CRF450R has through the bars. Once I pulled out onto the track and started to accelerate I could feel less harmonics/vibration coming through the Pro Taper bars. What I wanted from the 2021 Honda CRF450R (as well as from the Ride clamps) was a calmer entrance in/through corners, less oversteer, better straight line stability, and increase in front tire tracking. 

I got all of this with the new 23.5 Ride Engineering setting! With my fork set at 2-3mm in the clamps as well as a rear shock sag measurement of 105mm I had a CRF450R that was less harsh feeling through my hands. Now the Honda didn’t quite give that sting through my arms on flat landings and gave the front end an increased flex feeling. Diving into ruts that start to get hooked, didn’t give me the front end knifing (oversteer) that I experienced at times with a 22mm offset. We call this cornering stability in the testing world and the new 23.5mm setting gave me increased cornering stability. Let’s face it, we all love the way the Honda corners, but sometimes it can corner too good and cause some in consistencies in your cornering technique. This 23.5mm offset Ride clamp still gives you that easy to lean front steering feel of the Honda, but improves area 2-3 (mid-exit) in corners.
Straight line comfort has also been improved thanks to losing some rigidity up near the head tube area. When testing the Honda CRF450R I never could have suspected that the OEM clamp was some of the problem when it came to getting a harsh feeling. Hitting square edge and braking bumps with the 23.5 Ride clamps gave me less harshness and improved my fork feel. The fork now seemed to move more in the stroke and had a slightly softer feel to it, which was nice, but also forced me to adjust my fork setting somewhat. With the Ride 23.5 clamps, I had to stiffen up my fork setting one click and slow the fork don one click also. Doing this gave me a better front tire feel when leaning on throttle. I ended up getting better front tire tracking (when stiffening/slowing the fork) when cutting across rough sections of the track. Once I figured that I could go stiffer with my setting it actually brought up the performance/comfort feel of the Honda CRF450R. The stock torque specs of 15 ft. lbs. on the top clamp and 12 ft. lbs. on the bottom clamp is recommended, but if you end up purchasing a raw/silver clamp, you can go to a 14/11 setting. 

So what’s the negatives? Honestly for a vet rider like myself, there aren’t too many… I do know that this isn’t a cure all for the rigidity issues of the CRF450R, but it does help a noticeable amount. When I let another Honda rider/owner try my test bike with the clamp, he immediately thought his OEM clamp was too stiff feeling. The negative for me is that you may have to adjust your suspension (to compensate for the softer feeling clamp) a little after installation, but to me having to do some minor clicker adjustments isn’t too much to ask for added comfort. Plus, y’all are Honda owners. You’re used to tinkering on your bikes right? I know I am when I ride this machine. This Ride Engineering 23.5mm offset split clamp will eliminate some of the tinkering you’re doing at the tracks most days by 40%, so you can ride more and be a test rider less. 

If you do end up getting the red colorway, please try to cover your clamps up with a towel or something when your bike is siting in the pits. The sun will fade the anodizing over time, so bring an EZ-UP or a towel to cover up your investment. These clamps are sexy looking so take care of them! If you’re a C rider worried about if you will lose that cornering ability of your Honda, have no fear, adding these clamps to your machine will not negatively affect how easy the Honda will lay over in corners. In fact, it might help you improve your corners as the CRF450R will setting into the corners better with this 23.5 offset. 

There is a discount code available if you decide that this may be something you're interested in. KT20 will save you 20% off your order over at ride-engineering.com. If you have any questions or concerns  about this test please feel free to email me at kris@keeferinctesting.com.   

Yoshimura RS-12 Stainless Muffler System (2021 Kawasaki KX450)

The stock 2021 Kawasaki KX450 is pretty damn good machine, but that muffler looks atrocious right? We called up on Yoshimura to see if we can get a more attractive aftermarket muffler system that is actually better than the stock system. I will say that the stock KX450 muffler system works pretty damn well, but as always we are constantly looking to try aftermarket pieces because as we all know, you are only as good as what you try! 

The Yoshimura RS-12 Stainless System is made in the USA, is rubber mounted to the subframe, its asymmetrical shaped muffler allows maximum capacity and incorporates a resonance chamber for managing sound and increasing usable power, the unique shape also provides more clearance for tire and brake caliper, has a new patent pending Precision Taper Fit (PTF) insert ring that can make it easy for the consumer to install and remove sound inserts as well as spark arresters, comes with a carbon fiber end cap and can be fully rebuilt with repacking kits that Yoshimura sells. If you’re looking to lose a little weight with the muffler, you will have to look towards the titanium system. The stainless system weighs in at 9.12 pounds, which is slightly heavier than the stock muffler, that comes in at 9.1 pounds. We aren’t necessarily looking to lose weight in this instance, as power, sound and reliability are more important to us with this unit. 

The stock muffler system is pretty damn good, as the power character of the KX450 is long and linear, but the stock KX450’s engine character could use a little more pulling power and more mid rpm response. Installing the Yosh RS-12 was painless enough and we really appreciated the rubber sub-frame mount that the Yosh muffler comes with. Having a rubber mounted rear muffler mount helps avoid the sub frame tab breaking off due to solid mounting. Once on the RS-12 is visually still big looking, but the RS-12’s exhaust note is so much better to the ears that we lost focus on how big the RS-12 looks. Out on the track we noticed how much easier the KX was to corners because there was less on/off feel from the engine on low RPM because the Yosh builds power a little more smoothly between 5000-7000 RPM. The RS-12 is less touchy to the riders throttle hand and to me that helped calm the chassis down in area 2-3 of corners. You will not get as much throttle response from the RS-12 as you do a FMF or a stock system, but to me this is a good thing. The mid range pulling power is what you will come to love from the Yosh system. Pulling power out of corners is noticeably better than stock and the rider can shift into third earlier without having to use the clutch in order to get the engine to recover (back into the meat of the power). Rear wheel traction was also an improvement on hard pack tracks as the KX450 had a better second gear flat corner sensation to the rear wheel than the stock system. Top end feels as good as stock with maybe a little more over-rev, so if you’re a little lazy the RS-12 can help you slightly in that area as well. 

If you’re looking for a more explosive rpm response from your KX450, the RS-12 may not be the muffler you want to go with, but if you want added pulling power out of corners as well as more rear wheel traction with a better exhaust note, then this Yoshimura RS-12 stainless system for your KX450 is a great buy. The benefit about stainless steel is that the overall construction of the muffler will last longer than titanium. Most of my practice bikes over time had stainless systems on it for the sake of durability. Slip fit titanium joints just don’t last as long as stainless. For $850.00, the RS-12 system is a good buy with quality construction that you expect from Yoshimura.  

ARC RC-8 Clutch Assembly With Aluminum Black Smooth Lever

I will admit that I am usually a stock perch/lever or a Works Connection Elite Perch/Lever kind of rider and although I have tried many different perch/lever set ups those are the two that I normally gravitate towards or back to. I have tested a lot of combos and have come to the conclusion that it’s tougher to make a better than OEM lever feel, perch and engagement feel. Now enter the ARC RC-8 Clutch Assembly With Aluminum Black Smooth Lever and I have found another perch/lever combo that I am genuinely happy with. Other perch/lever set ups that I have tried have either screwed up clutch engagement points with their odd ratios (and messed my corners up) or the lever is simply doesn’t have the right shape for my size large hands (lever shape is a key component to feeling comfortable with your rider triangle). Designing/making a perch/clutch lever is harder than most people think obviously. If you don’t get the lever ratio correct, you will have a clutch feel that is on/off or an engagement that is too grabby or slow feeling. Not easy. 

This ARC Billet Aluminum CNC-Machined lever assembly is the one that a lot of top teams run. If you haven’t met ARC Bob then you are really missing out. You might have heard me talk about him on some Racer X videos because the guy is a mad scientist of levers/perches. He will not rest until he’s created massive headaches for consumers due to the fact that he gives us so many damn options!  The features of this perch/lever combo start with the ARC aluminum smooth lever with a 27mm ratio, which I am a fan of. I am not a foldable lever kind of guy because I like a solid feel to my finger when I am pulling in the clutch. It just gives me a more positive feel and this lever seems to give me just that. Not to mention that the lever shape is one of only two shapes in the aftermarket lever business that I can get along with. There is a nylon sleeve that contacts the handlebar that allows for rotation in a crash, which is nice when you have a tendency to tip over in corners from time to time.

The cable 1/8 turn quick adjust has a large diameter rubber wheel that is easy to reach for/adjust on the line or in the air. yes, even if you’re a novice rider, you will be able to adjust it in the air! One of the other highlights is the "external pivot". The pivot bolt screws into the lever and the bolt rotates in the perch on replaceable bushings. Whaaaat! This eliminates almost all up and down play in the lever and gives me the positive engagement feel that I look for. In the world of tighter tolerances, this is what you want from a big four stroke. When you have horsepower, you could possibly get more vibration and that can radiate towards the ends of your levers. When you have a tighter tolerance in your levers, you get less vibration feel and more positivity on each end of your bike. It may not seem like much, but it’s the little things that make a difference when it comes to “feeling factory”.  It’s also nice that the clutch pull gets a little easier on the bike that I installed the ARC perch/lever on (2021 YZ450F).

At a cost of $205.00 for the complete perch/lever it’s a sizable investment, but with the quality of Bob’s work at ARC, I am happy to pay for something that I know I am going to love as well as last! ARC gives you a lot of ratio and lever options, so go visit the mad scientist of levers website at www.arclevers.com. 

Works Connection Pro Launch Device

Works Connection had an older start device that used the old school spring and plunger design, but now have since gone to a magnetic locking system on the Pro Launch device. This has been in circulation for a few years now and is one of the most no fuss systems on the market. It’s so popular that Factory HRC Honda and Star Racing Yamaha is using this exact same system. Because of its lever-style mechanism and chamfered engagement point, the Pro Launch easily goes over the receiver on the way down and catches on the way up. So simple. that even Mrs. Keefer can manage to catch the engagement point relatively easy. It took her some time, but now she understand that you must hold the lever mechanism up once the ring passes by the mechanism. If you want to take out the mechanic/girlfriend/wife out of the equation you can simply do it yourself. I can either hit the front brake and lift up on the mechanism with my boot or stand in front of the bike and reach down with my right hand to lock the device! Boom! Tall riders can simply pull down the front fender (while pushing with their chest on the crossbar pad) when sitting in the saddle.

Works Connection provides an aluminum template with pre-drilled holes, plus three different paper templates in the shape of each bike brand’s fork guard to align the aluminum template at 90mm, 100mm and 110mm. Once you choose the location of the device, tape the metal template and use the supplied drill bit to make the mounting hole. I usually run my Pro Launch devices at the 110 mm setting on 450s and 100mm on 250s. I even use the Pro Launch on metal grate starts as well. The durability of the PL is second to none and I have not  experienced one failure yet on a Pro Launch device that I’ve used for two full race seasons (over 20 races, that’s over 80 motos).

Here is a little Q&A that Works Connection has put together, just in case you have more questions. If you are looking to purchase any Works Connection products you can use the code Keefer20 to save 20% off any WC product. Oh and if you’re on a WP Cone Valve fork WC offers a special ring for those forks, FYI! 

Q. What’s included with each Pro Launch? 

A. Every Pro Launch includes a fork ring, trigger assembly, drill guide, countersink and 

Any supplementary hardware required for specific models is included at no additional cost.

 Q. Why isn’t the Pro Launch made to be universal with one kit fitting all bikes?

A. We feel there are too many variables to produce a reliable ‘One size’ fits all Pro

Launch. 

Does a ‘one size’ pair of shoes sound like a good fit for everyone?

Our design team tailors each fork ring, trigger assembly and instruction templates for the specific year/make/model to ensure an exact fit that yields consistent, dependable, long term performance.

 Q. Why doesn’t the Pro Launch use a split/hinged fork ring?

A. While you might save a few minutes of installation time with a hinged fork ring, 

our design provides a lighter, yet stronger and more reliable fork ring that eliminates the potential failure of a split/hinged ring.

 Q. Who designed and who manufactures the Pro Launch?

A. Our in-house design team is responsible for the patented design and manufacturing, 

along with packaging, is done right here in Nor-Cal, USA!

 Q. What purpose do the fork guard straps serve and do they cost extra?

A. Some brands (e.g. Honda) use a softer fork guard material and the fork 

straps provide the necessary reinforcement. And for those applications the fork 

guard straps are included at no additional charge.

 Q. Can you set the Pro Launch by yourself?

A. Yes. While sitting on the bike, lean over the bars and pull up on the trigger with your 

right hand. Then grasp the front wheel with your left hand and pull the forks down far 

enough so the trigger and fork ring mate.

 Q. How does the trigger operate?

A. You simply lift the trigger while depressing the forks and the trigger and fork ring 

self-latch and mate smoothly. Once you get to the first turn and apply the front brake 

the trigger releases from the fork ring and retracts via strong magnets to its resting 

position. The resting position of the trigger makes it impervious to a rock strike 

accidentally engaging the mechanism.

 Q. Does the Pro Launch add weight to a bike?

A. The Pro Launch weighs in at 50 grams (1.76 ounces) making it the lightest on the 

market.

 Q. How long does it take to install the Pro Launch?

A. Typical installation time is about 30-40 minutes.

 Q. How do I know where to mount the trigger and fork ring?

A. Our step-by-step instructions include a bike specific paper template for the trigger

location and photographs to illustrate the fork ring location. These instructions are

included with every Pro Launch and are available to download from our website.

Q. Can you service the Pro Launch.

A. We assemble the Pro Launch onsite so we have every replacement item available.

 Q. Who uses Pro Launch?

A. Anyone looking for the advantage in getting off the start gate first. That includes 

amateur riders on minis all the way up to Factory Pro Teams.

Q. Where can I get a replacement paper template?

A. On our website navigate to your Make/Model/Year, select the Pro Launch page and

it’s available to download by clicking on ‘Instructions’.

 Q. What if my bike isn’t listed?

A. E-mail info@worksconnection and we’ll get you an answer.

 Q. Will the Pro Launch work with aftermarket fork guards.

A. The Pro Launch is designed for use on the stock, OEM fork guards.

The Makings Of A Great WP Pro Component Settings On The KTM 450 SX-F (With REP Suspension)

Let me preface this article with how much I like to ride the KTM 450 SX-F. But… Yes, of course there is always a “but”, right? I like a lot of things about the KTM 450 SX-F, but the stock suspension isn’t one of them. The AER fork is a slight headache for me as it’s stiff as hell when new, then once broke in, moves more in the stroke, yet still gives a harsh mid stroke feel on braking bumps. Not as much as in year’s past, but it still isn’t a spring feel. Raising the air pressure only makes the harshness worse and decreasing air pressure allows the fork to ride too low in the stroke for my taste. I am a front end steering rider and that means that I really like a spring fork feel. Now, I have tried some other companies spring conversions and although better than the AER fork with front end traction/feel, I just wasn’t sold on the performance it gave me on rough tracks. After doing some of these tests, I then resorted to a WP Cone Valve fork. Now I am not going to sit here and tell you that slapping on a set of WP Pro Components is the answer to your front end problems, as I did have to go through several setting changes in order to get a feel that I personally liked. I thought why not walk you through some of the process to create settings as well as tell you about the latest one I have on our 2021 KTM 450 SX-F test machine. 

You know who helped me get to this blend of KTM comfort and performance promise land that I am in? Mark Johnson at REP Suspension. I am a serious pain in the ass when it comes to KTM suspension, probably because I love that damn Yamaha KYB/SSS fork so much (yes, I know there are KYB conversions and we are going to test one soon, don’t yell at me). Although Mark made my WP Pro Components better than my stock stuff the first time he did it, I felt like I wanted more comfort on rough tracks. I complained to Mark that my rear end always felt too low under acceleration and the front end still had a firm feel on slap down hits through my handlebars. I complained. He listened. That is what great suspension tuners do. They listen to the customer. There are several companies like this out there and REP is one of those companies. Mark emailed me one night about a setting he came up with, that he thought I might rather enjoy. I honestly thought what I had was decent, but as one old test rider once told me, “you’re only as good as what you try right” and I am in the business to try and relay that back to you all right? So I immediately got excited about another suspension test that could really be “THE ONE”! 

I met Mark at GH one Thursday and we literally stayed there all day. This is nothing new, but as a guy who has been doing this 20 or so years, I still love it! I wanted to make sure that I left GH near dark and when the sun decided to set behind the hills of Glen Helen, I wanted to make sure that I had comfort along with performance, before I gathered my things and left. This is the only way I can sit here and type to you all and say if it’s better or not. When you move from a stock WP AER fork to a WP Pro Component set up you will immediately feel a heavier turn in, yet will receive more front end traction. It’s a give and take and I will gladly take a heavier steer in (area 1 of the corner) for added traction. I don’t have near as much of a problem with the rear of the bike, but the stock shock, once hot, fades away into oblivion and gives no real damping character at the end of a longer/rough Moto. I wanted consistency, comfort and traction. Is that so much to ask from a bike? The Kawasaki gives it to me. The Yamaha gives it to me. I want the KTM to give to me as well with WP components on it! 

As usual I make sure that each test is a blind test. I make damn sure I know nothing about what Mark and the REP crew do to each setting and that I am going strictly off of feel when riding. I make sure I hit the same lines on the track through out the day for consistency and that ensures proper feedback to the REP crew (as well as you the reader). When all was said and done, what REP gave me was the best setting I have ever felt from any KTM set of suspension I have tried. Oh and I have tried a lot. Is it the best suspension that I have ever met period? No, but it was the best KTM stuff I have tried, hands down. I was starting to consider that the WP Pro Components were just built for performance and not comfort, but Mark and the guys proved to me otherwise.

 The WP fork with the REP setting not only had hold up, but had comfort as well. Most of the time when you go to an A-Kit style fork, you will lose comfort and gain performance, but both of those categories went up equally for me. RARE! This has only happened twice in my time of testing! Using a 4.8 N/mm spring rate along with the parts listed below gave me great lean angle traction (off or on throttle). The downside to my previous CV fork setting was that if I loaded the front tire on lean (under throttle) the fork deflected and felt harsh. The new updated setting felt more supple initially and progressively had more damping feel as the fork went down. There was no unexpected stiff shelfs in the travel as the fork moved and in return, that gives the rider better feel to the front wheel/tire. AKA more tire contact patch! Boom! Gone is the harsh slap down feel to my hands and that increased my ability to be more confident in how hard I can push into/through jumps because I know that if I wanted to overjump a section (on purpose or maybe by mistake) I could do it without an issue. 

The WP Pro Component shock has always been a struggle for me to set up. I always felt like my rear end was too low and when I managed to get the rear end up, it was god awful coming out of corners (harsh and wasn’t fun on my back). Although I gained consistent damping feel over a longer Moto with the Pro Component shock the comfort was difficult to find at times. To help this I ran REP’s knuckle without the longer rods, along with a sag setting of 98mm. I wanted to change the curve of the linkage ratio to help acceleration comfort, but try to keep that rear end up under throttle. This did get me slightly more comfort, but felt like it pushed on the front end too much once transitioning off the throttle. Mark suggested that I try a 1mm longer shock shaft and that really changed the character of this bike. Once I had the chance to ride with that, it altered my outlook on how the KTM’s ride attitude could handle rougher style tracks. The rear end stayed up higher in the stroke and for my 5’11 front end steering frame, this was a game changer. The KTM became more balanced on throttle and allowed me to accelerate harder/sooner out of choppy corners. I now could get my sag numbers back to normal range (103-105mm), which left me with a balanced feeling coming into corners (off throttle). Having this 1mm longer shock shaft also allowed me to run REP’s longer pull rods, which increased rear wheel traction and took some bite/harshness out of any initial braking bump hit. 

Now on to the question that I will get asked after this is published… Keefer, I just spent 11K on my KTM and now you are saying to purchase 5K on suspension  as well as put another 800.00 into those Pro Components? Holy shit! Yeah, I know, right? However, it’s crazy how many people actually do this. So to cater to those people as well as to others, I will also be doing a stock re-valve story just like this one coming in the next few weeks. So hold tight! Not everyone has the money for Pro Components and I am not blind to that fact. I really wanted to get this article up because I had my doubts about these WP Pro Components at times and get tons of emails about them. Mark and the REP crew worked their asses off to make me happy and it took me a while to get there, but hopefully with all of my testing that I have done, as well as REP’s work, you all will benefit from a one and done setting! 

Below are the parts that REP incorporated into my WP Pro Components and what each part’s purpose really is: 

  Fork:

1. Cone Spring Perch System $349.99

Gives more bottoming resistance/progression allowing for a softer more plush setting to be utilized for better top of the stroke feel without losing bottoming. (The concept comes from KYB which I have played with a lot).

2. Low Speed Valves $120.00

Allows us to valve the flow of the needle and is fully tunable to each rider. Riders typically comment less front dip/more controlled front under braking.

3. 13 Degree cones $160.00

WP only makes 3 degree options 15, 11 and 8. Mark makes 13 as well for MX/Off-Road and 8 for SX. This helps bridge the gap between the degrees to get a specific damping the rider is looking for.

4. Low Friction O-Ring Kit $11.99

Lower cartridge friction compared to the standard o-rings that come in the fork.

Shock:

1. Trax LSV $250

Similar to the fork LSV, it gives REP another shim stack to play with, that normally is not in the shock. The shim stack controls the needle flow and is fully tunable. (This is the part that I felt gave firmness without taking away comfort). It also majorly decreases hysteresis, or pressure differentials, in the shock, which results in a more consistent feel and performance in the shock. 

2. Shock Spring Thrust Bearing $62.99

Springs naturally want to turn as they are compressed which causes binding. The bearing is fitted on top of the spring to allow it to turn and can be put on without the damper being disassembled.

3. RCU Spacer $21.99

REP has spacers made that go on both sides of the shim stack that are surfaced ground to be more flat than production. The spacer makes for a more consistent and predictable build as far as dyno and rider feel is concerned.

4. 1mm Longer Shock Setup $112.99

Helps balance of the bike for most riders, but also gains comfort as it puts the linkage into a softer part of the stroke.

Chassis:

1. REP MW1 Knuckle $299.99

Price jumped from up from the last write up I did because they now build them with OEM Bearings and seals.

2. 149mm Pull Rod $219.00

It’s longer compared to the standard 148.2mm for the flatter leverage curve Mark was looking for, also built with OEM bearings and seals.

Pro Circuit Linkage (2021 Kawasaki KX250)

The new Pro Circuit linkage system for the 2021 KX250 and 2019-2021 KX450 gives the KX’s handling performance an entirely different feel. I did this review on a 2021 KX250 because my son Aden was only 125 pounds and needed something plusher for his style of riding. Although I liked the stock KYB suspension, I felt that it was a little empty (soft feeling) on the end stroke. The OEM linkage system for the newer KX models tends to be a little harsh at the beginning of the stroke and gets softer as the rear wheel goes deeper into the stroke. With Aden being lighter, he had problems with the rear end being harsh on small bump absorption and I had problems with the rear end being too soft at the end stroke (or high speed compression situations). With the new Pro Circuit linkage system, it gives the linkage ratio curve what we both need. The Pro Circuit KX250/KX450 linkage system gives the shock a plusher feel at the beginning of its stroke and then stiffens up as the rear wheel goes deeper into its travel. This adjustment could mean that it lessens the need for stiffer high-speed valving, which can cause the rear to feel harsh and deflective. When talking to Pro Circuit, a considerable amount of research and testing for this new linkage system has resulted in a more true-to-weight spring rate, in order to reach the ultimate sweet spot in handling for your new KX250/KX450. 

I wanted to test this linkage for Aden and I on the 2021 KX250 with stock valving as well as a re-valved set of suspension to see what this linkage system can give the rider in feel. With the stock setting and the PC linkage I immediately felt it was too soft for my liking out of corners (the rear end felt too low in the stroke at 103mm of sag), but I found out that Pro Circuit recommends a spring rate increase of 0.2 kg/mm so I wen from the stock 54 N/mm spring to a 56 N/mm with much better results. Now the rear end stayed up higher in the stroke on acceleration and felt plusher on small bump absorption. The stiffer spring and the linkage combined also gave me the end stroke feel that I was looking for. I am the type of rider that DOES NOT mind bottoming out a couple times a lap around the track, but it just can’t feel like I am hitting a ton of bricks when doing so. The PC linkage coupled with the spring rate change still allowed me to use all of the suspension but didn’t give me that harsh bottomed out feel. 

With Aden on the KX250 with the PC linkage, it was even more noticeable change for him because he could leave the stock spring on and the rear of the bike immediately got plusher feeling on small chop. He also mentioned that he could get on the gas sooner because he felt like the PC linkage gave him more rear wheel traction. Normally, being that Aden is only 125 pounds we usually have to go to a softer shock spring, but with the PC linkage requiring a stiffer spring rate, this ultimately balanced the bike out for a 125 pound B level type of rider.  

When tested with a fully re-valved set of Pro Circuit suspension the linkage only gave the rider more of a balanced feel with the sag at 103mm. Riding more aggressive was made slightly easier with the PC linkage as I could get on the gas sooner out of corners (under heavy choppy conditions) because the rear end seemed to stay straighter as well as had more rear wheel traction. For $445.00 this mod is a little expensive for my taste, but it does actually help with comfort and performance on the 2021 KX250. If you’re a lighter rider, this linkage could save you from a spring change and if you’re an aggressive rider, that is slightly heavier, it can help you from getting too low in the stroke under heavy loads without a re-valve. 

If there was one sentence that described this linkage it would be: “Ultimately, this new PC linkage creates a plusher feel while increasing rear wheel traction”. 

If you have any questions about this pinkeye please feel free to email me at kris@keeferinctesting.com 

DR.D Stainless Full Muffler System

By: Michael Allen And Kris Keefer

It’s no secret that Doug Dubach knows Yamahas. That being said, after years of testing for Yamaha Doug started Dubach Racing Development where he builds finely tuned exhaust systems for other major motocross models. However, this isn’t one of those “other” motorcycles and we wanted to take that atrocious sounding stock muffler and try something we haven’t tried.  I met Doug through Kris and have had the privilege of hearing some old testing stories, listening to him give Kris shit, giving me the basic inner workings of exhausts and testing in general explained to me. I really look up to Doug and Kris’s testing abilities both, so when they sent me a DR.D system to try on the 2021 YZ 250F, I was excited and nervous at the same time. Excited because if anyone knows how to make a Yamaha work well its Doug. Nervous because I knew the exhaust wasn’t the only thing being evaluated; Kris always expects me to go into any test with no pre conceived notions about the product and he’s always evaluating my ability to test which is a bit nerve racking.

It’s no secret that the Yamaha YZ 250F has a damn good production engine. When the bike was redesigned in 2019, the power characteristics of the engine slightly changed from making the majority of its power lower in the RPM range, to slightly shifting the peak power up in the RPM range giving the bike a lighter, free revving feeling. While this more playful feeling is fun to use, there was still a part of me that missed the low-end grunt of the previous engine character. After Randy Richardson gave the bike a proper break-in at the Dubya USA World Vet Nationals, the stock muffler packing was extremely blown out, there was seemingly no packing left in the can. I love doing back to back testing because the difference in performance (good or bad) of a product will be far more obvious if the comparison is made the same day. So when at Glen Helen racing the Swap Moto Series I decided to race the first moto with the blown out stock muffler, and the second moto with the DR. D system. 

Although some people may think that since the exhaust wraps around the engine it must be a pain to change it was very straight forward. There was only one step that I found I needed help with to make the process easier, which involved my wife, her butt and me asking for her to sit on it….. With the stock system removed, I simply needed my wife to sit on the bike so that the shock would compress and move back enough in order to get the head pipe between the frame, shock and engine. One other tip is to tighten the two exhaust stud bolts before installing the muffler because leaving the muffler off allows for more room for a wrench. Aside from that step, leave all the bolts finger tight until all the parts are installed, so that there is a little wiggle room. 

After racing moto one I’m sure most of the spectators ears were pleased when I rolled up for the second moto with a fresh exhaust. The first thing I noticed was the change in the exhaust note, gone was the raspy clapped out tone that bellowed from the rear end of the 2021 machine. That raspyness had been replaced by a more throaty sound that obviously had more backpressure and sounded crisp. As the man in overalls ran back to the doghouse to drop the gate I focused solely on my technique and to my surprise when the gate fell I instantly felt far more connectivity from my throttle hand to the rear wheel. I got a great jump, and stayed right with the KTM 350 that was next to me until about half way through third gear. It doesn’t matter what exhaust you have, nothing is going to make up for 100ccs, not to mention all the 450 machines in my class. In addition to the improved connectivity, the power with the new system has been smoothed out. Don’t let that be confused with mellowed out; in fact the DR.D system has noticeably more mid to top end over stock, yet also gave me a little more low end that I wanted back from the Yamaha. Instead of just making noise and spinning, the bike is now able to put that power to the ground and drive forward. The DR.D system not only helps get the power to the ground, it helps clean up some of the FI setting near the low end range on slower corners. I felt like the NS-4 muffler brought some added mid range meat to third gear and allowed me to make my shifting points later than the stock system did. 

To be honest, most manufacturers in 2021 make very good stock exhaust systems that don’t leave much room for improvement. When it comes to performance gains over the blown out stock system, this DR.D full system surprised the hell out of me and I think an exhaust shootout may be in order soon. With a price tag of $659.95 this stainless and aluminum system is a great deal when compared to the price of other manufacturers and is still lighter than stock by over a pound. It may not be the lightest thing on the market, but let’s get real, you and I don’t need the weight loss on our machines. Maybe I need to lose a few before my machine. Once again Doug proved that during all those years helping develop Yamaha’s YZ’s he was taking notes on what works and what doesn’t. If you have any questions about the 2021 YZ 250F DR.D exhaust system, reach out to me at Michael@keeferinctesting.com.

You can get a DR.D muffler system over at www.dubachracing.com.

Keefer’s Notes: 

 I concur on what Michael has written and would like to add that to me the bottom end character is improved with the DR.D on. The bottom to mid RPM response is not only better but to me gives the rider more control around the track. Michael mentioned being more connected to the rear wheel and that right there is what I noticed the most. 

On My Own Dime (High Roller Tie Downs)

If you’ve ridden dirt bikes for any amount of time, I’d be willing to bet you own or have owned a certain item that you’ve guarded with your life. While some of you may be thinking about a bike you loved, comfortable boots, or that rad custom painted helmet you had personalized. While all those may have sentimental value, I’m talking about something that you’re far more territorial over…. You’re favorite pair of tie downs. No, not the ones you tie your buddy’s bike down with, or the pair that you give to the neighbor when he borrows your truck to get a new refrigerator (why doesn’t he have a truck anyway?). I’m referring to the one and only pair that you use on your current bike, and have more than likely been used on the last few bikes you have owned. They may be old and look a little ragged, hell if you’re like me you have other brand-new ones that stay hung up in the garage, but that doesn’t matter to you, because your favorite tie downs aren’t worn out, they’re worn in. 

My feelings toward tie downs started at a young-ish age, probably around the time my dad started having my brother and I load up the truck before heading to the desert for the weekend. I remember my dad getting irritated with my brother and if we used his favorite tie downs on our bikes, in the back of the same damn truck! I didn’t get it! Turning 16 only made it worse because I was given the freedom to load up my shitty Mazda pickup and head out to the trails with friends. It also gave me the freedom to use whatever tie downs that were hanging in the garage. I’m sure you can see where this is going in that I would constantly use my dad’s favorite pair of red Ancra tie downs. It eventually got to the point where my dad said “thanks for destroying my favorite tie downs, they’re yours now, I bought a new pair which have my name on them, and will be kept in the safe!” (he wasn’t kidding). After those wore out It took a few years until I had a favorite pair of my own, but one Christmas my employer gave me a gift that I would guard with my life for the next 10 years; a set of black High Roller Stay Lock (cam lock) tie downs.

Admittedly the name of the company is pretty lame, and the logo looks like a spin-off of a 1998 LBZ add, but that doesn’t change the fact that they sell a great tie down. Although technically they weren’t bought on my own dime, I did later buy a set to give to my dad as a sort of apology for waging psychological tie down warfare on him throughout my teenage years. The high roller tie downs aren’t anything fancy, nor do they have wazoo features that sometimes complicate the basic functions of a tie down. For starters, I like the material that’s used; although narrower than most current day straps, they use a thicker material that seems more resistant to tearing or fraying than the wider thinner material most new straps use. The top end of the tie down uses a traditional S-hook, but also has a built-in soft strap and since it’s narrow it doesn’t need a lot of real estate on the bars if the soft strap is used. 

The lower part of the tie down uses a carabiner which is nice because its super annoying when your tie down unhooks from the bed, while you’re trying to load your bike and you have to bend over to re attach it. That being said, I would like to see a 360° swivel on the carabiner side, so the strap would never get twisted.  Like I said, I have literally used these for 10 years without any major malfunctions. The only things that aren’t perfect are the S-hooks where the rubber coating has worn through. Since these tie downs as a whole are still in great shape, I’ll continue to use them as long as they work properly. So do yourself a favor, stop stealing your dad’s tie downs and get yourself a favorite pair of straps that last! If you have any questions about these tie downs feel free to reach out to me at Michael@keeferinctesting.com.

http://highrollerproducts.com/products/tie-downs/standard-cam-lock-tie-downs/

On My Own Dime: My Favorite MX Tires

To keep up with these ongoing “On My Own Dime” articles I thought it would be informative to write about a few of my favorite tires. I don’t use the same tires year round, because quite frankly some conditions/tracks suite different tires better. For example, I raced with a MX3S/33 combo at Loretta’s and then raced with the Pirelli MX32 mid-soft’s at the World Vet’s at Glen Helen. 

I don’t always get free tires, so when I have to go purchase tires for Aden and my own personal bikes, these are the tires that I purchase. These are strictly performance based tires and are not meant to be the most durable tire out on the market. I normally am looking for performance out of my tires and not as much longevity, but I do want it to last more than a couple weekends of racing. Just know this… It is tough to weave performance as well as durability in a tire. You need to know what type of rider/consumer you are. Are you looking for the most traction out of your rubber? Or are you the type of rider that doesn’t need all the traction in the world and is just fine with a tire that last longer with a harder carcass. Below are my top picks of tires when looking to go racing.  

Pirelli MX 32 Mid-Soft Front/Rear:

Pirelli may not be the most popular tire in the AMA Supercross/Motocross paddock, but one look around the MXGP circuit and you will see more Pirelli tires than any other brand. I tested the Pirelli MX32 MId-Soft back in early 2018, but since then, the MX32 Mid-Soft tires are said to have an improved spec and I have been circulating through them regularly o my test bikes. While I don’t have much information on what was improved or why (maybe a vendor change), I did get confirmation that all of the old MX32 Mid-Soft spec tires have been out of circulation for a while. This was a concern to me as I thought some may still be floating around, but I was reassured that if a consumer purchases any Pirelli MX32 Mid-Soft tires, you will in fact be getting the updated versions. Pirelli also noted that they have dropped their pricing down on all their motocross tires $5.00-$15.00. 

Once out on the track I quickly found out that one of the first things that impressed me the most was that the Pirelli Scorpion MX32 Mid Soft’s carcass gives the rider a blend of comfort and control on choppy/square edge terrain. I have more time on Dunlops than any other brand of tire around these Southern California test track, so I am very familiar on what these test bikes feel like when they get rough. When the track does get rougher, the Pirelli MX 32 Mid-Soft rear tire (120/80-19) gives more cushion than the Dunlop I have been riding on lately. The Pirelli carcass acts like another piece of your bike’s suspension and can really help a rigid feeling chassis become slightly better on choppy terrain. It impressed me so much that I tried it on a 2020-2021 Honda CRF450R and it gave me less of a harsh feel. To me that was impressive on this machine, because the Honda needs more comfort and the MX32’s carcass did just that.

Pirelli also offers a 120/90-19 size rear tire as well that was even better on square edge cushion feel, but the 120/90-19 also puts more weight on the front end of the machine, which increases front-end steering, but negatively affects the ride height. If you do decide to go with the 120/90-19 and feel like your rear end is too high after installation, I do recommend dropping your sag 1-2mm to prevent a high feeling rear end on de-cel (stink bug). 

The Pirelli MX32 Mid-Soft rear tire offers great traction on soft/intermediate terrain through ruts and coming out of soft corners. The MX32 works well under lean angle and that lean angle traction is one of Pirelli’s rear tire strong suits, as the rider is able to get on the throttle sooner (while leaning) without washing out. The contact patch that I get with a Pirelli at Glen Helen is unmatched. I feel like my lean angle is more controlled and that sudden line changes are easier with the Pirelli. When riding you want the largest “feeling” contact patchiest you can find from a tire and Pirelli has done this well with the MX 32 Mid-Soft. 

Not only do you have a more controlled lean angle, but you are also able to start your lean sooner (compared to a MX33). Braking predictability gives the rider confidence to pivot and throttle out of flat corners without much hesitation. If you’re a predominately front end steering rider the Scorpion MX32 rear tire will provide you with less sliding ability and let you steer with the front tire more than the rear. If you're a rear end steering rider that likes to drift the back end around, this tire may not suit you as much as a Dunlop MX33. The only complaint I had is when the track surface was on the harder side, I could feel the side of the tire carcass roll when accelerating from flat corners. This gives me a pushing or loose feeling rear end that caused me to be less aggressive with my throttle hand. To combat some of this it’s very important to run the correct air pressure (between 14-14.5 psi) for the Pirelli’s softer style carcass. I noticed that when the Pirelli tire gets half worn, the performance isn't as good as the Dunlop if you don't pay attention to the tire pressure. When the tire gets worn, going to 14.5-15 psi helps the structure of the carcass stay firmer on its sidewall when under lean angle. 

I ran 14 psi on a half worn rear Pirelli and it felt very “washy” or vague so going up to 14.5 psi helped this roll sensation. Remember that just because the actual knobby might not be worn down that doesn’t mean the integrity of the caracass isn’t worn. Chunking wasn't an issue with the set of Pirelli’s I had, as I got well over 10 hours on a rear tire. You will also have to understand that Southern California conditions are much harder than east coast conditions, so lifespan would most likely be better in softer east coast based dirt.  

I am a picky son of a bitch when it comes to front tires! The Pirelli MX32 front tire is great for front-end feel and lean angle traction especially in heavy dirt. The softer the dirt the more responsive this front tire is. I prefer a tire that really digs into the dirt and lets you carve underneath blown out berms or ruts (happens a lot here in Southern California). The Scorpion MX32 Mid-Soft front tire actually makes the steering feel heavy at times because the tire is at maximum grip under initial lean in corners. Like I mentioned above, the MX32 is tailor made for a front wheel steering rider and can be leaned into corners earlier than you would come to expect. It took me a couple rides to fully trust this tire, but it has treated me well once I began trust it more. The only other front tire that has as much front end lean angle traction is a Hoosier MX25. This Pirelli front tire does suffer from predictability when the track is freshly watered while broken in/slick on top (think 1PM at your local track). The MX32 would give the front end a vague/push feel as the bike would have a tendency to slide unexpectedly through flat corners. Again, adjusting the air pressure can remedy some of this, so going up to 14.5 psi helps the tire not to roll so much. 

To me this is a pure soft natured front tire and if the conditions are soft to loamy this tire works great, but if the track gets hard pack, you will get some uncertainty when pushing the front tire’s limits with 13.5 psi. The wear of the MX32 front tire is adequate and unlike most soft terrain tires, the Pirelli will NOT chunk from what I experienced. I typically get 9-11 hours on a MX32 front tire before I start to see some of the performance life start to dissipate. This is a performance based tire and should be purchased knowing this. 14 psi is a good baseline for this tire, but be sure to check the pressure after a couple motos. Tire pressure will rise with heat so make sure to have a good tire pressure gauge handy in the tool box. 

The updated Pirelli Scorpion MX32 Mid Soft is one of my favorite sets of tires to put on for Southern California tracks. The Pirelli tires will require more attention during the course of the day with your tire pressure gauge, but if you stay on top of the air pressure, you will be rewarded with a tire that rivals spec tire cushion feel.

Dunlop MX3S Front Tire: 

The MX3S directional front tire is great for front-end feel and lean angle traction, especially over the older MX33 front tire in all conditions. The MX3S front tire actually makes the steering feel “heavy” at times because the tire is at maximum grip under initial lean in corners. It can be somewhat grabby if you're not used to it and can cause some oversteer, but once used to the lean angle feel the MX3S becomes magical in soft to loamy conditions. The MX3S is tailor made for a front wheel steering rider and can be leaned into corners earlier than most other tires very easily. The only other front tire that has as much, if not more front end lean angle traction is a Pirelli MX32 mid-soft. I did have a problem with the MX3S when the track had just been freshly watered and was slick on top (think of the second moto at a Glen Helen-type track). This would give the front end a vague feel (un-predictable) as the bike would have a tendency to push the front-end through flat corners (the MX53 is better in these types of conditions). The wear of the MX3S front tire is not as friendly in hard pack terrain as you can feel the side knobs roll on the hard pack surfaces. The vague/pushing sensation is common once on hard pack so you may want to stick with more of an intermediate to hard terrain tire if your local track has a hard base. Again, just like a performance tire, the side knobs can chunk off rather quickly if you’re riding on intermediate terrain often. I typically get 7-10 hours on a MX3S front tire before I start to see chunking of the side knobs. This is a performance based tire and should be looked at accordingly.

Bridgestone M59 Front Tire:

The Bridgestone M59 tire has been in production for quite sometime, but for some weird reason I must have missed it while it was in circulation. I have tested the Battlecross tires, but never even knew about the M59 until Aaron Clout (Luke Clout’s brother spoke about it). Installing the Bridgestone M59 was the easiest tire I have literally ever put on. It has a soft carcass and the bead went into the rim nicely without any fuss. Once on the track, I knew I had to experiment with air pressure because I could feel the side of the M59 roll when pushing heavy into ruts (similar to the Pirelli). I started out with 13.5 psi, but finally settled on 14.5 psi as a setting that I would recommend when riding with this tire on a 450. The 450 comes with more weight and that means more roll of this soft sidewall when you’re pushing into corners. If you want to sacrifice some of that carcass cushion on square edge you could go up to 15 psi and get some added control on lean angle. The M59 wasn’t quite as good as the Pirelli on lean, but it did mimic the MX32’s comfort if there was some chop inside of ruts. I could feel more cushion through the front end and that gave my 43 year old hands a welcome sigh of relief. 

Once I decided that 14 psi was the happy medium, I still felt the lean angle traction that I got wasn’t quite as good as the Pirelli MX32 Mid Soft. I could set up for ruts or berms on terrain that varied from loamy to semi hard pack without getting a push or vague feel, similar to the Pirelli, but I could still feel the sidewall’s inconsistency with the Bridgestone when I tried to pivot on flat corners. With the weight of the 450 and the aggressive nature of my front end steering style, the Bridgestone just wasn’t a fan of being leaned over with nothing to bank off of. The overall straight line bump absorption of this front tire wasn’t quite as good as a Pirelli MX32 Mid Soft, but was better than a Dunlop MX3S. It almost felt like the side wall had a different softer flex character and the middle of the M59’s tire was made of some harder/different type of rubber compound. The Bridgestone did suffer from some slip in corners if it was freshly watered, as I couldn’t quite be as aggressive in that area like I could with the Dunlop MX3S. 

What’s odd to me is when I tested the same tire on a 250F, I got a completely different feel. The front end could be loaded and pivoted without getting a push or a vague feel. The straight line bump absorption was about the same as on the 450, but the lean angle traction was much better. I think this has something directly due to the M59’s carcass and how much of a load it can handle on lean angle. I don’t know what Bridgestone’s target was when making this front tire, but to me this M59 is tailor made for 14 psi on a 250F or smaller machine and maybe 14.5 on a heavier 450. I rode just as aggressive on the 250F as I did on the 450 and it had a consistent lean angle feel. I also feel like this could be a great off-road tire, especially if you ride a ton of rocks. The carcass feeling of the M59 could be a welcome feeling in extreme off-road conditions.

What About The Dunlop MX33 Rear? 

Yes, I do like the Dunlop MX33 rear tire way more than I do the 33 front, so when I go to a 3S front, I usually match it up with a 33 rear. The 33 rear is heavier than the Pirelli MX32 mid-soft and the carcass isn’t quite as comfortable as the 32, but the Dunlop MX33 rear does give you a solid/non-roll type of feel when under lean while accelerating. I also like that the 33 rear feels like it has more traction than the Pirelli when worn down. I run the 33 rear at 12.5 psi because the carcass is stiffer and that seems to get me the best forward bite. I normally get around 10-12 hours of life from this tire around Southern California, depending on track conditions.

Ride Engineering Split Triple Clamps (KTM/Husqvarna)

The stock KTM/Husqvarna clamps are too stiff for me! What about you? Well, if you’re here reading this, chances are they might be too rigid for you as well!  It’s odd because most other manufacturers OEM clamps are on the soft side, but the Austrians had something more rigid in mind when making these stock clamps. So in search of other options besides an X-Trig ROCS or a KTM Factory Edition clamp, I went out and tried Ride Engineering’s new split clamp. When Ride Engineering set out to build the KTM clamps, they’ve been designed with four goals in mind: 1) Optimize body position: (Bar position 3mm back from stock). Ride Engineering also offers optional offset for their bar mounts providing 4 bar positions as measured from the stem hole: 6mm forward, 9mm forward, 15mm forward & 18mm forward (using stock bar mounts your positions are either 7mm or 17mm forward); 2) Flex: this new split design made from 2024 aluminum is said to provide better comfort; 3) Improve the handling with a new gull wing design; 4) Place the upper pinch bolts in the front and allows for different aftermarket handguard mounts. Each set comes with a frame mounted hour meter relocation bracket so that you can retain your OEM hour meter. So how did they perform on the track? We break it down for you here. 

The stock KTM triple clamps are stiff natured and can make your orange bike feel rigid/harsh. My goal for this test was to find less front end vibration through the bars, more front end comfort, as well as try to get a more precise front end feel through corners, without getting added rigidity on hard pack/rough straights. Basically get a more compliant KTM 450 SX-F, but that is sometimes tough to do right? The good news is that this is exactly what I found with the Ride Engineering Split Clamps. The Ride Engineering clamp on the KTM 450 SX-F provided enough flex on small bumps, which gave me less of a stiff feel through the bars, yet was also stiff enough to give me a positive front wheel lean angle through flat corners. The Ride Engineering clamp is most noticeable when diving deep into a rut where there is a huge load put on the front end, forced by the rider. The chassis positivity through this area is much better than the stock clamps. The stock clamps have a tendency to give the rider a rigid feel when weighting the front end (although slightly more positive feeling), deflection on de-cel bumps and vibration that is not very friendly. The Ride Engineering clamp gives the front end more tire contact patch feel because it allows the front end to absorb more of what the track is offering the rider. Going firmer on the triple clamp can give a rider more positivity at times, when leaning into a corner, but in this case, I felt like I could get into a corner much easier with the Ride clamps. Straight line stability is improved because of the bump absorption character of the Ride clamp and vibration is also down which gives the bike a tighter, less clapped out feel. Also do yourself a favor and get rid of those stock Neken handlebars. Buy some Pro Taper EVO bars and thank me later!

Compared to a factory KTM clamp (that comes on the Factory Edition) the Ride Engineering clamp does have a little more flex to it than the KTM FE clamp. The two share the same split design, but offer different flex characters on the track. The KTM FE clamp does have a slightly firmer feel, which does help area 2 of corners when pushing your front tire/front end hard while banking off of ruts. The KTM FE clamp does give a little more positivity in that area, but in all other areas of the track the Ride Engineering split clamp just has more comfort.  I tried the Ride Engineering Split Clamps with the stock mounts and the rider triangle of the bar mount position on the clamp wasn’t an issue for my 6’0 frame. I also have tried the Ride Engineering bar mounts, so if you’re taller and looking for more room, you might want to look into a set of the two piece bar mounts from Ride as well.

A lot of back to back testing went down against the KTM Factory Edition clamps in order to figure out how much flex was too much or too little.

Ride Engineering offers two offsets (22mm and 20.5mm), comes in four colors (black, orange, silver, LE blue) and redesigned with a 90mm span to accept the stock bar mounts and mounting hardware. The $689.90 price tag is also not as steep as some of the other clamps in its class and to me Ride Engineering is one of the few aftermarket chassis part companies that actually test their own products. To have an owner that rides his own parts, then makes an educated decision on if it’s better than stock, is pretty damn cool. You can check the Ride Engineering Split Clamps out at ride-engineering.com. 

If you have any questions about these clamps, or any others for that matter, or maybe want a discount code, hit me up at kris@keeferinctesting.com.