Pirelli MX32 Mid-Soft Re-Visit

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, so I grabbed a couple to test for a few weeks. While I don’t have much information on what was improved or why, 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. They even have a “MX Extra” tire that has a price reduction of $50.00 a set.

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 am usually on Dunlops 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 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 MX33/53. 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 more less aggressive with my throttle hand. To combat some of this it’s very important to run the correct air pressure (between 13.5-14.5 psi) for the Pirelli’s softer style carcass. I noticed that when the Pirelli tire gets half worn, the performance isn't as good 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 13.5 on a half worn rear Pirelli and it felt very “washy” or vague so going up to 14 psi helped this roll sensation. 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 dramatically be better in softer east coast based dirt.  

Attention! 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 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 superb and unlike most soft terrain tires, the Pirelli will NOT chunk. I typically get 10-12 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. Look for a small tire shootout soon as we will take the top MX tires and put them to the test under a 10 hour evaluation soon!

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

Hinson Nine Plate And Rekluse Torque Drive Clutch Comparison

I originally wanted to do a Hinson versus Rekluse clutch test for the 2019 Honda CRF450R, but after going back and forth for a few weeks (testing these parts), I decided that both of these mods are such an improvement over the stock clutch system, that there shouldn't be a “winner”. Each clutch has a specific character/feel on the track, but both are equally as impressive and much better than the stock system. Since we had to purchase our own 2019 Honda CRF450R test bike this year, I wanted to really try/test quality upgrades, that this bike absolutely “needed”, since we would be having to sell this unit at the end of the year. The 2019 CRF450R “needed” a clutch upgrade and so this evaluation process was born. I let my resident mechanic/blue collar test guy Matt Sirevaag install and ride with each clutch system initially and then I tested each to get my impression. This article is based on what we thought collectively, but if you want to hear even more background/feedback about these parts, check out the Rocky Mountain ATV/MC Keefer Tested Podcast that will be up very shortly. -KK

 For years Hinson has been one of the go to clutch manufacturers for factory motocross and off-road race teams. In the last few years Rekluse has been making a name for itself as they are now on a ton of race teams in any given paddock as well. So when it was time to install a clutch in our 2019 Honda CRF450R test bike, it only seemed right to ring up Hinson and Rekluse to see what they had to offer for a bike that needed help in this department. Hinson sent us their complete nine plate clutch kit (part # HC989-1901 ) that adds two extra friction plates (to a total of nine), while the stock Honda CRF450R uses seven friction plates. The Hinson complete clutch kit comes with a new clutch basket, inner hub, pressure plate, fibers, steels, clutch springs and let’s not forget the icing on the cake, a billet proof clutch cover. This is a complete kit that replaces all of your stock clutch components. 

Rekluse sent us their Core Manual Torq-Drive clutch kit (part # RMS-7101002). This kit goes a couple steps further using twelve friction plates. Yes, you read that right twelve plates! The Rekluse Torque Drive Kit comes with inner clutch hub, Torq-Drive friction plates, thin steels plates, pressure plate, core clutch springs, spring screws with screw sleeves, basket sleeves, new tab washer, and a beautiful Rekluse clutch cover.

When it comes to the 2019 CRF450R there are a couple items that can be addressed to improve the clutch. It has been well known that Honda has not exactly led the 450cc class in clutch life and/or in the clutch lever pull department. These have been weak points on the Honda CRF450R for quite sometime and usually the bike gets ranked down in shootouts because of it. Honda has made progress from their old four spring clutch as the new CRF450’s have gone back to a six spring clutch. The stock 2019 CRF450R clutch has a very narrow window of engagement and is tough to really get a linear engagement/progressive actuation when attacking the track. This makes it very hard to modulate the power in corners as the clutch makes the power similar to a light switch that has an on or off type of feel. I am sure most of you Honda guys can relate as our email inbox has seen a flood of Honda clutch questions. The clutch pull takes He-Man type strength and can expedite arm pump in a moto, which sucks huge for us blue collar riders! With a narrow window of clutch engagement and a very hard clutch pull it really makes it difficult to manage the power (of the Honda), especially late in the moto as fatigue starts to set in. The stock Honda clutch also tends to fade as the moto’s get longer and if you're a clutch dragger like Keefer is, things can get ugly (or hot) in a hurry. This leads us to clutch life; I am not even close to what you call a clutch abuser (like Keefer), but I have always taken pride in the life I can get out of a stock clutch on other machines. With this Honda CRF450R I even showed signs of wear and slightly burnt clutch plates at less than twenty hours. This was a problem that needed to be addressed. 

Besides riding these dirt bikes, I love working in the garage and wrenching on them. When the Hinson package arrived I told the wife I would be eating dinner in the shop and I began to tear into the 2019 CRF450R’s clutch. Just be forewarned that this Hinson system is a more in-depth install then just changing out clutch fibers and steels. There are some special tools needed to help with install of the clutch basket. Besides your basic hand tools you will need a clutch hub holding tool to remove and Install the new clutch hub. Also needed is a drill or grinder to remove the primary drive gear from the stock hub, so that you can re-install it onto the new Hinson billet hub. Hinson provides great instructions with pictures, which are very helpful for you novice mechanics out there (cough, cough, Keefer). Lastly don’t forget to use your OEM Owners Manual to provide you with the correct torque specs. Hinson also states adding 300cc more oil than stock, so 1300cc without changing an oil filter and 1350cc with oil filter replacement is your new levels with the Hinson Kit.

The first test of the Hinson clutch system was during the Dubya USA Vet Nationals at Glen Helen. Right off the bat I noticed that the clutch pull was slightly easier, which made me happy right away. The second positive aspect of the Hinson clutch that I noticed was that the engagement of the clutch was not nearly as narrow (or on/off) as the stock clutch. I feel this was the best part about the Hinson set up because it really helped open up my corners. I now had a clutch that I could easily modulate the power of the Honda’s engine character without shutting off the throttle. Most times with the stocker I would have an issue with the front tire jumping out of ruts or wheeling right out of a corner because I had trouble with the on/off engagement feel. However now I found myself rolling through corners with more speed and confidence knowing that I was hooking up better. The Hinson gives the sensation of added rear wheel traction and a more connected feel to the track. I didn’t notice any clutch slippage or jutter while abusing the clutch during motos and Keefer even mentioned that he could ride/slip the clutch (during his 30 minute motos) without the clutch fading.

The Rekluse Torque Drive clutch install is easier and at the same time harder to install than the Hinson. Why? Let us explain… It’s easier in a sense because you are using your stock outer clutch basket, which means there is no need for any grinders. It’s slightly more difficult because there are a lot more moving parts like the basket sleeves, which will test your patience, while installing the fibers and steels. Having said that the other important part to pay attention to is the Rekluse Torque Drive starts and ends with a steel plate, not a fiber. Another difference from most clutch kits is that Rekluse provides (in the kit) three different clutch springs to help tailor the clutch feel/delivery to the rider. Silver giving you the easiest clutch pull, gold, and then red being most aggressive with the hardest clutch pull/bottom end hit/delivery. You can run three silver and three gold or three gold and three red to really help get the clutch feel/power delivery that you prefer. I decided to go with three silver and three gold springs in hopes to help clutch pull feeling at the lever. Just note that the stiffer the clutch spring the harder it is on your transmission under heavy load (acceleration).

As I rode to an undisclosed location (Keefer’s Test Track) with the Rekluse Torque Drive I immediately noticed a much better lever feel than stock and a slightly lighter pull than the Hinson. As I made my way around Keefer’s new test track or I should say turn track, I noticed that the Rekluse has a wider window of engagement than the stock clutch, yet very close to what the Hinson had to offer as well. This makes it a lot easier to modulate the power of the Honda just like I mentioned above. You can really slip the clutch and feed the power better to the rear wheel. This gave me a new found confidence as I was able to cover the clutch and keep the Hondas front tire from lifting out of corners (similar to the Hinson). If anyone knows Kris, you know that you’re always on the clock when you’re riding, which meant thirty minute moto’s to test the Rekluse’s durability. As it neared the end of each moto (which we did over the course of several weeks) the feel at the lever stayed consistent and never seemed to fade on either Kris or I very much at all. Messing with the lever play while riding was minimal and Keefer even mentioned that he barely had to adjust the free play during his sand motos. As with the Hinson, the Rekluse clutch definitely got the power to the ground and gave both of us a little more snap (bottom end response) out of corners. The Rekluse got the power to the rear wheel better than the stock unit and nearly as good as the Hinson. The only difference we both felt was that the Rekluse had a little more bite (or pop/excitement) out of corners than the Hinson. The Hinson had slightly less bottom end hit than the Rekluse, but had slightly better rear wheel traction. The Rekluse made the Honda feel more exciting and playful out of corners without sacrificing traction. Both clutch kits provided much better power delivery/traction than the stock system and have lasted much longer as well. Another positive attribute of the Rekluse Torque Drive is that it actually improved the recovery time of the engine when I found myself in the wrong gear (mostly third gear in tight corners). With just a flick of the clutch the Honda’s engine was right back in the RPM it was supposed to be in.

This was a very educational test for me as I have never tested or used an aftermarket clutch in any of my bikes. Keefer thought it would be a great way for both of us to feel the differences between two companies that know a thing or two about clutches. The Hinson and/or Rekluse Torque Drive clutch systems are just what the Honda needs. They both improved performance as well as reliability, which to me is the most important piece to this test. I am a blue collar type of guy that works to put food on the table for my family, not pay for unwanted parts/bling for my dirt bike.

Hinson’s nine plate clutch kit retails for $1,184.99 and is not exactly what you call inexpensive, but to us, this Hinson Nine Plate set up could pay for itself if you’re hard on clutches like Keefer is. The Rekluse Core Manual Torq Drive retails for $899.00, but since you re-use your stock outer clutch basket, we can see why this costs less (than the Hinson). If I was to go purchase a clutch for my personal Honda, which this one kind of became, I would choose either one of these because they both fixed my two major gripes with the stock 2019 CRF450R clutch. Either one is a great choice, it’s just a matter of how much money is in the ol’ bank account. -Matt Sirevaag

If you have any questions or concerns about either of these products feel free to email kris@keeferinctesting.com and he can hopefully guide you into the right purchasing direction.

Dunlop MX33 First Impression

I have been through many tire tests in my day and I am aware of how much work goes into bringing a new tire design to market. Dunlop introduced their new MX33 yesterday at Zaca Station and I had the chance to test the MX3S and the new MX33 back to back. I wanted to see first hand if there were any performance advantages to the new MX33, compared to the 3S that I run on a lot on my test bikes. Now this isn't a durability review (we will do that at a later time), but this test is simply to give you some initial information before you may want to purchase a set of these come Monday when they arrive in North American dealers. Before we get to the findings on the track, let’s give you some information on the tire directly from Dunlop themselves: 

Multiple Block Distribution

In addition to creating an aggressive look, new Multiple Block Distribution technology increases the number of knobs on the shoulders and center of the tires, and also varies the height and angles of the knobs within the tread pattern. This translates to more biting edges and more traction, creating superior grip and increased handling performance.’

Block-In-A-Block Technology

After the great success of Dunlop’s patented Block-In-A-Block technology on the MX3S rear tire, Dunlop has improved this technology by altering the shape of the interior block. This new diamond-shaped block is larger, adding more surface area and two additional angles to improve traction.

Dunlop has also added Block-In-A-Block technology to the front tire for the first time, creating a new industry standard for handling and grip.

Advanced Apex Design

Not only does the Geomax MX33 look remarkably different than its predecessor, but the MX33 also has many new components under the tread. The new construction of the front and rear tire features a taller, thinner apex. Known as Advanced Apex Design, the same sidewall material used in the MX3S is now distributed in a slimmer, but taller apex. Without adding weight, this technology delivers superior shock absorption, uniform rigidity in the sidewall, and a smoother ride and firmer feel. (Applies to 18”, 19” and 21” sizes.)

Carcass Tension Control System

In this new design, Dunlop optimizes the distribution of tension of the components so the tire absorbs more shock, but flexes when necessary to smooth out ride characteristics, which allows the bike to track in a straighter line.

All-New Compound

The MX33 also incorporates a new rubber compound with a higher molecular weight polymer to improve durability and a carbon micro-particle to increase grip.

On The Track (Rear Tire 120/80-19):

Now for those of you asking, you will be able to get the MX3S for a little while longer, but just know that the MX33 is replacing the MX3S. 

Zaca Station’s soil is a mix of loose sand on top with a hard slippery base underneath. It's one of those tracks that looks like you can just hold it wide open and run it in deep, but in reality you have to be cautious about throttle delivery on lean angle at times or Zaca can bite you real quick (trust me, it’s bit me a time or two). The first positive that stood out to me was the MX33 rear tire’s ability to grip on lean angle. Usually I am a very sensitive front end feeling rider, but the MX33 rear tire was so much better than the 3S on lean angle, under acceleration, that it was easy for me to dissect rather quickly. Rolling out of corners while under throttle the MX33 bites and doesn't slide as much as the 3S when the the soil is slippery/wet. I was able to get on the throttle sooner out of slippery corners with the MX33 versus the 3S because of the positive connected feeling that I got from the 33. The MX33 rear tire also has a firmer feeling carcass than the 3S on square edge, which gave me slightly less comfort through choppy ruts and acceleration bumps. This was a very subtle feeling and some of you may or may not be sensitive to this, but this is something that I felt towards the end of our test day. Tire cushion is important when it comes to suspension feel and the 33 doesn't have as much plushness as the 3S does. Straight line traction was better on the MX33 as there is less side to side movement from the rear end under acceleration. Braking is something most do not talk about when comparing tires, but it’s a very important aspect when designing a tire for the public. The MX33 doesn't have as much ability as the 3S to drift (or slide) when brake sliding or pivoting around a corner. The 3S slides slightly better when on the rear brake and the rider is able to pivot the machine more quickly than the MX33. “Now is that a good thing or a bad thing Keefer”? The answer lies in your riding style…If you’re a rear end steering guy you may want that drifting/sliding ability in your rear tire tread design/compound, but if you’re a front end steering guy like me, then having the rear tire not slide as much is more up my alley. 

On The Track (Front Tire 80/100-21): 

I am super picky when it comes to front tires and noticed a few things from the new MX33 that differs from the MX3S. The MX33 has more lean angle bite (off-throttle) when starting your lean for corners. As soon as you get off the throttle to enter a rut or berm, you will notice the tire pulls down the front end more while biting the ground (very grabby). This may take some time for you all to get used to, but I like the fact that it doesn’t have that vague initial feeling like the 3S. Once the 3S gets into the corners its side knobs work well in soft-intermediate terrain, but I have always had a problem with that quick sudden “turn-in” with the 3S. The MX33 front tire lets you cut down from a blown out berm or make sudden line choices (with your front-end) easier due to some extra lean angle grip. Where I felt the MX33 could be lacking is on-throttle maneuverability. When finishing your corner and you start to roll the throttle on, the front MX33 has a slight “Hunt And Peck” feel to it. “What is hunt and peck Keefer”? “Hunt And Peck” to me is when the front tire has a slight wandering sensation and doesn't feel like the knobbies are dug into the terrafirma. I want to clarify that this feeling was only felt right out of a corner while under throttle. The MX3S never really feels like it has that “Hunt And Peck” feel to it under acceleration. Braking traction feel has improved on the MX33 over the 3S, as the tire doesn't slide as much as the MX3S does when the track is freshly watered or greasy on top. This is a nice feature because the MX3S front tire sometimes was a handful when tracks received some water in the middle of the day. The MX33 front tire is also more consistent when scrubbing up faces of jumps and will not slide away from you as easy as the 3S. When the track is nice and broke in and all of that good dirt has been pushed away, the MX33 was noticeably better than the 3S. The MX33 was more consistent in all “off-throttle” situations and provided more bite, especially on lean angle when the track gets hard pack.  

Conclusion/Sizing:  

The Dunlop MX33 is available in 10,12,14,16,17,18,19 and 21 inch sizing. A new 90/100-19 sizing is offered by Dunlop in the MX33 as well. My first impression of the MX33 was a good one, but I really want to dissect these tires some more at different tracks next week. It should be noted that the MX33 worked best at 13PSI instead of the normal 13.5 PSI of the MX3S. I will also be testing the durability of the 33, to see if the carcass is better (than the 3S), like Dunlop says it is when it comes to knob chunking. The MX33 should be available at your local dealer by Monday May 14th.