2021 Kawasaki KX450 First Impression

2021 isn’t a ground breaking year for Kawasaki’s KX450, but it did get a couple key changes that make a difference on the track. Kawasaki put more of its R&D focus on the KX250 in 2021 with several changes. I mean the 2020 KX450 was on the podium in almost every media shootout, so a couple refinements could go a long way. I spun some laps on a tight, ruttier type of track rather than the high speed chop of GH and Cahuilla, where most of the other media outlets tested, just so I could abuse the clutch as well as see how the new handlebar made me feel in tight ruts. Here are some thoughts about the refined version of the 2021 Kawasaki KX450.

2021 Change Points: 

New Cone Disk Spring Clutch (On The Track):

Last year I had a problem with the Nissin hydraulic clutch slipping under load. The clutch slipped at times under heavy load/under throttle on super deep tracks. You could also feel the lever start to creep in towards your grip when accelerating out of corners at times. To combat this you had to remove the judder spring and add a fiber to the clutch pack. For 2021 the updated cone disk spring clutch feels much more linear than the 2020 and slips less under load. I say “less” because it can still slip if abused, but now without the judder springs, the KX450 gets traction to the rear wheel in a much better fashion. I experienced more rear wheel traction from area 2-3 in corners and was able to get on the throttle extremely hard without breaking the rear wheel loose (similar to a KTM feel). I also thought the engagement was a little wider and I could feel that when doing starts back to back with the 2020. It did feel like the clutch change Kawasaki made in 2021 did affect throttle response a little however. I thought the 2020 had slightly more excitement on low throttle situations, but also broke the rear end loose more when the track hardened up. I will gladly take slightly less throttle response with this new cone disk clutch in order to roll my corners better and exit harder. This change can also roll over into your 2019 or 2020 KX450 as well! You can simply order the basket, inner hub, pressure plate, fibers, steels, springs, clutch cover and update your older KX to the cone disk style. 

2021 Change Points:

Renthal 839 Fatbar (On The Track):

It’s just a bar Keefer!? Well… It isn’t just a bar, but it’s also a change to your rider traingle. Yes, of course you can put another set of bars on your older KX’s, but I am still going to tell you about this 2021 change. The 839 Fatbar is the same bar Honda uses on their CRF250/450R models and I love it! It has a lower height (91mm) than the older 971 7/8 bend and a rise that is only 51mm. I also felt slightly more connection to the front tire when pushing hard through corners. How? The larger diameter doesn’t flex as much on the ends of the bar, giving me more of a positive feel through the clamps down to the front wheel. The Renthal Fatbar wasn’t so rigid on slap downs that I felt I needed to go back to 7/8 on this chassis! Welcome to 2021 Kawasaki! Happy to have you! 

Weight Feeing (Chassis): The 21 KX450 is very free feeling yet connected, which makes this bike have a very light/nimble feeling through corners. I am able to lay it down with ease and cut down under a blown out rut almost as easy as a KTM/Husqvarna. I do get a little twitch on de-cel (which can be fixed with a fork spring change), but it wasn't a horrible or un-easy feeling. Straight line stability is still the same straight and arrow Kawasaki feel that you expect, but with added traction because of the clutch. The frame absorption is the best attribute to this machine and other manufacturers should take notice of how well this KX450 feels when the track goes to crap. The whole bike feels friendlier than a lot of other machines on square edge and the only other one that comes close in comfort is the Yamaha YZ450F

Engine Feel: Just in case you were trying to decide on if the 2021 KX450 is better than the 2020 version, scroll back up and read about the new clutch and what it does to the power of the new KX450. The 2021 comes on slightly smoother yet still has that lighter/free-revving feel and has minimal engine braking. I went with the stock ECU settings and the white coupler and seemed to like that the most when the track was deep or hard pack. The white coupler gave it slightly more throttle response, but didn’t make it jumpy feeling like the 2020 KX450. The 2021 KX450’s mid range has a nice amount of meat and the smoother pulling power of the top end/over-rev is noticeable on longer straights. I didn’t lose mid to top end pulling power with the black coupler (compared to the the white one), but I could ride the KX450 more aggressively through corners. I however feel like the black coupler is simply too smooth on deeper tilled tracks. The 2021 engine is super connected to the rear wheel and never steps out coming out of corners. This is an impressive power plant! I revisited my 2020 map and preferred the standard map with the white coupler for the 2021 version. 

Suspension: 

The 2021 Kawasaki Showa fork has tons of comfort, but is also too soft/divy for my liking on de-cel. The track I tested at required you to be hard on the throttle then brake heavily coming into the corner and the fork was too low in the stroke, which caused some oversteer. Going stiffer on the compression only hurt de-cel bump comfort, so I settled on going slower on the rebound, which helped some. I then went to a heavier spring rate (0.51) and the balance of the bike greatly improved off throttle. I would think some of that comfort would diminish, but I ended getting more comfort on de-cel bumps because the fork stayed higher up in the stroke. The shock is soft on high speed compression so going in on your high speed compression helps make the shock feel less empty on its end stroke. Below is a setting that I think can make a wide range of riders happier with their stock Showa suspension. 

2021 KX450 Base Suspension Settings:

Fork: 

Spring Rate 0.51 Spring (0.50 is stock) *If B level rider and over 200 pounds 0.52 springs are also a great option*

Oil Level: Standard

Compression:11-13 clicks out

Rebound: 11 clicks out

Fork Height: 3mm

Shock:

Spring Rate: Standard (190 pounds or over, try one spring rate heavier)

Low Speed Compression: 16 clicks out

High Speed Compression: 1 1/8 turns out

Rebound: 10-11 out

Confessional: 

I want to cleanse my sins right here! To the team green die hards out there, you’re right! I NEED to ride this machine more on my own time. Every year I say this and I end up only riding this bike to get you all settings and then I hand it off to one of my testers to create more content. I am NOT going to be doing that in 2021. Can you Keefer Inc. readers/listeners please hold me accountable for this statement in 2021? Every time I ride this bike I really enjoy it, so I must follow my heart and ride this more in 2021. Sincerely, Kris.  

2020 Kawasaki KX450 Vet National Race Build (Part One)

Written By: Joe Oehlhof

Five months ago, Keefer says to me while we were out riding, “Hey, you should race the Vet National.”  I responded back with, “Nah, it’s too much work getting ready for it.  I don’t have the time.” Of course immediately after Kris is done flapping his lips, his wife Heather chimes in with, “Yeah, you should race it. Kris will get you whatever bike you want.” My head sparked up and for some weird reason my mouth started to reply with, “Alright, in that case I am in”!  KK looks at Heather with a scoured look and says, “Wait, wait, wait…Whoa, Whoa, Whoa. You can’t be making those kinds of promises!”  A verbal agreement from any Keefer is a binding agreement so I immediately went Law And Order on his ass with “Nope, she said it.  That’s the deal.”  And Keefer replied with, “OK, we will get you a good bike and let you get it dialed in. Will you race it then?”  I reluctantly said, “Yes.”  Figuring it would probably never happen with Keefer’s schedule as well it being the fire season here in California (I am a San Bernardino County Fireman).  Never the less, we are roughly a week out from the Vet National and here I am preparing myself and a bike that I had about one month of time on.  

Getting the actual bike took a little longer than expected because of the “450 MX Bracket Shootout” and other factors, but in the end, Keefer decided to give me the 2020 Kawasaki KX450. Once he told me this, I got excited because I chose this bike as one of the top bike’s in this year’s 450 bracket. It’s a bike I feel really comfortable on, so I was excited to put some time on it, shake it down, and figure out what areas I wanted to address.

Luckily for me, Kawasaki provided a solid base to start from, which helps when you are in a time crunch.  The stock Kawasaki 450 is a great all-around bike for a wide range of riders, hence the reason why it got second in the bracket. For me the engine is strong yet very controlled, has a confidence inspiring compliant chassis, coupled with a smooth progressive powerband, that allows you to feel in control, while being able to push your limit. After spending a little over a week shaking this bike down, I came up with a few key areas that I wanted to improve. So here we go with phase one…

First area I wanted to concentrate on was the rider triangle which is really easy because I felt very comfortable with the stock bar position and bend. Call me old school but I do still like the 7/8” bar because of the flex that it provides. Kawasaki offers a lot of adjustability with several different bar position options with the triple clamp and two options with the foot pegs, but after trying several different combinations, I settled on the stock peg position and the bar mounts in the rear hole, facing in the forward position. Once I decided on this setup, I enlisted Pro Taper to provide that next level comfort. I went with the Carmichael bend Fuzion Bar because it’s a 1 ¼” bar, so you get the durability in case you have a crash, but comfort and flex of the 7/8” bar due to the option of locking or unlocking the cross bar. The locked position gives you a little firmer feel with less flex and the unlocked position gives you a bit more flex that mimics the character of a 7/8” bar.  Pro Taper also provided the oversized bar mounts, which easily bolted in using the rubber mounting and stock clamp. I rounded it out with the 1/3 waffle soft grips that added grip and comfort for my sissy hands.  

www.protaper.com

Next on the list of improvements was to boost the power for starts.  In stock form the Kawasaki KX450 provides a very broad manageable rider friendly powerband, but by no means is this bike slow. The power feels connected to the throttle, has excellent roll on bottom end with a strong pull through mid and top.  I had no complaints with the power delivery, I just wanted more. Don’t we all! I called the guys at Pro Circuit knowing that their relationship and years of experience with Kawasaki would provide me what I hopefully needed.  They sent me up with their Ti-6 Exhaust which provides a 1.5 pound weight savings as its titanium tubing is thing of beauty.  After bolting the system on (which is painless), I immediately noticed improvements throughout the power band.  It kept that smooth manageable roll on power, but increased it slightly, plus added more pull in the mid-range and thus improving the recovery time when shifting from second to third.  It also provided more over-rev just in case I got lazy (which is more common now that I am over 40) and I needed to leave the KX450 in second gear at times.  I know it sounds crazy to have a system that boosts power everywhere because usually it can be better in one area and not so good in another, but this system gave me exactly what I was looking for.  I have a couple more options to try to help move the power more, but that will be in phase two of this story so be watching for that.

www.procircuit.com

The last thing I was able to try in this phase of the Keefer forced “Vet National Bike Build” was another “comfort” piece. This piece made big improvements on the 2019 Suzuki RM-Z450 bike build, so we asked Kris Palm of FCP Engine Mounts to help me out for this green machine.  Factory Chassis Parts provided engine mounts with different a material and thickness (compared to stock) that allowed the chassis to flex differently yet shockingly provided a smoother overall feel, especially when the track is at its worst.  After a long day of testing with Keefer as well as doing two twenty-minute motos at Glen Helen, Kris from FCP bolted the engine mounts on and had me try them. If you have never ridden Glen Helen at 4pm just imagine a track that’s dry, most of the berms are blown out, has edgy off camber sweepers, kickers on the jumps, nasty braking bumps, and even nastier square edges through the corners, as well as down the next straight away. These conditions are commonplace here in California. If I was back home in Ohio, I may have not went this direction because of the soil differences, but since I am dealing with this kind of drier soil here on the west coast, I look for “comfort” when testing any part.  It’s miserable to ride a track as rough as GH when you’re not comfortable, but if you can make a bike work in those conditions, you have accomplished a great feat.  Like I said before, the Kawasaki chassis is (in my opinion) the best one out there, so I wasn’t sure if the FCP mounts would be able to improve upon that. In a nutshell, the mounts give the chassis just that little bit more flex, which takes away the transfer of energy that happens when you hit those bumps, so you don’t feel the sharpness of them as much. Upon entering corners, the FCP mounts take away some of that harsh hit you may feel and calms the movement of the bike down even more.  On initial lean through corners is where the mounts shine by allowing you to brake really hard and stick inside shallow inside west coast ruts.  Once in that rut, the bike stays planted and absorbs the acceleration chop better and continues down the next straight in a calmer manner.

www.fcpracing.com

I am really happy with the improvements we were able to make with bolt on parts and pieces from Pro Taper, Pro Circuit, and FCP.  Taking a good bike and making it a little better is always fun yet tough, so I am looking forward to phase two where I will be testing a remap of the stock ECU by Pro Circuit, modifying the suspension in order to dial it in for my weight and riding ability as well as a full clutch system from Hinson.  Stay tuned for that test as well as a Vet National story, to see how all of this preparation in one month’s time goes and the more difficult task of preparing myself with limited riding time due to firefighting duties, dad duties, and husband duties.  My hope is to give you guys that have regular jobs and family responsibilities a path to dialing in your bike, so you can enjoy that one day a week you get to ride. -Joe Oehlhof

If you have any questions about this test please feel free to email kris@keeferinctesting.com and he will try to do his best to answer any questions you might have.