2021

Which Bike Is Best For You? 2021 Yamaha YZ450F Vs. Kawasaki KX450

The average shootout format seems to be an outdated model to me. Don’t get me wrong, I like doing shootouts, as well as viewing their rankings after all is said and done, but is it really telling you, the potential consumer, what you want to know or is it more of a scene on the side of the freeway that you just have to look at? I have done shootouts for 20 plus years and although fun and interesting to do, I just don’t know if it’s something that gives buyers the most information in these ever changing times. Just because a certain bike wins a shootout doesn’t mean it’s the best bike FOR YOU! I get countless emails about which bike is right for me and most of them say that they watch every shootout video, but they still can’t decide. So if you are one of these potential consumers that still can’t make up his or her mind, then this article can help you hone in on why a certain bike could be right for you. As a production test rider for several manufacturers over the years, I am wired to think about all different types of riders when I evaluate a certain machine. In this article I will try to break down each machine, which one does certain things on the track better than the other and hopefully give you more purchasing knowledge on which way you’re directing your hard earned money. We will be doing these types of matchups with other machines down the road, but we hope this gives you a more clear cut path on if one of these two machines are right for you. 

Why Yamaha Vs. Kawasaki: 

If there are two bikes in the 450 class that having similar characters it would be these two machines. These two bikes will most likely be the leaders in most of the shootouts you will read or watch in 2021. The YZ450F and KX450 both have great suspension, solid engine characters and each have a chassis that is stable and forgiving. However that doesn’t mean that they are one and the same. Each have specific traits about them that are better than the other and we are here to break those down for you. Even if we do break all of the nuts and bolts down to you, it’s up to you to know what type of rider you are. Are you a front end steering rider? Do you like an exciting or smooth engine character? How often do you ride? Do you just ride or do you race occasionally? These are the questions you should be asking yourself before you spend 10K on a new dirt bike.

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What Is It Like To Ride A 2021 Kawasaki KX450?

Weight Feeling (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 easier than a Yamaha YZ450F. I do get a little twitch on de-cel (which can be fixed with a heavier fork spring change), but it isn’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 new 2021 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. If the suspension was a little stiffer, I think the chassis would shine even more. The whole bike feels friendlier than a Yamaha YZ450F in fast/choppy situations once you put a heavier fork spring inside the Showa fork. If you are the type of rider that rides faster tracks with square edges or lots of chatter there is no better frame than the KX450.  

Engine Feel: The 2021 KX450 comes on slightly smoother than the Yamaha, yet still has that lighter/free-revving feel and has minimal engine braking (less than a Yamaha). I went with the stock ECU settings and the white coupler and it 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 YZ450F. The 2021 KX450’s mid range has a nice amount of meat and the smoother pulling power of the top end/over-rev is manageable 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 KX’s engine is super connected to the rear wheel and never steps out coming out of corners, but the Yamaha’s excitement does get you on top of soft dirt a little quicker than the KX. The KX has a KTM 450’esq feel in certain areas of the track when it’s hard pack. The Yamaha lights up the rear wheel much quicker than the KX in these situations (even when you change the YZ’s mapping), so having a smoother roll on when the track is harder helps the green machine. The KX is an impressive easy to manage power plant!

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.  

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What Is It Like To Ride A 2021 Yamaha YZ450F?

Engine Feel: So what exactly are you getting with the 2021 Yamaha YZ450F engine? You’re getting a connected rear wheel feel out of corners and more RPM response than a KX450. I don’t feel like you’re necessarily getting more bottom end pulling power than a KX, but the initial crack of the throttle is better (almost too much) right when you get ready to stab that throttle (anywhere in the RPM range). Where I feel like the Yamaha is best is through mid range-top end pulling power. The difference in “meat” through the mid-range once out of corners is impressive. We talk about third gear a lot in these tests and how important that gear is to the rider. If third gear is not useable in corners, it’s tough to ride smooth and forces the rider to be more active on the bike, which could result in getting more tired more quickly. The Yamaha has more mid-range pulling power, which allows you to use third gear through corners easier than the KX450. Usually you will have to fan the clutch a little on the KX to get the engine to recover and get back into the upper RPM range, but with the YZ450F you can just roll on the throttle and it will start pulling you down the track immediately. Top end pulls farther in second and third gears and will not sign off as much as the KX450 does. Even though a 450 shouldn’t be revved out, let’s be real, sometimes we are lazy and DO NOT have perfect riding technique, so it’s nice to leave it in second gear and use that gear all the way to the next corner. It happens right? This Yamaha engine character helps you do that better without sounding like Justin Barcia at Southwick.

Weight Feeling (Chassis): The YZ450F feels stiffer in the frame around the track than the KX. However don’t get scared off by the word “stiff”. It’s not rigid by any means, but just has a stiffer feel and doesn’t have that  wallowy sensation. Let’s go over this a little…The KX chassis is softer near the front of the machine and on the down spars of the frame. Now I am not going to sit here and tell you that the Yamaha is a cornering dream and that it corners better than the KX, because quite frankly it’s easier to get into area 1 of the corner on the KX450. Area 2 of the corner the KX feels lighter and is easier to lean, but in area 3 (exit) of the corners the Yamaha seems to hook up better. I will say that cornering stability is better on the Yamaha when the rut is rough and hacked out, but if you’re riding some sticky, long ruts the KX is easier to maneuver. Straight line stability is good on the Yamaha but the KX is great. The KX frame absorption or the transfer of energy when hitting bumps just has a softer feel to it on the green machine. The Yamaha doesn’t feel as long, but has slightly more energy (when hitting bumps) through the bars than the KX. I do feel when the track gets rough the Yamaha is easier to push your limits, but to me most of that is suspension.

Suspension: The stiffer setting that Yamaha has compared to the KX amazingly still has more comfort.  I mean I guess it shouldn’t be a shock, but I am wired to think if I go stiffer, my comfort sensation on the track might go down. The comfort that you’ve grown accustomed to with the KYB SSS/Yamaha suspension is still there! Even though both ends have more hold up and less pitching than the KX450, I still ended up going stiffer on my settings. I felt like under throttle out of corners the rear of the bike (shock) was too low and I was getting a harsh mid stroke feel. Going in one click stiffer on the low speed compression as well as in (stiffer) on the high speed compression a quarter turn will help with hold up. I also wanted to calm the rear of the bike down on braking bumps so I made a huge change to the rebound just to see how the YZ450F took it and to my surprise it really liked a slower shock setting, so don’t be scared to go as much as three clicks in (slower) on the rebound. Again, for 2020, Yamaha’s goal was to increase performance as well as comfort and they somehow weaved both seamlessly together for a no fuss suspension spec that I think will please a wide range of riders.  

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Which Bike Is Right For Which Type Of Rider? 

Even though both of these bikes are great machines we put our thinking caps on and thought of a few different types of riders. Below is a list of a few labeled riders, so if you think you can relate to one of these riders below, picking the correct color should be made easier for you. However, if you still can’t make a decision after viewing these, my door is always open at kris@keeferinctesting.com. Maybe I can help you further. 

Vet Rider (Less than 200 pounds): Yamaha YZ450F

Vet Rider (More than 200 pounds): Yamaha YZ450F

Aggressive Light Rider (under 170 pounds): Kawasaki KX450

Lugging/Lazy/Smooth Type Of Rider(Gear High): Yamaha YZ450F

Ergonomics For The 6’0 And Under Rider: Kawasaki KX450

Ergonomics For The 6’0 And Over Rider: Kawasaki KX450

Front End Steering Rider: Yamaha YZ450F

Rear End Steering Rider: Kawasaki KX450F

West Coast MX Rider: Kawasaki KX450

East Coast MX Rider: Yamaha YZ450

Off-Road/GP Rider: Kawasaki KX450

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Who Wins The Durability Test? I have ridden both of these machines a lot and will say that the Yamaha YZ450F has given me almost no problems. The Kawasaki’s subframe has cracked on me near the muffler mount as well, as well as some of the bolts strip out on me. The Kawasaki isn’t “unreliable”, I just do less maintenance  to the Yamaha. If you’re meticulous and are mechanic minded, the KX450 is fine, but if you’re a wash it/filter/oil/ride it type of guy like I am most of the time, the blue bike doesn’t give you any lip. To me it is very difficult to beat the durability of a blue bike. I have literally just changed the oil/filter, air filter, a clutch or two and have ridden the shit out of the bike (100 hours). Not even a valve check.  

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Who Wins The MSRP/Contingency Battle? If you are racing with your new machine and looking to make the most out of your investment then to me Team Green sets the standard. Team Green has a ton of on track support at local and regional events, but if I was a local racer and looked at each manufacturer contingency programs, I know I could make more money back with the Team Green rewards program. If racing isn’t your thing, then disregard this option. 

Who’s Best In Which Category? 

If you’re really dissecting on which part of the motorcycle is most important for you when riding, below is a ranking on who is better (albeit it could only be slightly better) in over 30 categories! Again, there is no winner or loser in this test, but it’s about which bike is best for you!

ENGINE:

Low End Power: YZ

Mid Range Power: YZ

Top End Power: YZ

Over-Rev: YZ

Roll On Acceleration (Control): KX

Throttle Response: YZ

FI Setting: YZ

HANDLING:

Straight Line Stability: KX

Turning Cornering: KX

Steer Effort (Low Speed): KX

Steer Effort (High Speed): KX

Maneuverability: KX

Weight Feeling: KX

C.G. Feeling: KX

Weight Bias: KX

FORK:

Comfort: YZ

Performance: YZ

Bottoming Resistance: YZ

SHOCK:

Comfort: YZ

Performance: YZ

Bottoming Resistance: YZ

BRAKES:

Front Brake Power: KX

Front Brake Feel: YZ

Rear Brake Power: KX/YZ Tie

Rear Brake Feel: KX/YZ Tie

RIDING COMFORT:

Machine Size: KX has a roomier rider triangle and is narrow feeling

Handlebar Feel: KX/YZ Tie Both have good bar bend

Grips: YZ

Seat Position/Height: KX

Seat Shape: KX

Seat Stiffness: KX

Leg Room: KX

Vibration: YZ/KX Both have minimal vibration 

Engine Noise: KX is much quieter than YZ






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.

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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. 

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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! 

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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. 

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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.