2011 Kawasaki KX450F Comparison

JC Hilderbrand | December 22, 2010

The Kawasaki KX450F is a conundrum our testing crew has to face every year. The big KX-F lumbers into the shootout and immediately starts knocking testers’ perceptions askew with a ridiculous engine. It would be uncommon not to see the Kawi ranked at the top of the riders’ assessment for power delivery, overall production, effectiveness and character. The problem is that it kind of overwhelms the senses and it’s easy to get focused on how gnarly the powerplant is. Known as the class brute, Kawasaki made minor updates for 2011 that won’t change its reputation, but it does tone the green meanie to a certain level. A reshaped piston, longer, hotter spark settings from the ECU and new fuel and ignition mapping smooth out the Kawi without taming it down.

The Kawi is built to rip through the range that most riders will probably use, but up top it falls from the 51.2 horsepower peak faster than the rest of the bikes. It’s not a very graceful retreat either, but more of a major topple. Just take a look at the dyno curves, that green line starts losing altitude early and quickly. Getting a launch off the start is a matter of self-control and precise clutching. The Kawi tied with Honda for the best holeshot time (4.28 seconds) but had a lower trap speed as a result of lower gearing. The third-gear roll-on indicated that the beefier the low/mid-range, the more unnecessary tire spin as the Kawi, Yamaha and Suzuki wound up as the bottom trio while the smoother, taller-geared Honda and KTMs snatched the top spots. We were also glad to discover that the exhaust note is no longer the terrible, raspy blast of the past few years. The muffler can is much more tolerable to a trackside spectator and registered at 94.6 dB.

2011 Kawasaki KX450F
The Kawasaki will get you up and over anything. It’s the slowing down and turning for the next jump that’s more difficult.

The engine isn’t the problem, never has been. What the Kawasaki needs is to go on a massive diet and work on its reflexes. At 252 pounds with a full 1.9 gallons of premium, the KX-F is the heaviest bike in the test by a good margin (12 pounds more than the Honda). It also just feels big. The cockpit is wide open and a favorite for larger riders. Standing up while riding is easiest on the green bike, and though it’s large, it isn’t thick. The midsection and radiator shrouds provide ample amount of grip for the legs without feeling fat, or at least curvy, like the Yamaha.

Kayaba suspension provides a taut feel. The KX-F is big, fast and aggressive, and the suspension reflects that with a solid feel. Our batch of riders liked the performance of the DLC-coated fork and 50mm shock piston enough to land it in second-place for the category. As with the rest of the Kawasaki, the harder you ride it, the better it reacts. For some this can be difficult with such an aggressive motor and dominating physical stature, but highly skilled riders or someone large enough to really muscle it around will find that it pays to keep charging.

One area that needs improvement is the brakes. With components like KTM’s Brembo calipers and Yamaha’s Nissin binders putting a serious pinch on things, the Kawasaki’s feel dated. The front brake in particular lacks feedback and still has its wooden feel. It’s amazing how much you don’t realize it until riding another bike, but once those right fingers grab something else, the KX-F brakes will be disappointing.

So compared to year’s past, Kawasaki’s powerplant is still eye-opening but the abundant power delivery is a tad more manageable. Like we said, once you’re in the throttle, those little concerns seem to melt away – actually it’s more like being blown away. Blue-anodized damping adjusters on each fork leg and a two-tone gripper seat add race-team styling, which is nice, but in the end the KX-F needs to shed weight and speed up the handling department.

2011 Kawasaki KX450F Rider Impressions:

Bret Milan – 6’4” – 210 lbs – Intermediate
The Kawasaki has the best powerband – fast and fun, but not for the faint of heart. It packs a throaty punch that makes it fun to ride and has plenty of top-end pull to get the job done. With a powerband as wide and strong as the Kawasaki’s, it could make any gearing feel great. This is the best motor of the bunch for motocross, but it could be more than you need in some conditions. It might be worth investing in Kawasaki’s kit to modify the fuel injection and ignition mapping.

Overall the suspension felt a bit soft, but it is closer to being right for bigger guys than some of the other bikes in the test. The Kawasaki is definitely one of the best “tall guy” bikes in the test. For some reason, I love the stock Kawasaki handlebar bend! It took more effort the get the Kawasaki through corners. I felt like I needed something to bank off of in order to be aggressive. Stability, on the other hand, is the Kawasaki’s strong point. It’s easy to see why Kawasaki has been so strong in WORCS competition for so long. The brakes were adequate, but the front brake is a little more spongy and weaker than some. It really isn’t bad at all, but all the bikes have such great brakes now that the Kawasaki’s just doesn’t feel as good as the others.

2011 Kawasaki KX450F2011 Kawasaki KX450F2011 Kawasaki KX450F

JC Hilderbrand – 5’11” – 190 lbs – Novice
This bike is the opposite of the Honda. There’s nothing subtle or deceiving about it. It’s got a boatload of power and it comes on right now. Keeping the front end down can be a struggle when the traction is good, and when it isn’t, keeping the rear end behind the front becomes the challenge. The KX-F is easier to ride than last year and the amazing engine lets me get away with being lazy. The top-end falls really hard, but I never had much of a reason to ride up in the rpm. The only thing that bummed me out about lugging around on the Kawi is that shifting it is a pain. I’ve got gripes about Yamaha’s tranny and the 350 as well, but Kawi’s drivetrain is at the bottom of my list because it’s clunky.

With the Kawasaki you have to squeeze tight to go fast, and equally as tight to slow down. I loved the slim front brake lever, but it just didn’t have any feel to it. Basically turning was a chore since you had to yard on the front lever and then shove the bars down. The Kawi loves to stand up straight and leave big rooster tails. It’s easy to see why the flat track guys have had such luck with this monster.

2011 Kawasaki KX450F
Run it wide, pitch it in and lay on the throttle.

Kyle Lewis – 5’10” – 180 lbs – Vet Expert
The KX has a good initial hit but the motor signs off pretty fast. We tried a different ignition setting which allowed the bike to rev more, but took the torque away from the motor. I went back to the original setting. Throttle response was a little lazy, which sounds crazy because the bike has good hit off the bottom, but the throttle response is a little slow. The clutch was one of the strong points on this bike. Once I set the lever, I didn’t have to mess with it – good power and grabby. I didn’t care for the brakes on the Kawi. The front had a hard feel, with not a lot of power. It would bite and then go away, and the rear brake didn’t have good progression.

We had to move the forks down in the triple clamps 5mm because at the stock setting the front end would dive and wanted to tuck underneath me in the corners. Just 5mm seemed to help quite a bit. I didn’t have to adjust the suspension much. I stayed close to the neutral settings. Performance of the Kawi felt good. It was smooth with no major issues. The balance is close, but after raising the front end, to get it to stop tucking, the rear felt a little low down the straightaways for me. The handling felt strange because it would turn tight, but the bike itself felt long. On high-speed cornering it was slightly unstable.

2011 Kawasaki KX450F
Our faster, larger testers were particularly happy with the Kawasaki KX450F.

Chris See – 5’10” – 165 lbs – Pro
The Kawasaki 450 has great bottom-to-mid power, but as I hit the top-end power it hit a flat spot and just wouldn’t go any further. Because of the lacking top-end I had to short shift a lot. I would go down one tooth on the rear sprocket so I wouldn’t have to shift so much. One scary thing that I had happen was the bike would almost half shift and pop out of gear when under power. It happened on a few long straightaway sections. Basically the shifting felt notchy, but the clutch was butter.

The fork is extremely harsh, the first three inches of suspension are very supple, but by the time it hits the mid-stroke it spikes back. The rear was opposite for me being super stiff and firm, so we moved the sag to 106mm and went softer everywhere on the shock which made it work to my liking. Since 2008 this bike has had a hard time turning, and the 2011 KX-F still stands around the mid-way point in the cornering performance. Even with the fork raised nearly to the handlebar, it still liked to stand up on me. At the end of the day, though, in rough straightaways this bike was straight as an arrow and tracked great. I struggled to be comfortable on this machine since it seems to be built for the taller motocross rider. But, the front brake was very grabby which was great for my tastes.


JC Hilderbrand

Off-Road Editor| Articles | Hilde is holding down the fort at MotoUSA’s Southern Oregon HQ. With world-class dirt bike and ATV trails just minutes away, the hardest part is getting him to focus on the keyboard. Two wheels or four, it doesn’t matter to our Off-Road Editor so long as it goes like hell in the dirt.

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