2011 Kawasaki KX450F - Dirt Rider Magazine

Performance through civility: Every change the Kawasaki made to the engine and chassis were aimed and making the bike easier to like, and better focused for a wider range of riders.

Old sayings like "No new is good news" stay in use because they often contain lasting truths, but it is rarely true when applied to new dirt bike models. In Kawasaki's case, though, years where existing models have received relatively minor upgrades have frequently been exceptional and memorable performers. So you could say "a little news is great news." And that is the case with the 2011 KX450F. The list of changes is modest, and many are in the form of refinements, but the sum of the changes adds up to a vastly improved machine for all levels of riders.In 2010 the KX hit super hard off the bottom like a class bully punching you between the shoulder blades. Getting the front wheel up wasn't an issue, but keeping it down could be. Add choppy suspension to the jumpy power and you had a potentially great machine that missed the mark slightly. It required a lot of attention and respect to ride in the rough. As a result, the KX450F felt big and clumsy in the face of the new nimble class warriors like the Honda CRF450R and the Yamaha YZ450F.

Kawasaki relied on another old saying for 2011: KISS - Keep It Simple Stupid. It started with the heart of the engine with a new piston, a larger volume muffler, ECU changes and a shift mechanism upgraded with a larger internal roller and more shift spring tension. While still not exceptionally quiet, the '11 has lost the raspy, blown-out sound common to recent KX four-stroke models. The KYB suspension already used prime components like the AOS fork with a slick DL coating on the lower legs and a shock with a 50mm piston, so the suspension changes were limited to revised damping settings front and rear and some anodized goodies to add a little zip to the look. Chassis upgrades are limited to stamped steel head-stay plates that replace machined aluminum parts. The steel plates are said to add a more compliant chassis feel. As far as rider accommodations go, the seat foam is a bit firmer for longevity and the seat cover have improved traction on the sides.

Despite the small list of changes the KX has undergone a profound personality alteration. The 2010 was brash and abrupt like Chad Reed, and the 2011 is quieter and has better manners like Ryan Villopoto. Starting the bike is still a snap, and probably as easy as a 450 gets without a magic button. The clutch pull is light for the class, and the shifting is quiet and smooth but solid. But where the 2010 power slammed into you, the 2011 has manners down low with smoothed and softened initial response. From down low the horses flow with ever greater energy. The "hit" is also smoother, more manageable and moved up slightly higher in the rpm range. The overall result is an engine that feels a little slower but isn't. It is calmer and lets the rider spend more brain and muscle power dealing with the track by the bike demanding less attention to control traction.We were fortunate to have our 2010 KX450F along as a back to back comparison on the fast and somewhat rough Racetown 395 track. When you ride both bikes in the same conditions you instantly realize what a profound improvement the relatively minor changes have produced. The new bike is still a missile, but initial throttle control is far less critical and demanding. You can actually relax riding the 2011.The story is the same with the suspension. The same springs we found too stiff in 2010 now generated zero complaints, and the general action of both the shock and fork feels smooth and supple. Racetown has some a fast straight with big rollers, and the suspension has the control to keep the bike calm and planted there. At the same time the fork deals with braking chop with enough control to tuck into the tightest inside ruts. The rear settles and hooks up exiting turns leaned over, but since the engine is still packing a lot of power, that is the one situation that still demands some throttle control. The traction is most impressive in a straight line where you can really feed it some fuel. This bike is still going to generate great starts, but it delivers without tearing your arms off. Sections that previously required exceptional throttle control now let the rider relax. A great side benefit is that the KX450F now feels lighter, more nimble and more willing and able to drop into tight turns. Tracking through high-speed rough is built right into this chassis, but now the suspension has joined the party.What about weaknesses? The shroud stickers have a lifespan of milliseconds in hot weather, and the black clutch cover looks old in a hurry. Those are flaws we can easily ignore. Dirt Rider will continue to gather more input at different tracks, so look for a full test in the magazine, and of course the biggest contest of the year: the 450cc motocross shootout.