As the last of the major players in motocross manufacturing to produce a 450cc four-stroke, Kawasaki definitely suffered this summer at the outdoor Nationals. James Stewart, Michael Byrne, and Sean Hamblin were the only top pros on two-strokes, and their results surely suffered from it. Not that the KX250 two-stroke isn¿t a good machine, but when up against the best riders in the sport¿all on the more powerful 450cc four-strokes¿there¿s a point at which the 250cc powerplant can¿t be squeezed any harder, and in the end it just comes up a bit short.
The wait is over for the boys on green, however, as the all-new 2006 KX450F has finally arrived, and we were fortunate to be amongst a select few to take part in Kawasaki¿s press intro at Competitive Edge MX on Wednesday.
Like the 2006 KX250F, the new 450 features an aluminum perimeter frame that¿s been designed with years of steel perimeter frame, as well as ZX-10R sportbike chassis experience and expertise. The frame was designed so that the center of gravity and key chassis dimensions would work together to enhance the rear tire¿s ability to gain traction and drive the KX450F forward instead of squatting under acceleration. In addition, the engine sits in an upright position within the new frame, which is said to further increase the overall traction.
Kayaba AOS (Air-Oil-Separate) forks and a UNI-TRAK rear suspension system (featuring a Kayaba rear shock) are responsible for taking the hits and absorbing the bumps, a set of brand-new petal-style disc brakes provide the braking power, and newly designed, high-capacity Denso radiators keep the motor components running cool and efficient.
Speaking of the motor, a liquid-cooled, single-cylinder 449cc four-stroke engine delivers the power aboard the new KX450F. Featuring double overhead cams, four valves, a Keihin FCR40 carburetor, a tapered all-titanium head pipe, hand finished intake ports, and lightweight titanium valves, the new KXF is sure to have what it takes to compete in both Supercross and the outdoor Nationals in ¿06.
On the track at the Comp Edge press intro, our test riders were more than impressed with the ¿06 KX450F. The power is awesome, even out of the loamy, power-robbing corners, and the top-end overrev is smooth an efficient, as well. ¿The Kawasaki just rips out of the corners,¿ said Rich Taylor, our professional test rider. ¿Its got really good response, and it comes on really hard right out of corners¿¿ Said to be a very user-friendly power, the new KX450F is very strong, very smooth, and definitely has what it takes to compete with the best in its class in ¿06.
The suspension felt very good as well. Faster, more aggressive riders were forced to turn the compression in a few clicks up front to stiffen the ride, as the forks had the tendency to dive a little too far into the stroke when slowing down into corners, but aside from that it felt very well-balanced, and promoted a very positive, confidence-inspiring ride. Tracking is also very good. The new KXF responds well to rider input, and as a result can be easily guided into tight sections and inside ruts. In addition, the ergonomics and overall feel of the bike is very inviting. All of our test riders commented that it is a very easy bike to jump on and feel comfortable and confident, right off the bat.
Looking to further test Kawi¿s new 450, we headed out to Lake Elsinore MX today for a second day of riding. As a hard-packed, more jump and rhythm-oriented track, Elsinore allowed us to test other characteristics of the bike that may have otherwise been overlooked. In the air, the new KXF feels lightweight, well balanced, and is very easy to maneuver. In addition, the suspension did a great job of handling hard landings. Soft and compliant through the beginning of the stroke, the progressive Kayaba forks offer great bottoming resistance, and hold tough through even the gnarliest of flat-bottom landings. Traction can also be an issue at Elsinore, but the KX450F did an outstanding job of hooking up and tracking well through everything from slick high-speed corners to straight-lined whoop and rhythm sections. In addition, Kawasaki¿s new petal-style brake discs offer awesome stopping power, and help the KXF to dive into those tight, inside ruts with ease.
Still with only limited time on the bike, we¿re very pleased with what we¿ve experienced so far on the all-new 2006 KX450F. It¿s very obvious that the fellas at Kawasaki did their homework on both of their new four-stroke motocrossers for `06, and we can¿t wait to see how they will both stack up against their competition in our coming four-stroke shootouts¿although we¿re guessing very, very well. Stay tuned¿