The aluminum frame is always the big news. But, for Kawasaki this isn't exactly groundbreaking since they've had steel perimeter frames since 1990 and aluminum ones on their road bikes for some time now. And, it's safe to say their experience has paid off; we noticed nothing funky or bothersome when riding the new frame. When you can ride an aluminum-framed bike and not think about the frame, the mission has been accomplished.In the power department, Kawasaki is claiming their new 450 has more horsepower and useable torque than any bike in its class. While we won't know that for sure until shootout time, we can tell you the bike has plenty of grunt to lift the front wheel off the ground when you need it—even in the soft, deep loam of Competitive Edge. Like most 450s, the KX only gets faster as the track packs in and traction becomes abundant. In fact, some of us decided shifting gears was a pain and we'd rather just ride around in third gear to see if it would work. It did. And quite well actually. The KX450F pulled third gear even through tight corners and ruts, with only slight clutching for motivation.Something interesting is missing from the KX450F's transmission—fifth gear. The KX450F is a four-speed, close-ratio transmission which was built that way because (as Kawasaki puts it) on this bike, no one needs fifth gear. As far as anything you'll encounter on a motocross track, they are right.Suspension is provided by Kayaba components and their air-oil-separate fork worked well. The shock is the latest design with a higher-flow compression adjuster and all the trick coatings inside. We found little to fault with the suspension but we are playing with it to make the ride even better.All-in-all, the 2006 Kawasaki KX450F is a welcome addition to a class that's suddenly becoming crowded. Finally, all of our favorite colors will be represented come shootout time. Stay tuned to upcoming issues of Dirt Rider for the first tests and shootouts to follow.What kind of class is the KX450F stepping in to?
Click here to see the 2005 450cc Four-Stroke Motocross Shootout now online.