Imagine the perfect motocross bike. Does it already exist? Or does it inhabit only thought, a hybrid outfitted with the best characteristics of each brand? If you're one of those types convinced perfection has been achieved and the faultless bike is already out there-maybe even in your garage-then I've got some bad news. You're either wrong-or afraid of change. Either way, we need to get you some help. So lie back on the strange-looking couch and listen carefully: The perfect bike doesn't exist. If it did, companies wouldn't go out of their minds redeveloping, reintroducing and reinventing perfectly competitive models. The 2006 Kawasaki KX250F is evidence of just that. It's a bike that in just two years racked up five national championships in arenacross and supercross competition and is celebrating the capture of a fiercely competitive outdoor title by Ivan Tedesco. With these results, Kawasaki could easily sit back and fine-tune what we thought was a good machine. But it didn't. It stood up to build a great one.
If you're the owner of a '04 or '05 KX250F (or Suzuki RM-Z250, for that matter), look in the garage and then look at this new baby that's exclusively Kawasaki (no sharing with Suzuki this year). Notice anything different? You should because there's a lot going on. It's not merely new here or there. It's all-new, completely changed and, more important, improved just about everywhere.
The first thing you'll probably notice is the aluminum perimeter frame that resembles, not surprisingly, the best-handling 250 four-stroke made to date. Although it seems like a big step for Kawasaki to follow Honda's aluminum frame with one of its own, it's not. Kawasaki has been building steel perimeter-framed motocross bikes since 1990 (longer than anyone) and has a boatload of experience building aluminum perimeter frames in its street bikes.
It's this experience that results in a chassis design lighter than the '05 model (a claimed 2.2 pounds), which has the sole assignment to deliver superior handling characteristics with an emphasis on power-to-the-ground traction. How does it work? Great. But more on that later. There's more new stuff.
The next big thing Kawasaki threw into its championship-winning bike was Showa suspension. Yep, Showa. Another similarity shared with the KX-F's red-blooded rival. The Showa twin-chamber fork replaces the lackluster unit on last year's bike and might just solve the biggest reason the green bike hasn't won our shootout. Other than the Showa component bolted on up front, Kawasaki's all-new chassis design also includes a radically new linkage-mounted to the bottom of the unpainted swingarm-and a Showa rear shock utilizing high- and low-speed damping. How does it handle? Great. But more on that later. There's still more new stuff.
Notice the radiator shrouds. Kawasaki is back in black for '06 with a two-piece cover that goes minimalist graphically and high-tech functionally. Kawasaki engineers claim the two-piece shrouds are designed to fit around the new aluminum frame, with the lower section (green) angled in for more clearance and a slimmer feel to the new chassis. Other plastic updates include holes in the sidepanels for more flow to the filter and even larger holes in the upper shrouds, next to the gas tank, to increase airflow through the radiators.
Speaking of radiators, there are big changes in this important department as well. The new Denso units aboard the '06 KX250F are thinner, have tighter spacing on the cores and sport a new fin design compared to the '05 model's. All this means improved cooling with less bulk. Kawasaki also included new radiator hose sizes and routing paths engineered to better balance the flow between the two cans.