MD Short Take: 2007 Kawasaki KX450F and KX250F
By Dirck Edge
Photos by Evan Edge and Dirck Edge
It was pretty late in the game, but Kawasaki gave us the opportunity to test its latest supercross/motocross machinery - the 2007 KX450F and KX250F. Take a look at our preview article discussing the technical changes and updates made to these 2007 models. Let's get right to our riding impressions.
It is no surprise that James Stewart rode the 2007 KX450F to the AMA Supercross title this year. Stewart is a great rider, and we discovered that the 2007 KX450F is a great bike.
Russ Somers tested the 450 for us. Russ has been around a while, and is one of the fastest vets (both on a motocross track and in the desert). He could not stop raving about the motor on this bike. The KX450F pulls extremely hard just above idle, and has a huge spread of power. If anything, perhaps the KX450F hits a bit hard down low for the average rider. No one will be looking for more power on this bike, and it could certainly be competitive at the pro level bone stock. Russ also couldn't complain about the gear box, stock jetting or the bike's ergonomics. The new five-speed transmission offers desert and other off-road riders the chance to gear their bike for any circumstance. This motor can pull extremely tall desert gearing. The revised chassis is slim, and the bike is easy to move around on (even for 6'3" Russ).
Kawasaki claims that rear wheel traction is enhanced by frame and suspension changes for 2007, and our test bike did hook up well in conditions ranging from deep sand to hard pack.
The one area Russ noted for improvement was suspension. The forks worked well, by being plush on square edges, riding fairly high in their travel and avoiding harsh bottoming. On the other hand, Russ felt the shock was too soft and rode a bit low in its travel. Russ is a big guy, and this could be part of the problem, but he did note that the suspension could be better balanced front to rear. We didn't get the chance to try a stiffer spring on the shock, but this could be all the bike needs to balance it out.
The 2007 KX250F was tested by Evan Edge, a rider who has been on dirt bikes since the age of 4 and possesses some serious skill off-road, as well as on a motocross track. Evan was raised on two-strokes, but has ridden most of the modern four-stroke 250s.
The engine on the 2007 KX250F was even more surprising than the 450. For a 250, this bike absolutely rips! Evan felt it was easily the fastest 250 he had ever ridden and, just like the 450, had a broad spread of power than began down low and pulled hard all the way into the upper rpm levels.
After we set the sag for Evan's weight, and made slight adjustments to the rebound on the fork and shock, the suspension was hard to fault. For Evan's 150 pound weight, spring rates seemed about ideal, and the fork in particular was extremely plush and controlled. The back end hooked up well exiting corners, and the bike was very neutral in the air.
Although Evan felt the front end had a slight tendency to push in flat corners, this could have been simply a tire compatibility issue. Like the 450, the 250F has a slim chassis, and a relatively flat seat that is easy to move forward and backward on. The bike started easily, and was jetted relatively well for the near sea level conditions.
The 2008 models should be announced shortly, but might not be available for several months. If you can still find a 2007 KX, these bikes will please riders of just about every skill level.
Source: Motorcycle Daily