The Kawasaki Motors Corporation have released the details regarding the two models of the full size motocross line, the KX250F and the KX450F.
After receiving a new chassis in 2012, the 450 will feature the Kayaba Pneumatic Spring Fork (PSF), as well as revised engine tuning, which includes a new piston and intake cam. The new 48mm KYB Pneumatic Spring Fork (PSF) eliminates the main fork springs by using compressed air as a spring. The reduced weight and inertia of the air spring improves smoothness, enhances the fork's ability to follow terrain contours, and cuts weight by 1.7 lbs. per set.
The frame and body components of the 250 have been redesigned for 2013 to create a more narrow bike. The aluminum frame is now 4 millimeters slimmer and the body components are more streamlined. Showa has upgraded the Separate Function Fork (SFF) for more dampening and increased the inner fork tubes to 48 millimeters.