Supercross Superbike

SUPERCROSS SUPERBIKE

MOTOCROSS HISTORY will be made this fall when Honda offers the first-ever aluminum-framed production motocrosser to the buying public.

Based on a prototype campaigned in the All-Japan MX Championship, the 1997 CR250R’s roadrace-style, boxsection aluminum perimeter frame features twin upper spars and a double cradle. Weight savings are said to be more than 4 pounds compared to the previous steel CR frame, and 6 pounds compared to the steel perimeter frame employed on Kawasaki’s KX250 and 125. Other advantages include a thinner profile, a roomier rider compartment and seamless sides to prevent the rider’s boots from catching.

The CR’s suspension had to be totally redesigned to match the new frame, prompting a return to Showa components (the ’96 model used Kay abas) front and rear. The 1 mm-larger (47mm) inverted fork mimics works units with a twin-chamber design, coated inner surfaces and minimal overhang below the axle. The Pro-Link rear suspension utilizes a new linkage with a different ratio, a new, lighter aluminum swingarm and a redesigned rear shock with highland low-speed compressiondamping, rebound-damping and spring-preload adjustability.

The most powerful motor in the 250 class didn’t go untouched, either. Lifted from the race team is the Keihin powerjet carburetor, whose auxiliary main jet stays open below 8000 rpm for stronger throttle response. This works in conjunction with a new, mapped digital ignition system that monitors the rate of engine-rpm increase to give a measure of traction control through ignition timing. Cylinder port timing, the flattop piston, the combustion chamber and the exhaust powervalve were all updated to give a smoother, stronger, wider power spread. Smaller changes include a 20mm-larger rear disc brake, a one-piece radiator with increased coolant capacity and a reshaped handlebar.

Price? Shocking, in that the thoroughly revised CR250 will sell for $5699-just $300 more than last year’s model. It’s scheduled to hit dealerships in November.

Jimmy Lewis