Motocross Wars: the 1990s Have Arrived
Motocross Wars: The 1990s Have Arrived
ROUNDUP
THE 1990 MODELS ARE HERE! Well, at least the dirtbikes are. While announcements of their new streetbikes are still months away, all of the Japanese manufacturers have already released information on next year’s motocrossers, and, as always, the 250cc class looks like a hotbed of competition.
Kawasaki gives its new KX250 a dose of sportbike engineering via a steel, rectangular-tube, perimeterstyle frame, a first for a production motocross bike. New plastic components and wild, fluorescent graphics should make the KX a standout.
The KX also gets an upside-down, cartridge fork and its engine benefits from porting changes, a new exhaust system and stronger gears.
The Yamaha YZ250 is subtly upgraded for the coming year. The fork has revised valving, while the rear suspension gets a new lever ratio, different shock valving and a longer swingarm. The radiators and exhaust pipe are hung differently, for a lower center of gravity, and the brakes are claimed to be stronger due to new calipers and a larger front rotor. Engine changes include revised cylinder ports, a 5mmshorter rod and cylinder, and a heavier, larger-diameter flywheel.
There’s nothing radically altered on the 1990 Honda CR250R, either, but then it was the best of the 1989 MXers. It gets a new rear-suspension linkage, altered shock and fork valving, and slightly revised frame geometry. The rear hub has been changed again, the footpegs are wider and all of the plastic parts are redesigned and come in a different shade of red. Engine-wise, the CR is the recipient of different cylinder porting, while an additional clutch plate is said to reduce lever force and increase reliability.
Suzuki’s changes to its 1990 RM250 include all-new fork internals, a larger shock shaft, a 19inch rear wheel and revised brakes. And while the RM’s frame and bodywork are unchanged from last year, its engine goes to the starting line with revised porting, new clutch plates and a lowered second-gear ratio.
So, the 1990s are here, and if the new MXers are any indication, it’s going to be a very good year.
Ron Griewe
