LETTER OF THE MONTH
In my racing days, long before motocross came upon the scene, we had three engine displacement classes in which we could race. They were 250cc, 500cc, and Open class. Today, we have 250cc and 450cc classes. Can anyone tell me how the 450cc class came about? It just seems logical to me that it should be 500cc instead of 450cc.
Ken Phipps Moxee, WA The rule book limit used to be 550cc, but when Doug Henry won the 1997 Las Vegas supercross on the all-new YZM400, it kicked off the era of serious four-stroke racebikes. Yamaha and KTM fielded four-strokes, with displacements up to 540cc from KTM, while Yamaha upped its bike to 426cc. As those teams proved how good modern four-strokes could be, and with other brands developing their own bikes to join the party, the