Tuesday, February 8, 2011
Engineering advance #9: Alloy beam frame
Most modern motorcycles feature a beam frame that connects the steering head to the swingarm pivot in a nearly straight line. This stiff, light design sprang from the imagination of an influential Spanish engineer named Antonio Cobas. In 1983 his JJ Kobas 250cc Grand Prix racer was the first bike with such a frame. It was quickly copied by other Grand Prix racing teams and then into streetbike frames, such as the first Yamaha “Deltabox” chassis which first appeared on the manic TZR250 repli-racer in 1985.