Yamaha launched the YZF-R1 after redesigning the Genesis engine to create a more compact engine by raising the gearbox input shaft and allowing the gearbox output shaft to be placed beneath it. This design feature was revolutionary, called a 'stacked gearbox', it has set a precedent for other manufacturers to follow. This "compacting" of the engine made the total engine length much shorter overall, thereby, allowing the wheelbase of the motorcycle to be shortened significantly. This, in turn, allowed the frame design to place the weight of the engine in the frame to aid handling because of an optimized center of gravity. The swingarm was able to be made longer without compromising the overall wheelbase, which was a short 1385mm. Four 40mm Keihin CV carburetors fed fuel to the engine; 140 bhp was claimed by the factory. USD 41mm front forks supplied by KYB mounted 300mm semi-floating disk brakes. The instrument panel was electrical with a self diagnosis system and digital speed readout. The exhaust system utilized an EXUP valve, which controlled the exhaust gas flow to maximize engine power production at all revs. This created a high powered and high torque engine. The Yamaha YZF-R6 was introduced in 1999 as the 600 cc version of the R1 super bike.