Vortex CK6354 Racing Sprocket Kit HFRS - Hyper Fast Steel 520 Kit, 1 Down in the Front, 2 Up Steel Rear Fits Yamaha YZF-R1 98-03 Kit Gearing, Ratio 3, Front 15 Rear 45 OE Gearing, Ratio 2.69, Front 16 Rear 43 Kit Components, Front 3289-15, Rear 435S-45, Chain 520RV3-114