Vortex CK6145 Chain and Sprocket Kit WSS - Warranty Steel Kit, Stock Gearing Fits Yamaha YZF-R1 04-05 Kit Gearing, Ratio 2.65, Front 17 Rear 45 OE Gearing, Ratio 2.65, Front 17 Rear 45 Kit Components, Front 3516-17, Rear 438S-45, Chain 530SV3-116