Vortex CK6343 Racing Sprocket Kit HFRS - Hyper Fast Steel 520 Kit, 1 Down in the Front, 2 Up Steel Rear Fits Honda CBR600RR 07-15 Kit Gearing, Ratio 2.93, Front 15 Rear 44 OE Gearing, Ratio 2.63, Front 16 Rear 42 Kit Components, Front 3273-15, Rear 251AS-44, Chain 520SV3-112