Motorcycle Pinion Gear GSXR1000A GSXR1000RA 17-21 Fit For GSXR1000A GSX-R1000 2017-2022 GSXR1000RA 17-21; standard 525 pitch 17 tooth front sprocket engine output shaft specification for sport motorcycles machined inner splines complete tooth profile; slides onto drive shaft smoothly meshes tightly with 525 chain without grinding or evenly distributed tooth layout balances chain pulling tension; effectively reduces chain jump surface abrasion under torque acceleration solid blank material; fine tooth surface polishing craft; smooth tooth surface to lower chain friction loss extend life OEM matched outer diameter spline quantity; consistent tooth thickness delivers stable fit with all standard 525 size drive chains