Motorcycle Pinion Gear GS500E GS500F KLX300R EL250 Fit For GS500E GS500F KLX300R 20-25 EL250 Chopper EL252 Ninja 250R EX250; standard 520 pitch front sprocket pinion fits engine output shaft of street offroad motorcycles machined inner splines complete tooth profile; slides onto drive shaft smoothly meshes tightly with 520 chain without or grinding uniform tooth layout evenly distributes chain tension; reduces chain jump surface abrasion under daily commuting trail riding 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 520 motorcycle drive chains