CG125 motorcycle auxiliary shaft, shaft length 158MM, shaft diameter, spline structure and CG125 gearbox completely match, directly replace the original auxiliary shaft, without changing the internal structure of the gearbox; Using high quality alloy steel processing + surface hardening treatment, shaft body hardness is high, anti-wear, can withstand the transmission load of the gearbox gear stably, long-term use without deformation; Precision spline and gear hole fit degree is high, ensure smooth power transmission without lag, reduce transmission noise and power loss; The surface treatment process can resist oil corrosion and environmental corrosion, and is suitable for long-term high temperature and high humidity working environment of the engine.