YBR125 motorcycle shaft sleeve set, plastic pipe (inner diameter 18 / outer diameter 24), steel pipe (inner diameter 14 / outer diameter 18) specifications and the middle shaft, rear flat fork interface completely match, direct replacement without adjusting the size; The plastic pipe cushions the vibration, the steel pipe strengthens the support, takes into account the shock absorption and structural strength, and ADAPTS to the dynamic stress scene of the flat fork; The plastic pipe adopts wear-resistant engineering plastic, and the surface of the steel pipe is rust-proof, which is suitable for long-term friction and outdoor environment. The inner and outer diameter and length parameters are consistent with the original car. After installation, the central shaft rotates smoothly without lag and slack; The rear flat fork/frame interface can be embedded in the corresponding position, and the installation is simple without additional polishing.