The wear‑resistance, tensile strength and fatigue resistance of motorcycle chains and sprockets are directly determined by raw‑material selection and heat‑treatment processes. These indicators also serve as the key distinction between ordinary spare parts and high‑quality transmission kits. Drawing on 20‑year manufacturing experience in this industry, Renqiu Shijia Motorcycle‑Parts Co., Ltd. adopts differentiated alloy‑steel raw materials for products with different positioning, striking a balance between product performance and cost‑effectiveness.
The bushing is made of 20CrMnMo alloy steel. This material boasts excellent toughness and resists cracks under repeated impacts, which effectively slows down bushing wear. Rollers adopt No.10 steel to strengthen shock‑resistance and withstand frequent impacts during motorcycle startup and bumpy‑road rides. The hinge pin uses 30CrMnTi material to greatly improve tensile strength and lower the risk of pin breakage. Link plates are manufactured from 45Mn manganese steel for outstanding fatigue resistance, preventing deformation and fracture after long‑time high‑speed operation. High‑grade lubricating grease is also applied to further cut down internal abrasive loss.
Ordinary open‑type chains require frequent maintenance. They are prone to elongation and accelerated wear under dusty and rainy surroundings. Built‑in rubber sealing rings of O‑Ring sealed chains lock lubricant inside pin clearances and block dust and silt intrusion, greatly extending maintenance intervals and overall service life. Demand for sealed chains keeps growing in the high‑end overseas aftermarket. Shijia Motorcycle‑Parts runs three major product lines: standard‑duty, heavy‑duty and O‑Ring sealed chains, covering working conditions from daily‑commuter motorcycles to heavy‑load‑intensive scenarios.
Raw materials lay the foundation, while heat‑treatment techniques decide whether material properties can be fully unlocked. The factory is equipped with complete‑set equipment for heat treatment, quenching and tempering. Temperature and duration parameters are strictly controlled to guarantee uniform and stable hardness for every batch of chains and sprockets. A full range of testing devices including Rockwell hardness testers, Vickers hardness testers, tensile‑strength testing machines and salt‑spray testers are used to inspect finished‑product tensile property, hardness and corrosion resistance. Every batch exported to overseas markets meets performance‑related standards.
