... technical conversation. The main classifications of gear:1. Pinion gear2. Ring gear3. Duplicate gear4. Sprocket5. Pulley6 ... , synchronous ring. Motorcycle:Driven gear and parts, sprocket, starter pawl, ratchet, star gear, duplicate gear, pinion gear, gear ring, variable gear, pushrod ... exhaust valve seat. Oil pump parts:Oil pum gear, gear hub, various rotors, inner rotor and outer ...