... , whole tempering Heat treatment, surface hardening Dear customers, motorcycle roller chain 520 is for motorcycle TRANSMISSION SYSTEM.Roller chain Quality is vital for riding safety. As ... 25000~30000kms, which is strict quality test result. 1.Motorcycle Roller Chains:25H (04CH), 415, 415H, 420, 420H, 428, 428H, 520, 520H, 530 ...