RK is the leading manufacturer of drive chains for motorcycles in Japan. In racing, too, RK is the first choice of many teams in MotoGP, motocross or even the Paris-Dakar Rally. Manufacturer: RK. Due to the special shape of the XW rings, the chain is sealed at six sealing points, thus preventing the loss of lubricant under all conditions - the service life is extended by up to 50% compared to an O-ring chain.