RK is the leading manufacturer of drive chains for motorcycles in Japan. For more than 40 years, RK has been supplying all major Japanese motorcycle manufacturers with original equipment. Even in racing, RK is the first choice of many teams in the MotoGP, the motocross or the Paris-Dakar Rally. RK XSO: This is an improved form of the O-ring chains. Due to the special shape of the X-rings, the chain is sealed at four sealing points, the lubricant can not escape. In addition, the X-ring serves as an additional lubricant reservoir. The life of the chain is extended by about 30%. This technique has been further developed into the XW ring chain at RK. - X-ring chain - four sealing points - Lubricant can not escape - The service life is extended by 30% compared to the O-ring chain - Further development of the X-rings are the XW-rings