RK is the leading manufacturer of motorbike drive chains in Japan. For more than 40 years, RK supplies all well-known Japanese motorcycle manufacturers as original equipment. Also in racing RK is the first choice of many teams in the MotoGP, in motocross or even at the Paris-Dakar Rally. RK XSO: This is an improved form of 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 by RK into the XW-Ring chain. - X-ring chain - four sealing points - Lubricant can not escape - Service life is extended by 30% compared to the O-ring chain - Further development of the X-rings are the XW-rings