RK is the leading manufacturer of drive chains for motorcycles in Japan. For more than 40 years RK supplies all major Japanese motorcycle manufacturers as original equipment. Also in racing RC is the first choice of many teams in MotoGP, Motocross or even at the Paris-Dakar Rally. RK XSO: Here is an improved form of the O-ring chains. 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 is used as an additional lubricant reservoir. The life of the chain is extended by about 30%. This technique was developed in RK for XW-Ring chain. - X-ring chain - Four sealing points - Lubricant can not escape - Life is compared to the O-ring chain extended by 30% - Further development of the X-rings are the XW-rings