RK is the leading manufacturer of drive chains for motorcycles in Japan. For more than 40 years RK has supplied all major Japanese motorcycle manufacturers as original equipment. Also in RC racing it 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 O-ring chains. The special shape of the X rings, the chain is sealed in four sealing points, the lubricant can not escape. In addition, the X-ring is used as an additional lubricant reservoir. The service life of the chain extends by approximately 30%. This technique was developed in RK for XW-Ring chain. - X-ring chain - Four sealing points - Lubricant cannot escape - Life is compared with the O-ring chain extended by 30% - Further development of the X-rings is the XW-rings