D.I.D Chain - 520ZVMX Road chainSuper Street X Ring (Replaces ZVM2) D. I. Ds ZVM X Series has greater strength than the VX Series and is designed for heavyweight motorcycles with tremendous torque and horsepower. The twisting action of theX Ring increases its sealing performance and its four contact points minimize power loss. The ZVM X Series Direct Energy Transfer, born from our experience in MotoGP, means greater stretch resistance under load.