DID is original equipment manufacturer of many Japanese and European brands. Leading racing team in On-road and off-road sports rely on DID technology. DID 520VX3: The development of the successor to the proven 520VX3 is also based on a long experience DID experiences in MotoGP and fulfilled with the use of the patented X rings even the highest claims. - Longer life and less friction thanks to patented X-rings - Through direct power transmission technology, the driver gets an incredible acceleration resonance in the throttle response This is due to the most advanced technology to increase the chain force.