D.I.D is the number one motorcycle chain in the world. D.I.D chains are used by factory races teams from all manufacturers in race series everywhere. D.I.D's Pro-Street X-Ring VX Series Chains are high quality X-Ring chains with superior strength to withstand the horsepower of today's dual sports and trials bikes. The VX Series uses D.I.D's patented low friction X-Ring for maximum performance. Greater rigidity (7% higher than previous VM chain) creates smother handling, reduced power loss and quicker response. Highest value in all D.I.D series. D.I.D X-Ring has half the friction and 50 - 100% longer wear life compared to typical O-ring chains. Superior longer life than previous VM series. Solid rollers. Shot-peened parts. Pre-stretched. Extended riveted bushing "Anti-Kink" design. Replaces the Professional O-ring V Series and the Premium X-ring VM series chains. Average tensile strength of 8,210 pounds. Wear life index: 3500. Ideal for bikes and ATV's up to 750cc. Weight (per 100 links): 3.35 pounds. Includes clip-style master link. Half the Power Loss - Compared with Normal O-ring chains, D.I.D's patented X-Ring construction reduces friction by twisting between the side plates instead of being squashed. Normal O-rings and other makers' modified O-rings have squashed points that increase friction. The twisting action of the X-Ring disperses the pressure and minimizes power loss. 1.5 to 2 Times Longer Wear Resistance - Compared with Normal O-ring chains, the X-Ring's four contact points greatly increase its sealing performance. This keeps the dirt out and the lubrication in much better than any other O-ring. X-Rings have the greatest wear resistance of any other type of O-ring or non-O-ring chain. Note for installing X-ring chains: As X-ring chains are wider than standard roller chains, when fitting an X-ring chain to a motorcycle that was fitted with a non O-ring chain as original equipment, it is essential to check that there is proper clearance of the engine cases near the countershaft sprocket and any other places of close contact. Failure to do so could result in damage to the chain and motorcycle and could ultimately cause the chain to fail.