EK Chain’s new Zero Stretch Technology virtually eliminates measurable chain stretch in the first 600 miles (1000km) of use. ZST puts an end to the hassle of retensioning the chain after the initial break-in period, when most chain stretch occurs. For racers, this can mean going several race weekends without a single chain adjustment. ZST also helps to ensure that your chain will stay within wear tolerances throughout its entire service life. ZST is standard on the 530ZZZ chain, and available as an option on the 520RXO chain and all MVXZ series chains.