Did you know that a worn-out chain will accelerate the wear of your drivetrain? All you need to do is stay on top of chain maintenance. The Park Tool Chain Wear Indicator is our recommendation to home mechanics.
The Park Tool CC-3.2 is designed to accurately indicate when a chain reaches .5% and .75% "stretch," the points at which most chain manufacturers suggest replacement.
How To Use:
For 9 and 10-speed chains, replace the chain just as the gauge fits the 0.75% side fits flat into the chain. For 11 and 12-speed chains, replace as the 0.5% side fits.