Chain wear check tool

Park Tool CC-3.2C bicycle chain wear check tool

A worn chain presents operational problems and accelerates wear of the sprockets. The ParkTool CC-3.2 is a check gauge designed to accurately indicate when a chain reaches 0.5% or 0.75% elongation, thresholds most manufacturers recommend for replacement. For 9 and 10 speed chains, replace the chain when the gauge meets the 0.75% threshold by fitting snugly into the chain. For 11 and 12 speed chains, replace when the gauge adjusts to the 0.5% threshold. The CC-3.2 is a long, precise tool with permanent measurement marks.