Park Tool CC-4.2 Chain Wear Indicator/Checker

A worn bike chain causes poor shifting performance and can even wear out drivetrain components, leading to expensive problems. The Park Tool CC-4.2 Chain Checker is a drop-in gauge that measures bicycle chain wear. The laser-cut CC-4.2 measures a long section of chain and comes into contact with the chain at three points, making it quick and easy to determine when a chain change is required.

• Works with all 5-speed to 13-speed derailleurs (including SRAM® T-Type, SRAM® Flattop™, Shimano® XTR® 12-speed and Campagnolo® Ekar™ 13-speed) as well as 1-speed chains
• Indicates exactly when a chain reaches 0.5 %, 0.75 % and 1.0 % wear - the points at which most chain manufacturers recommend replacement.