Park Tool chain checker CC-4.2 Chain Checker

Park Tool chain checker CC-4.2 Chain Checker

A worn bicycle chain impairs shifting performance and can significantly wear other drivetrain parts, leading to more costly repairs. The Park Tool CC-4.2 Chain Checker is a drop-in gauge used for accurately measuring chain wear. The laser-cut CC-4.2 measures a longer section of chain and strategically touches the links at three points, allowing a quick and reliable determination of when the chain needs to be replaced.

The tool is compatible with all 5- to 13-speed derailleur chains (including SRAM® T-Type, SRAM® Flattop™, Shimano® XTR® 12-speed and Campagnolo® Ekar™ 13-speed) as well as single-speed chains. It is designed to show wear accurately at the 0.5%, 0.75% and 1.0% levels – the points at which most manufacturers recommend replacing the chain.

CC-4.2 features – General chain replacement guidelines:

• Single-speed chains (two-sprocket): replace when wear reaches or is just before 1.0%

• 5–10-speed chains: replace when wear reaches or is just before 0.75%

• 11–13-speed chains: replace when wear reaches or is just before 0.5%

Note: Many drivetrain manufacturers have their own specific chain replacement recommendations. Always check them with the relevant manufacturer.