A worn bicycle chain can cause poor shifting and expensive drivetrain damage. The Park Tool CC-4.2 Chain Checker is a drop-in gauge that measures chain wear accurately
Contacts the chain in three places, eliminating guesswork
Add feature, 1.0% wear mark, the point at which many single-speed systems recommend chain replacement
Laser-cut design contacts the chain at three points, providing quick and precise wear measurement
Compatible with 5 to 13-speed derailleur chains and single-speed chains
Indicates chain wear at 0.5%, 0.75%, and 1.0%, aligning with manufacturer recommendations for replacement
NOTE: General replacement guidelines: - Two-sprocket (single-speed) chains: replace chain at or just before 1.0% - 5-to-10-speed chains: replace chain at or just before 0.75% - 11-to-13-speed chains: replace at or just before 0.5% Many drivetrain manufacturers have unique recommendations specific to their components. Always double-check to be sure