Park Tool CC-4.2 Chain Checker Tool A worn bicycle chain can

A worn bicycle chain can cause poor shifting and expensive drivetrain damage

Compatible with 5 to 13-speed and single-speed chains

It’s built for riders who value simplicity

Threaded hitch pin keeps rack steady and secure

It has been thoughtfully updated to respect the heritage of the classic design while incorporating modern elements for new generations

Park Tool CC-4.2 Chain Checker Tool A worn bicycle chain canA 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. It contacts the chain in three places, eliminating guesswork. Compatible with 5 to 13 speed and single speed chains, it indicates wear at 0. 5%, 0. 75%, and 1. 0%, matching manufacturer replacement recommendations. Measures bicycle chain wear accurately, preventing expensive