Park Tool CC-4.2 Chain Checker Groupe The rocker arm was optimised

The rocker arm was optimised to interface with sprockets that have from 11 to 32 teeth

Optimized gear steps across entire range

4 valve cores

Pins aligned with the external links

DO NOT use in the hubs

Park Tool CC-4.2 Chain Checker Groupe The rocker arm was optimisedA worn bicycle chain causes poor shifting performance and can actually wear out drivetrain components, causing more expensive problems. The Park Tool CC 4. 2 Chain Checker is a drop in style gauge that measures bicycle chain wear. The laser cut CC 4. 2 accurately measures a long section of chain and strategically comes in contact with the chain in three places, quickly and easily taking the guesswork out of determining when chain replacement is