The CC-4 is a drop-in style gauge that measures bicycle chain wear. The laser cut CC-4 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 knowing when chain replacement is necessary. A worn chain will cause poor shifting as well as accelerate drivetrain wear. The tool works on any 5 to 12-speed derailleur chain and is designed to accurately indicate when a chain reaches .5% and .75% wear, the points at which most chain manufacturers suggest replacement.
Made in the USA.
The co-owners were hands-on bicycle repair folk back in the 1950s when bikes were simpler. Starting in the 1960s, bikes started getting more complex and the need for purpose-specific bike tools arose and Howard and Art met that need. Now more than 50 years into its journey, Park Tools is still developing and producing some of the finest bicycle tools in existence.