Park Tool CC-2 or CC-4 CHAIN CHECKER Bicycle Chain Wear Indicator

• A worn chain is inefficient " adds resistance to pedaling" and shifts poorly.
• Works on all bicycle derailleur chains.
• Measures how worn the chain is so you'll know when it needs to be replaced.
• If you continue to ride a worn chain, you run the risk of ruining your cassette and chainrings which are expensive to replace
• A worn chain is inefficient " adds resistance to pedaling" and shifts poorly.
• For 9 and 10-speed chains, replace the chain just as the gauge fits the 0.75% side, fits flat into the chain.
• For 11 and 12-speed chains, replace as the 0.5% side fits.
• Made from precision laser-cut steel with permanent measurement markings.

CC-2

The CC-2 is compatible with all derailleur chains. Simply insert the Chain Checker’s pins into two links, lightly press the swing arm gauge, and then check the gauge window for an accurate reading. For 9 and 10-speed chains, replace chain at or just before the 0.75% readings. For 11 and 12-speed chain, replace at or just before the 0.5% reading. Check with manufacturer for specific replacement instructions.

CC-4 

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 (including SRAM® AXS®) and is designed to accurately indicate when a chain reaches .5% and .75% wear, the points at which most chain manufacturers suggest replacement.