Chain wear isn't visible until it's too late. By the time you notice skipping under load or rough shifting, you've already damaged your cassette and chainrings. The Park Tool CC-3.2 Chain Checker gives you an objective measurement before that happens, letting you replace a worn chain before it takes expensive drivetrain components with it.

The tool works by measuring chain stretch—the elongation that occurs as pins and rollers wear against each other over thousands of miles. A new chain measures exactly half an inch per link. As those internal surfaces wear, the effective pitch increases, and the chain no longer meshes correctly with your cassette teeth. The CC-3.2 checks for both 0.5% and 0.75% wear, the two thresholds that matter for replacement decisions. At 0.5% wear, you're in the replacement window for chains on 11-speed and 12-speed drivetrains where tolerances are tighter. At 0.75%, you've reached the limit for any drivetrain, and continuing to ride risks accelerated wear on your cassette and chainrings.

Using the tool takes about three seconds. Insert the curved end into any chain link, then swing the gauge body down. If the opposite end drops fully into the chain, you've hit that wear threshold. If it sits on top of the rollers, you're still within spec. No batteries, no calibration, no interpretation required. The stamped steel construction means the tool itself won't wear or flex enough to throw off measurements over years of shop use.... Read More