The Park Tool CC-4.2 Chain Checker takes the guesswork out of knowing when it’s time to replace your chain. A worn chain not only impacts shifting performance but can also accelerate wear on expensive drivetrain components, resulting in premature replacement.

This precision, laser-cut gauge measures a longer section of chain for improved accuracy and makes contact in three strategic points, ensuring consistent results every time. Simply drop the tool into place, and you’ll instantly see whether your chain has reached 0.5%, 0.75%, or 1.0% wear—key replacement thresholds recommended by most manufacturers.

Compatible with 5 to 13-speed derailleur chains, including SRAM® T-Type, Flattop™, Shimano® XTR® 12-speed, Campagnolo® Ekar™ 13-speed, and single-speed chains, it’s an essential workshop or home mechanic tool to keep your drivetrain running smoothly and extend the lifespan of your components.

Key Features

• Precision Measurement: Laser-cut gauge contacts the chain in three places for accurate wear readings.
• Compatibility: Works with 5 to 13-speed derailleur chains, including:
• SRAM® T-Type and Flattop™
• Shimano® XTR® 12-speed
• Campagnolo® Ekar™ 13-speed
• Single-speed chains
• Wear Indicators: Measures at 0.5%, 0.75%, and 1.0% wear—thresholds recommended by most chain manufacturers.
• Build Quality: Made in the USA and backed by Park Tool’s limited lifetime warranty.
• Ease of Use: Drop-in style gauge makes checking chain wear quick and intuitive.