Park Tool CC-4.2 Chain Checker Tool
Tools
Park Tool CC-4.2 Chain Checker Tool
Park Tool CC-4.2 Chain Checker Tool
The Park Tool CC-4.2 Chain Checker Tool is a laser-cut drop-in gauge that measures chain wear at three calibrated points simultaneously, giving you a fast, definitive reading on whether your chain needs to be replaced. Read the overview
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Overview
Why is the Park Tool CC-4.2 a better chain checker than a ruler?
The Park Tool CC-4.2 Chain Checker Tool is a laser-cut drop-in gauge that measures chain wear at three calibrated points simultaneously, giving you a fast, definitive reading on whether your chain needs to be replaced. Compatible with 5 through 13-speed derailleur chains and single-speed chains, it reads wear at 0.5%, 0.75%, and 1.0% stretch, which aligns with the replacement thresholds recommended by most drivetrain manufacturers. Catching a chain at 0.5% to 0.75% wear preserves the life of your cassette and chainrings. Waiting until 1.0% or beyond means the chain has already begun to wear matching components.
A worn chain is the most common and most preventable source of expensive drivetrain damage. The CC-4.2 makes checking chain wear fast enough to do at every service. The three-point contact design eliminates the guesswork of a single-measurement tool and gives you confidence in the reading regardless of where you sample the chain.
All the specs
- Wear Indicators
- 0.5%, 0.75%, and 1.0% stretch
- Compatible Chains
- 5 to 13-speed derailleur and single-speed
- Design
- Laser-cut, 3-point contact drop-in gauge
- MPN
- CC-4.2
Good questions
Get to know Park Tool
There's more to Park Tool than this one product. Our Park Tool page has the full Park Tool lineup we carry and more about the brand.
Visit the Park Tool page →What do the 0.5, 0.75, and 1.0 percent wear readings mean?
Park Tool recommends replacing 11 to 13-speed chains at or just before 0.5% wear, 5 to 10-speed chains at or just before 0.75%, and single-speed chains at or just before 1.0%. Some drivetrain manufacturers set their own limits, so check yours. Going past those points means the chain starts wearing your cassette and chainrings too.
What chain speeds is the CC-4.2 compatible with?
The CC-4.2 is compatible with 5 through 13-speed derailleur chains and single-speed chains. It works across road, gravel, mountain bike, and commuter drivetrains.
How often should I check my chain wear?
Chain wear is cumulative and accelerates as mileage increases. Most mechanics recommend checking every 300 to 500 miles or at every service. High-mileage riders, wet condition riders, and those running 12-speed drivetrains should check more frequently.
What riders say about the Park Tool CC-4.2 Chain Checker Tool
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