Double checker

The Double Checker is a pocket-sized, laser-cut precision tool to accurately check chain wear and rotor thickness. It features a built-in chain hook to keep the chain steady during installation and a ruler for quick measurements. Riding with a worn chain and rotors that are too thin can lead to the chain snapping, unreliable braking performance and overall increased wear of your drivetrain. With the Double Checker, you know exactly when you need to replace your chain and rotors to stay safe and fast while prolonging the life of your gear.

The three-point design is made to measure true pin wear, eliminating the effect of roller wear. This means you know precisely how worn your chain is. The rotor slots are labeled for use on brand-specific rotors, such as SRAM, Shimano, Campagnolo, Hope, and Magura.

Made for all 7-13-speed chains, including SRAM Flattop chains, Shimano and Campagnolo.
Exact rotor-thickness readings with brand-specific measurement slots: SRAM, Shimano, Campagnolo, Magura, and Hope.
Anodized aluminum is light, strong and Dynamic purple.
Guidelines displayed on the tool, no need for a handbook!
Clever chain hook makes chain handling quick, easy and safe.