Tool Dynamic Dynamic Double Checker

The Double Checker is a precise, pocket-sized, laser-cut tool for checking chain wear and brake rotor thickness. It has an integrated chain hook to keep the chain stable during installation, as well as a ruler for quick measurements.

Riding with a worn chain or brake rotors that are too thin can result in a broken chain, unreliable braking and faster wear of the drivetrain.

The tool’s brake rotor measuring slots are marked with the brand names SRAM, Shimano, Campagnolo, Hope and Magura.

Checking chain and brake rotor wear helps assess the condition of bicycle components and their safety. A worn chain runs less efficiently, can affect the durability of the entire drivetrain and is more likely to break. Brake rotors that are too thin provide significantly less braking power than new rotors, so inefficient and unreliable braking can create dangerous situations.

The Dynamic Double Checker is suitable for all 7–13-speed chains, including SRAM Flattop, Shimano and Campagnolo chains.