KMC - SPROCKET CHECKER
Use the KMC Sprocker Checker as a sprocket wear indicator to assess rear sprocket condition and avoid chain slip on worn sprockets. The rear sprocket should be regularly checked for wear; especially before long rides, races, and before replacing your chain.
Instructions
1. Use with 12 to 21 tooth sprockets. Place the Sprocket Checker chain on sprocket with the bottom round end of the handle between two teeth and the test link angling away from the sprocket.
2. Apply a force of 10kg/22lbs on the handle in the direction of sprocket/drive rotation. While the Spocket Checker chain is under load, swing the test link onto the sprocket.
3. The test link easily moving onto the tooth’s bottom means the sprocket is in good condition.