Review on Park Tool Chain Checker CC 4 by John Warren

This is a good tool, easy to use and durable. As most of you reading this know, it is important to replace your chain as it is exceeding its tolerances. This usually happens after around 2000 miles, but your results may vary depending on riding conditions and how often you clean and lubricate the chain. If the chain is not maintained and replaced, it will damage the rear cassette and sprockets, which are quite expensive to replace. Parking sensors are expensive, but you should use this sensor for a lifetime, so give yourself a little money.