The easiest way to determine if you need a new bike chain is by doing a pull test. First, pull your bike chain at the front of the chainring where it’s wrapped around the crankset. If the chain lifts off at the top or bottom where it sits on the teeth of the chainring, this means the chain has lengthened and no longer sits in the chainring teeth properly. Lifting is a telltale sign that the chain is beginning to wear and will need replacement soon.