With special considerations for safety, it is vital that you know when to replace a bike chain.
Your chain transfers force to the rear wheel, ensures smooth shifting and maximizes your pedaling power. A new chain is one of the cheapest upgrades you can do to your bike to make it run as smooth as the day you bought it. For this reason, you may prefer to replace your bike chain frequently.
At the other end of the spectrum, you may just be an average rider who only takes their bike out on the weekends. In this case, you can probably get away with only replacing your bike chain when you notice signs of wear.
For every rider, you should change you bike chain as soon as you start to notice signs of wear.
A failing bike chain can cause problems such as bad shifting and costly repairs, like worn teeth on your cassette and chainring. Worse than that, your chain can break completely, leaving you stranded and possibly hurt.