Lumintrail Bicycle Chain Wear Indicator Bike Chain Checker Gauge

This simple tool makes it easy to know when your chain is ready to be replaced. Over time the internal components of the chain including the rollers and rivets begin to wear down giving the appearance that the chain is stretching. This wear can cause the chain to mesh poorly with the cogs. The high quality durable Lumintrail chain wear gauge features permanent measurement markings for 0.75% and 1.0%. Directions Place the long hook end of the tool into the chain links. Then try and fit the other two pronged end into the links. If the gauge fits into the links flush, then replacement of the chain may be necessary due to wear. A good rule of thumb is that if you have a bike with 10 or fewer gears you should replace the chain is wear is at or above 0.75%, If you have a bike with 11 or more gears replace the chain when the wear is at or above 0.50% and with bikes with two sprockets replace the chain when wear is at or above 1%. Specifications Size: approx. 5.53 x 1.875 inches (L x W) Weight: 1.4oz