The Connex chainring wear indicator allows you to check whether you need to replace your chainring (or sprocket) to protect your chain. It is fast and simple to use and compatible with all standard geared drive chainrings and sprockets.
If the wear indicator does not fully fit into the gap between two teeth and a small gap remains visible, the gearing is still in a good condition. If the indicator is completely in contact and there is no gap, the sprocket/chainring should be replaced together with the chain.
Independent reviews:
Connex Chainring Wear Indicator
