Technical Information about the Wear and the Replacement of Standard Chains 1/2" x 3/32"
Any chain becomes longer due to wear. Because of constructional reasons, this only effects the pitch of the pin link plate so that the pitch of the chain changes due to wear: the originally identical distances between the rollers change into the so called S-O-S pitch, long-short-long-short.
The stretching of the chain and the inhomogeneous pitch result in increased wear of the sprockets and chainrings. In principle, one can use a chain as long as the chain does not spring. Normally, chains are replaced before that moment because a worn chain does not shift very well.
In case of relatively cheap sprockets and chain rings and normal riding conditions one can use the chain as long as it words well. If you replace the chain you then replace sprockets and chain rings as well.
If expensive sprockets and chain rings are used, the chain should be replaced before it starts to damage the sprockets and chain rings due to excessive wear. Furthermore, we recommend to use a Rohloff S-L-T 99 chain because it wears sprockets and chain rings less due to its constructional advantages.
How can you check when your chain should be replaced? The standard formula is that your chain should be replaced when it has been stretched more than 0.1mm per link. With the chain wear indicator Rohloff Caliber 2 you can check with one glance whether it is time to replace the chain by hooking it between the rollers of the chain. With two different gauges you can adjust your checking to the type of sprockets you use. If you use aluminium sprockets, you should replace the chain even before the stretching of 0.1mm per link. Problems of the power transmission are not always caused by the chain. Modern sprockets with low and thin teeth and mass production of low quality material are just two reasons, why sprockets can be damaged even before the chains in worn.
In order to check the wear of sprockets, Rohloff has developed the HG-IG-sprocket wear indicator Rohloff HG-Check. Without a tool it is nearly impossible to spot the wear of HG and IG sprockets so that very often the sprockets are replaced with the chain.
With the Rohloff HG-Check it becomes possible to check the sprockets which gives a clear answer whether it is necessary to replace them or not. Therefore, this inexpensive tool should be found in all workshops.