How to use a Park Tool CC-2 Chain Checker
The following information was derived from the Park Tool Company instruction Manuals
A worn bicycle or indoor cycling chain shifts poorly and wears sprockets at an accelerated
rate. The Park Tool Company CC-2 Chain Checker provides a precise measurement of
bicycle and excercise cycle chain wear on most derailleur chains.
1. Set pivoting gauge so ď0Ē is visible in viewing window.
2. Lower the Park Tool CC-2 so fixed pin rests between chainís outer plates
and movable pin rests between the bicycle or indoor cycling chainís inner plates.
3. Lightly push pivoting gauge just until it stops. Forcing the
gauge will damage the CC-2s pins, resulting in inaccurate
measurements. Read number in viewing window. Bicycle and exercise cycle chain re-
placement is generally recommended at .75%, although this
percentage can vary between chain manufacturers. Contact
the manufacturer for specific recommendations.
Because a bicycle or indoor cycling chain must have a small amount of play in the links
to run smoothly, the Park Tool Company CC-2 will show a reading of .25% to .5%
on new chains. This does not mean that the chain is .25% to
.5% worn. It only means there is .25% to .5% play built into the
links of the chain before it starts to wear. No matter what the
reading of a new chain, it should be replaced when the Park Tool CC-2
shows a reading of .75 (or the percentage recommended by
The length of time and amount of riding it takes to wear a
bicycle or indoor cycling chain is determined by several factors, including chain quality,
riding or exercise conditions, and level of maintenance. As a result, chain
life can vary significantly.