A worn bicycle chain can cause poor shifting and in time can even cause
excessive wear to the derailleur and rear cogs, causing a much more
expensive problem. That's why bike component manufacturers recommend
chain replacement at regular wear intervals. Now you can quickly and
accurately determine the wear (or "stretch") of nearly any bike chain
with the CC-2 Chain Checker.
Simply insert the Chain Checkers pins into two links, lightly press
the swing arm gauge, and then check the gauge window for an accurate
reading. The CC-2 is compatible with most single-speed and derailleur
chains*, including Shimano® XTR® 12-speed chains.
5-to-10 speed chains: replace chain at or just before 0.75%
11-to-12 speed chains*: replace at or just before 0.5%
Single-speed chains: replace at or just before 1%
Check with manufacturer for specific replacement instructions