Rohloff HG-Check
Cog wear indicator for HG sprockets

Rohloff developed the HG-Check tool to be able to quickly determine the condition of Shimano HG cassette sprockets. The tool will indicate when the cogs are on the verge of being too worn out, therefore preventing chain skipping.

Cassette cogs should be checked before long trips or before replacing a chain to determine if the new chain will skip on the old cogs.