Wolf Tooth 42T GC Cog For Shimano

The product that set the standard and still the best available! The GC line of cassette extender cogs allow you to modify your 10 speed cassette into a wide range cassette. To achieve the optimal shifting, the GCs are optimized for Shimano or SRAM cassette — always select the correct type for the brand of cassette you have.

Compatibility:
– Compatible with Shimano 10 speed cassettes listed on the GC tech page
– Compatible with all 10 speed chains
– Note that you may need a longer chain that you currently have on your bike
– Chain stretch should be less than .5 when installing a new GC
– Compatible with all 10 speed rear derailleurs except non-clutch type SRAM rear derailleurs model year 2012 and older
– Can be run in 2x configuration with a long cage rear derailleur