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 so always select the correct type for the cassette brand you have.
- Compatible with SRAM 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
- These older rear derailleurs do work with the GC40.
- Can be run in 2x configuration with a long cage rear derailleur
- These may fit tightly on some over-sized hub bodies such as Stan's No Tubes 3.30 and the Easton X4 hubs. With a little filing and some grease they will go on.