Wolf Tooth 40T GC Cog for Shimano
You asked for it, so WTC made it -- the Wolf Tooth GC is now available in a slightly smaller size! Most of the low gearing from its big brother with improved shifting in the smaller cassette cogs. This cog is made with the precision and finish our customers have come to expect from WTC.
This cassette sprocket is for use only with Shimano brand 10spd XT & XTR cassettes. It is NOT compatible with any other brand or model of cassette. The shift points are properly timed to the tooth locations on the 36t Shimano cogs for optimal shifting performance.
Use of this cassette sprocket requires removal of the 17T cog & spacer from your cassette.
A longer (25mm) “B-screw” on the rear derailleur isn't needed in most cases. If you do need a longer B-screw to get the correct amount of clearance, you can order them directly from WTC or go to your local hardware store and pick up an M4 x 25 socket head cap screw.
You may need a longer chain that what is presently on your bike. Make sure that when shifted to the 42T cog, there is still some amount of forward travel possible with the rear derailleur cage. This is especially important on bikes with rear suspension. WTC has tested with Shimano, KMC & SRAM chains – all function well.