18 Tooth Cog Replacement for Shimano 11-speed


Replacement cog for 11-speed Shimano cassettes.

  • Remove the 17 and 19t cogs and replace them with the 18t for GC49 conversions.
  • Installation instructions on the GC tech page.
  • These are specifically designed for use with Shimano cassettes.  The clocking, or rotational orientation, between SRAM and Shimano cassettes is much different so optimal shifting cannot be achieved unless the design is optimized for each separately.
  • Design and manufactured in Minneapolis, MN USA



Shimano 11 speed cassettes

  • SLX 11-42t (CS-M7000)
  • XT 11-40,42,46t (CS-M8000)
  • XTR 11-40t (CS-M9000)


    Tech Specs:

    • Material: nickle plated steel with laser marking
    • The cog is 1.6mm thick and weighs 22g
    • Colors- Silver