Now that 11-speed Shimano is hitting the masses with XT and later this year SLX, Wolf Tooth is offering a solution for those looking to increase the range of their cassette. The most common application is a 1x drivetrain, but the GC45 can be used with a 2x drivetrain and a long cage (SGS) rear derailleur.

Just like our 10-speed GCs, this cassette extender was engineered with a no compromises approach to shifting quality and longevity. The stiffness of the new GC45 along perfect clocking (rotational orientation) and wider chain driving bearing surfaces (when compared to other options available) make for a factory perfect shifting experience that will last. Also included with the GC45 is a 18 tooth replacement smaller cog and spacer for smooth cassette transitions.


Here is what the cassettes looks like after a GC45 Conversion.

11-40: 11-13-15-18-21-24-27-31-35-40-45

  • Weight (XTR) = 412 Weight (XT) = 490
  • Total range increases from 364% to 409%

11-42: 11-13-15-18-21-24-28-32-37-42-45

  • Weight = 510
  • Total range increases form 382% to 409%


The GC45 is manufactured in our new manufacturing facility in Savage (yes, Wolf Tooth lives in Savage) Minnesota. Other Tech specs:

  • MSRP 89.95
  • GC45, 18t replacement cog, and spacer for 18t cog included
  • Goatlink 11 is not required but provides improvement in free-chain length (shifting crispness), bringing free chain length back to better than with an 11-42 cassette. [see attached image for this in chart form or the chart and a table can be found on the Goatlink 11 product page]
  • Material 7075-T6
  • Weight - 98g
  • Colours - black & red now with blue & silver to follow in the coming 4 weeks, and possibly a few more colors after that.

Available for sale now at and at our dealers and distributors in the coming weeks.