XTR M9100 GS Rear Derailleur (Blem)

XTR M9100 GS Rear Derailleur (Blem)

IRDM9100GS Blem

Regular price $279.99 Sale price$237.77 Save 15%

Free shipping on all orders over $49. $9 shipping for orders under $49.

Cannondale, Santa Cruz, Cervelo, Gazelle, BMC, and *other bikes ship for FREE, but Gold Label Assembly will be added at checkout for only $79 (reg. $100) to cover the professional bike build and re-packaging by our certified technicians. It’s bike shop quality, direct to your door!

Some bikes not eligible for shipping due to manufacturer restrictions.

Shop with confidence! It's important to us that you are happy with your Mike’s Bikes purchase so we offer offer a 30-day return/exchange window for your unused gear and 14 days on all bikes. Our exchange and return process is fast and easy. If you choose to exchange for a different size or color, we will ship your product for free.

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This item is sold as-is.

Our Online Warehouse Sale features sample bikes, slightly used test ride & photoshoot bikes, bikes with slight cosmetic blemishes, and one-off custom builds.  

There could be blemishes or dents. All bikes are inspected by one of our expert mechanics before shipment. This item is sold as-Is and no exchanges/returns will be accepted under any circumstances.


  • No packaging


The XTR M9100 series of derailleurs brings a new level of drivetrain silence thank to decreased tension in the low gear position and an added bumper on the pulley cage. Larger 13T pulleys increase efficiency and chain management while compatibility with SHIMANO's new 12-speed cassettes boosts range.


  • Decreased tension at low gear position to prevent high chain tension
  • Bigger 13T pulleys 
  • Shadow Plus clutch reduces chain slap 


  • Speed: 1 x 12 Speed
  • Shifter Compatibility: Shimano Mountain (12 Speed)
  • Shift Mechanism: Cable Actuated
  • Max. Tooth: 45T (Medium Cage)
  • Min. Tooth: 10T
  • Chain Wrap Capacity: 35T (Medium Cage)
  • Cage Material: Carbon/Aluminum
  • Chain Retention: Shadow Plus
  • Weight: 237g (Medium Cage)