Shimano XTR RD-M9100-SGS 12-Speed Long Cage Rear Derailleur (51T Max)
IRDM9100SGS
SKU code: SHM-IRDM9100SGS
In Stock
The Shimano XTR RD-M9100-SGS is Shimano's flagship 12-speed mountain bike rear derailleur, engineered for riders who demand precise, silent shifting across the widest possible gear range. Its long SGS cage handles cassettes up to 51 teeth, making it the go-to choice for technical trail riding where maximum range and chain stability are non-negotiable.
Highlights
- Shadow+ stabiliser clutch locks the pulley cage to eliminate chain slap on rough terrain
- Long SGS cage supports 10-51T cassettes — 41T total wrap capacity
- Oversized 13T guide pulley reduces friction and improves chain engagement
- Reduced spring tension in low gear prevents excess chain friction and noise
- Bumper on pulley cage cushions chain contact for a quieter ride
- Carbon fibre outer cage keeps weight to 240g without sacrificing rigidity
- Eight fluorine-coated pivot bushings for smooth, precise cage movement
- Sealed bearings on both guide and tension pulleys for long service life
Shadow+ Technology
Shimano's Shadow+ damping system uses a stabiliser with an on/off switch to resist unintended pulley cage movement. On rough descents or technical singletrack, this locks out chain slap and dramatically reduces the risk of chain drop — without forcing you to use a separate chain guide. The switch lets you disable the clutch for easier wheel removal when needed.
XTR-Grade Construction
The outer cage is moulded from carbon fibre reinforced polymer (CFRP), while the inner cage uses aluminium — balancing weight savings with the structural rigidity needed to handle the leverage of a 51-tooth low cog. Eight fluorine-coated pivot bushings reduce internal friction across the full range of cage movement, contributing to crisp, consistent shifting over thousands of kilometres.
Compatibility & Fit
Designed specifically for 1×12 mountain drivetrains. Compatible with Shimano 12-speed HG+ cassettes including CS-M9100, CS-M9101, CS-M8100, CS-M7100, and CS-M6100. Works with Shimano 12-speed HG+ chains (CN-M9100, CN-M8100, CN-M7100, CN-M6100) and shifters from SL-M6100 through SL-M9100. Mounts to a standard derailleur hanger (direct attachment). Not compatible with Shimano's older 11-speed or SRAM drivetrains.
Shimano components are covered by a 2-year warranty against defects in materials and workmanship from the date of purchase. This warranty does not cover normal wear, crash damage, or improper installation or use. For warranty support, return the item to Tune Cycles.
- Shadow+ clutch stabiliser with on/off switch — reduces chain slap and drop on rough terrain
- Long cage (SGS) — supports 10-51T cassettes
- 41T total chain wrap capacity
- Oversized 13T guide pulley for reduced friction
- Reduced derailleur tension in low gear — lowers chain friction and noise
- Pulley cage bumper minimises chain noise
- Carbon fibre reinforced polymer (CFRP) outer cage
| Speed | 12-speed |
|---|---|
| Cage length | Long (SGS) |
| Maximum cog | 51T |
| Minimum cog | 10T |
| Total capacity | 41T |
| Guide pulley | 13T, sealed bearing |
| Tension pulley | Sealed bearing |
| Outer cage material | Carbon fibre (CFRP) |
| Inner cage material | Aluminium |
| Pivot bushings | 8 × fluorine-coated |
| Weight | 240g |
| Mount type | Direct attachment (standard hanger) |
| Drivetrain compatibility | 1×12 Shimano HG+ |
| Colour | Grey |
| Part number | IRDM9100SGS |
| SKU | SHM-IRDM9100SGS |
| Barcode # | 4524667880257 |
| Brand | Shimano |
| Shipping Weight | 0.3000kg |
| Shipping Cubic | 0.001000000m3 |
| Unit Of Measure | each |
Must be installed and serviced by qualified bicycle mechanic
