The rear derailleur: It's the first place most eyes dart when scoping out a new ride. It is the waving flag that signals to the world the machine's degree of mechanical supremacy. And, in the case of the all-new Shimano XTR RD-M9000 XTR Rear Derailleur, the statement doesn't get much more clear: it's the heart of a serious drivetrain.
As per the rest of the new XTR 9000-series parts, Shimano scrutinized the last-gen bits top-to-bottom and thoroughly refined everywhere it could. The rear derailleur sees an already low-profile shadow design get even lower-profile that's a claimed 30mm narrower than the previous design, keeping the derailleur that much further out of harm's way. The slant angle of the derailleur has been fine tuned to improve shifting smoothness and reduce ghost-shifting that results from suspension movements. Both of these areas of performance were also addressed in the moving of the top pulley wheel further forward, increasing chain wrap around the cassette and reducing chain slap against the chainstay, as well.
The M9000 rear derailleur also now has an externally adjustable clutch to alter the degree of chain slack you'll permit. In its most open setting, the chain is slack and shifting effort is very low, which is fine for smooth terrain, but less so for the rough stuff. When the clutch is in its most stable setting, shifting effort is higher but the chain is far more stable, great for when rough terrain is on the menu, keeping the ride quieter, shifting more precise, and reducing the chances of dropping the chain. To that end, the derailleur's return spring has been strengthened for quicker shifting action, and refined seals, bearings, and a carbon fiber pulley cage all serve to reduce overall weight and make shifting more precise, since the less weight is being thrown around laterally as you shift, the more easier that weight is for the mechanism to control.
The Shimano RD-M9000 XTR Rear Derailleur comes in Long Cage or Medium Cage versions and is designed specifically for use with the new CS-M9000 11-speed cassette and SIL-TEC chain.
- Increased capacity over previous versions
- 11-speed design
- 40-tooth maximum cog size
- Long and Medium cage options