The Shimano XTR RD-M9000 rear derailleur is the pinnacle of mountain bike rear derailleur design. Its sculpted form could be easily placed in an art museum but is really a product of years of refinement geared toward the ultimate in shifting performance on all frame types from hardtail to full suspension plus more durability and of course low weight.

This effort is even more low profile the previous Shadow Plus derailleurs meaning it is less likely to catch brush, sticks or rocks on a tight trail than can sometimes lead to disaster. The clutch lever has been moved with the clutch position pointing down for more room/better compatibility on some frames. Speaking of the clutch, it is now more easily adjusted externally with just an Allen wrench. This make is easier to tune - adding more tension for bumpy, rough trails and reducing chain tension for a lighter shifting action on less gnarly terrain.

Shimano has tweaked the derailleur geometry in terms of an improved slant angle so the chain sits closer to all the cassette cogs through the entire 11-40 ratio. Chain/cog engagement is further enhanced by moving the upper guide pulley forward. The big benefit here is no ghost shifting on full suspensions - even on the super steep stuff.

Select the GS medium cage version for single/double setups and the SGS long cage for use with triple cranks.