SRAM X9 Rear Derailleur
With it's Aluminum alloy links and forged B-knuckle construction, the X9 derailleur is a tough little nugget that draws on X0 technology for sweet shifting performance. Having come a long way from the original X9 trigger shifters and rear derailleur, the latest model is much more refined with a stiffer construction and smooth Exact Actuation cable pull. The X9 is available in short, medium and long cage versions so you can choose the right option for your drivetrain; the Short cage suits single chainring setups, Medium cage is for double cranksets and the Long cage works with the standard 3x9 arrangement. Due to the Exact Actuation 1:1 cable pull, you can only use the X9 rear derailleur with SRAM 9 speed trigger or grip shifters, but it is compatible with both SRAm & Shimano chains and cassettes.

Slick shifting and low weight has always been paramount to the SRAM X9 groupset, and the latest incarnation continues to drop unnecessary material whilst building on the reputation of durability that is synonymous with mountain bike SRAM Components. A high-end bike is nothing without high-end components and even something as simple as a worn cassette can make the difference between mis-shifting or powering past your mate on that steep climb. Every SRAM derailleur and shifter features the R&D and trickle-down technology that has come from the incredible XX groupset, giving you impressive shifting without the exotic materials. We won't get into the whole SRAM vs Shimano debate, though we will recommend sticking with the one brand for driveline components for optimum performance (eg; using SRAM cassettes with SRAM Chains). You will find that SRAM shifting is very positive and solid regardless of the conditions, and will give you many miles of dependable service.

From SRAM:

"The X.9 utilizes SRAM's famous shifting technology in a super-light, slim chassis. The X.9 sets the standard for performance, weight, materials and good looks."