Shimano XTR FD-M986 Dyna-Sys Traditional Front Derailleur - Double $109.95
Flawless Front Shifting
We grew up with derailleurs that looked a lot like this one, save for the sleek, new style of XTR 980. This XTR Dyna-Sys Traditional Double Front Derailleur FD-M986 has a traditional design. Some might call it a high clamp, some a bottom swing. Either way, some frames require it because of the seat tube shape or geometry, and we've always known traditional XTR derailleurs to offer supreme function and long-term durability.
Shimano builds this derailleur to be used with the XTR Race Double Crankset and XTR 10-speed HG-X chain. So while it could be used with a triple, it wouldn't be optimal. The cage is specifically shaped to meet the needs of the double. Even though it also will accommodate a maximum chainring size of 42 teeth, the cage is shorter than the triple version. This means that if you paired it with the triple crankset, in the 24t little ring your chain would drag across the bridge of the cage when you were in most cogs in back.
The Shimano XTR Traditional Double Front Derailleur FD-M986 has a multi-clamp design that allows it to be used with seat tubes in any one of three different diameters -- 28.6, 31.8, and 34.9mm. A plastic shim is used to accommodate the two smaller sizes. The lever arm is compatibility with top- or bottom- pull cable routing. The limit screws are angled outward to facilitate adjustment for convoluted rear suspension designs as well.