SRAM X9 Type 2.1 Rear Derailleur

The SRAM X9 Type 2. 1 Rear Derailleur takes the revised Type 2 design and makes some minor changes like upgraded bearing seals and a tiny reduction of weight. Otherwise, it's the same Type 2 goodness that countless riders have bolted onto their machines for the better. SRAM's Type 2 derailleur technology differs from its competition in a key way. Rather than opting for an adjustable friction band, SRAM put a Roller Bearing Clutch in its Type 2 derailleurs. The clutch comes pre-set from the factory to provide a certain amount of friction inside the derailleur cage pivot. This friction keeps the cage from bouncing up and down over rocky trails and de-tensioning the chain. Because it's pre-set at the factory, SRAM's Type 2 clutch can't be disengaged or adjusted like Shimano's Shadow Plus mechanism. That being said, the Type 2 clutch is self-lubricating, and there are no external moving parts, so unlike the Shadow Plus system, it's designed to be maintenance-free. The Type 2 mechanism adds about 30 grams to the weight of a standard X9 rear derailleur. A unique feature of the Type 2 system is that its Cage Lock technology allows you, with the push of a button, to lock the derailleur cage in an extended position. This is a nice feature that allows for easier-than-ever rear wheel installation. There's no need to worry if you accidentally leave the derailleur cage locked; it will return to normal operating position when you hit your first bump. Another benefit of the Cage Lock is that it makes chain installation a bit easier; you don't have to maintain a consistent pulling force on the cage while joining the two chain ends.