The latest hardware from SRAM and Shimano offer more precise shifting with reduced weight and modern materials. The rear derailleur serves double duty: moving the chain between rear sprockets and taking up chain slack caused by moving to a smaller sprocket at the rear or a smaller chainring by the front derailleur. In order to accomplish this second task, it is positioned in the path of the bottom, slack portion of chain.
Deore XT rear derailleur delivers reliable and precise shifting with a stiff and lightweight open design All-alloy construction leads to lower weight...