Unless you're a brute who rides singlespeeds just to make a point, a rear derailleur is a necessary evil you can't ride without it, but damn, it can be a pain to ride with it. Not so with Shimano's XT Shadow Plus RD M786 Rear Derailleur. The most recent offering in Shimano's Shadow line, the XT Plus features the new direct mount system, which reduces flex, wear, and weight, and makes for easier wheel changes with modern thru axles. There's also less cable wandering, which reduces the amount of cable in the system and helps with cleaner, crispers shifting. Don't worry if you're riding an older frame, either the XT Plus also comes with a traditional link, if your frame isn't set up for direct mounting. The other key feature of the XT Plus is the so called chain clutch, which can be engaged to increase spring tension in the derailleur to help eliminate dropped chains and cringe inducing chain slap. The whole derailleur is built from durable aluminum, so it isn't the lightest weight weenie option, but it's perfect for hard riding in tough terrain. There's a little bit of extra tech we should cover, too. The XT Pro is available with two cage lengths, Long SGS and Mid GS. The length of the cage determines the overall chainwrap capacity how much slack your derailleur can take up, basically or how big of a tooth difference it can accommodate between the biggest gear and the smallest gear. Total difference can be found with this equation: big chainring minus small chainring, plus largest cog minus smallest cog. The Long SGS option will work with just about any setup, but the Mid GS will only work with certain setups, so check before you buy if you're looking to go shorter.