That derailleur, rear mech or dangly thing that hangs off the back of your right hand chain-stay has been around since the early 1900’s. And for the most part, it’s remained relatively unchanged. Endless refinements to the leverage action and an ever increasing number of sprockets on the cassette have been a given, however the humble braided steel cable has been in some ways its Achilles heel. Subject to grit, tight routing, outer housing compression and constant maintenance, it’s survived mainly through its ease of replacement, cost and light weight. That said, there has been attempts to drop the cable. Shimano’s infamous pneumatic Airlines being the most notable, however the electronically controlled mech has always been the Holy Grail. Mavic’s ill fated Zap system in the early 90’s tried hard but succumbed to water and grit problems, so it wasn’t until 2014, and the introduction of Shimano’s Di2 system on the XTR groups that electric was truly proven ready to play in the dirt. As has been the way eternally, Shimano tech trickles down to the more affordable groupsets, and finally the trail riders amongst us not ready to shell out for XTR Di2 can look very closely at the newly launched XT Di2 drivetrain.
Possibly the key feature on the groups is the Bluetooth-equipped processor that offers riders the ability to wirelessly set up their drivetrains. The bar mounted display is not only a three-port E-Tube hub, its readout displays the core info like which gear you’re in and battery life which will keep you entertained when not focused on the trail.
Wireless connectivity is a huge step up over the XTR release, meaning the system’s tune-ability and user-friendliness is off the charts, especially if you happen to use iOS. The new brain and battery sync wirelessly via Bluetooth to a phone or tablet-based app. The app is available for both Android and iOS; the tablet version has more options. Riders can use the app to tune the speed of multi-shift, to shift multiple gears with one long press of a shifter paddle along with switch the system from manual to syncro shift, where the system responds to the rider’s shift by automatically selecting the chainring and cog that offer the best chain line for the desired gear size (that’s if you’re running a 2x set up of course). Riders can even program a shifter to control CTD suspension settings on electronic-equipped Fox shocks and suspension forks which is pretty damn cool!
Perhaps the best feature is to current Di2 owners, as if you shelled out for XTR you’d be feeling a little screwed that your premium groups wasn’t Bluetooth compatible. But any current Di2 component is cross-compatible within the E-Tube system, the new brain and batteries will work for both road and mountain drivetrains. The system also gets the D-Fly communication, a private ANT+ system that allows for displaying battery life and gearing on third-party cycling computers so you can get your watts and training going on big time.
Coming in 1×11 and 2×11 set ups, with a cassette range of up to 11-46 teeth on the 1x setups, Shimano have released a truly trail aimed groupset. Shift paddles on the triggers are slightly bigger than those of XTR. Otherwise, the system is basically XTR, with some material changes for cost savings as per the trickle down. Thanks to the never ending progression of technology, the motors in the XT Di2 mechs are twice as powerful as those found on Shimano’s road groups, meaning dialed shifting in the grimiest conditions you can imagine. Yep, it’s fully sealed and waterproof, and if your rear end has messy routing, say goodbye to ghost shifting.