Shimano officially announces M9050, an electronic shift system for their flagship offroad component group, XTR M9000. In many ways, this is one of the least surprising announcements since SRAM went to 11-speed for the new Red group a couple years ago. Shimano’s Di2 concept has been highly successful in the company’s road offerings, so of course they’d like to bring that to the dirty demographic. One tip-off I noticed was when I downloaded the PC program for the Di2 diagnostic tool for customizing Di2 road systems, and the menu options included road bike, city bike (for the Di2 Alfine internally geared hub system), and mountainbike….hmmmmmmm. But even if we knew it was coming, XTR Di2 could have even greater potential than electronic shifting on the road. Let’s cut to the chase: what’s most impressive about M9050 is the option of using just one shifter to handle 2x11 or 3x11 drivetrains. You shift up or down on the buttons, and the SYNCHRO SHIFT system automatically shifts a sequential pattern.
When using a single shifter in either a 2x11 or 3x11 drivetrain, Synchro Shift will shift front and back derailleurs in order to give you a sequential progression of gearing. You don’t have to think about it, it just does it for you. This could only work because Shimano’s electronic front derailleur and chainring designs are indisputably the best, such that front shifts occur with practically the same speed and conviction as the rear. Still, it’s not hard to imagine a situation on a trail when an unexpected front shift might upset your groove. Synchro Shift incorporates an audible signal that indicates that a front shift is imminent, but it also offers on-the-fly choice of two presets for the sequence of chainring/cog combinations (what Shimano refers to as a shifting “map”) to suit your riding style or the immediate terrain. The presets are can be reprogrammed with Shimano’s Di2 diagnostic tool. You can even program the drivetrain to skip specific combinations, such as a big ring/big cog combo, which would be a good if, for example, your long travel rear threatens to exceed the capacity of your derailleur.
The idea of sequential shifting has been around for a while, and in fact some people have already hacked road Di2 systems to the same effect. However, I can’t see road racers en masse leaping on that idea in the near future. That’s because despite all the carbon frames, additional cogs, and threat of disc brakes, for road bikes wheel size, frame geometry, and the roads themselves haven’t changed much in 50 to 60 years of road racing. When old school racers talk about attacking in a 53 x 12, the younger generations understand. Meanwhile for mountainbikes the past 15 years have been a maelstrom of crank and wheel size developments; plus different genres of offroad riding keep cropping up (eg, enduro). So for road racers, ring/cog combinations are automatically referenced through the conventions of road bike tech and long hours in the saddle, whereas mtn bikers have no traditions for equipment configuration and their riding styles are characteristically dynamic. Why not just ride and let the microprocessors do the thinking for you? Shimano’s design focus is on the rider’s “flow”, via components that allow the rider to ride the trail instead of riding a bike on a trail. Of course, if turning over the destiny of your gear selections to an electronic intelligence fills you with apprehension, you can breathe easy knowing that you can switch to full manual shifting if you have installed two shifters (or just the one if you are running 1x11).