No shift! Well, easier shifting anyway. After years of speculation and rumor, Shimano has announced the imminent release of its much-anticipated XTR M9050 Di2 electronic shifting system for mountain bikes, in 1x, 2x and 3×11 configurations. The system is expected to arrive at retail by the fourth quarter of 2014.
Exact dates for retail availability have not yet been released, and specific pricing information is available yet either. Shimano hints that the cost could be similar to the difference in the road groups, which is about 40 percent higher for the full 2×11 electronic system.
The new XTR Di2 system consists of electronic shifters, derailleurs and rechargeable battery, and works with the new XTR 11-speed components—there are even two shifting modes that allow for fully manual or electronic front derailleur shifts. It will be available for 1x, 2x and 3x configurations. Current 11-speed XTR users will be able to retrofit their systems. The system is also compatible with new FOX electronic suspension adjustment.
“Di2 digital shifting is seamless, instantaneous and can be custom tailored for any rider,” according to the Shimano press release. “Shifting becomes a simple rider reflex, allowing riders to place their attention where it belongs—on the trail ahead. Totally new ergonomics reduce hand movement and improve control, further boosting rider confidence.”
The new 9050 rear derailleur features the Shimano Shadow RD+ Stabilization system, which takes the previous chain retention lever—designed to hold the chain in place on bumpier terrain and allow for easier wheel removal when switched off—and adds an adjustability function. A simple bolt adjusts the tension to suit rider preference. The new Firebolt shifters feature programmable shift modes—for single and multiple shifts—and a new ergonomic design for easier, more natural feel, according to Shimano. Riders can personalize shifting on the programmable shifters: how many shifts to execute when button is held down, and how quickly these shifts are made.
Also included in the system, and borrowed from the road group, is the Di2 Display Unit for monitoring the system. This includes digital gear readout, along with battery level, shifting mode, and FOX position (climb or descend).
For those still unfamiliar with electronic shifting, the system allows battery-powered front and rear derailleurs to automatically shift at the press of a button mounted to the handlebars, which takes the place of traditional shift levers. The benefit is that it takes less energy for the rider to engage a shift. And according to Shimano, the shifting is quicker, more precise and requires less adjustment after proper initial setup.
They maintain those benefits are also true with the MTB version, and they’ve added an even more appealing option to MTB riders. While offered in a traditional right-and-left-shifter configuration, the available Synchronized Shift mode combines front and rear shifting into one right-handed shifter that can engage both derailleurs. This means no need for a shifter on the other side saving weight and, suggests Shimano, resulting in more intuitive shifting.
In standard two-shifter operation the rider shifts exactly like they have with mechanical systems, only with a press of a button instead of the push of a lever. But in Synchronization Shift mode, the rider only mounts the single shifter, and all shifting is controlled by this unit. Furthermore, in the 2x or 3x systems, it will automatically detect the best configuration between front and rear derailleur so the rider won’t have to do the often-awkward double shifts before a steep rock garden, for instance. The computer chooses the best combination with the least “jump” in ratio for a smoother transition.
This option is also programmable, so riders can choose between two existing “shift maps” to best suit their riding styles. It is possible to switch maps on-the-fly, but personalizing those maps must be done on a computer. But on the trail, the system will give an audible signal to warn the rider before a computer-initiated front shift, but with the push of a button the rider can override the shift and remain in the same ring if preferred.
Added weight will not be an issue, according to Shimano—in fact some weights will actually drop with the electronic system. For instance XTR Di2 with a 2x setup and only a right hand shifter (Synchronization mode), the new M9050 has the same total weight as the M9000 which is the current XTR mechanical group. The electronic version is 47g without the wiring, but the Di2’s wires are lighter than traditional cables, so it evens out.
Part for part the weights are also similar: At 289g the Di2 rear derailleur, for instance, is 68g heavier than its mechanical counterpart. But the Di2 front derailleur comes in at 115g, lighter than the mechanical by about 5g.
Shimano originally launched electronic shifting for road use on its Dura-Ace group over five years ago—to equal parts excitement and skepticism—but while there have been minor issues, the system has since gained the respect and admiration of most in the industry for its precise, immediate actuation with minimal rider effort.
Most assumed an MTB version would soon follow, but there was even more question about how it would work in the rigorous, bumpy conditions of trail riding. Shimano addressed that over the last five years with over 20,000km of testing, and they’re ready to launch.
As for the usual speculation that accompanies product launches like this, Shimano will not comment on the possibility of an XT version (the next step down on their group hierarchy) to follow. Nor will they say if a wireless version is in the works—only to tease with, “What the future will bring regarding new products (even competitors’) time will tell.”