Shimano XTR Di2 Multi

The rumors are true-XTR will now come in an electronic Di2 version similar to what Shimano has on its high-end road groups.

Shimano released details of a new electronic XTR component group today, officially confirming rumors that have been swirling for months. Just weeks after announcing their mechanical M9000 high-end cross country group's migration to 11-speed shifting, the Japanese juggernaut has introduced a Di2 digital platform for mountain bikes based on the same architecture it developed for road groups over the past five seasons.

XTR M9050 Di2, as it's officially called, consists of digital shift levers, front and rear derailleurs, computer displays and batteries that integrate with elements of the aforementioned M9000 11-speed mechanical group. As with the road groups, electricity and data are transmitted via Shimano's E-tube electronic wiring system. The system can also be configured to control and power FOX's iCD electronic forks and shocks.



Mini primer: Single, multi-shift and Shimano Synchronized Shift explained

‏Without the linear constraints of mechanical systems, Di2 allows riders to configure shifting for manual gear changes in either single- or multi-shift modes, as well as for two custom pre-mapped shift sequences via the Shimano Synchronized Shift programming mode.

‏The manual single- and multi-shift modes are fairly straight forward. Albeit faster, single-shift emulates traditional mechanical shifting, changing gears one at a time with the press of a button. In multi-shift, holding down the button jumps the chain up or down several gears at a time. Shimano says multi-shift can "dump" a whole cassette's worth of gears faster than could be done with mechanical systems.

‏Shimano Synchronized Shifting-Synchro for short-allows users to program custom gear sequences based on personal preferences. For instance, most people try to avoid cross-chaining and avoid using the rear cassette's largest few cogs when they're in the big chainring. With Synchro, mapping can be set to automatically shift into a more-sensible next gear that doesn't cross-chain-say downshifting the front ring while upshift the rear derailleur to the next lowest gear ratio-as the sequential step when they get to that cross-chain gear.

This video helps visualize Synchro Shift and its associated gear ratios for 2x and 3x setups.

‏With the Synchro's two programs, you can set up condition-specific gearing maps-say Synchro #1 for a course with a lot of climbing, and Synchro #2 for a more flat terrain profile. Toggling between the two Synchro programs and manual setting requires a few button presses and can be done on the fly.

‏The system actually emits an audible alarm to foretell impending front shifts which riders can preempt by toggling to manual mode.

‏Using Synchronized Shift only requires one shifter, leaving the other available to control compatible FOX iCD suspension products.

FIREBOLT shifters

‏The aforementioned gear controls-dubbed XTR Di2 FIREBOLT shifters-feature ergonomically developed short-stroke switches that mimic the tactility of their mechanical counterparts, but feature lighter action. Because they don't require mechanical leverage, the radial shifter pods are much smaller than mechanicals and the shifters take up less handlebar real estate. Shimano designed the shifter units to be actuated with either a push-push or push-pull motion.

Complementing the controls is a small head unit plainly called the SC-M9050 Display Unit, which allows monitoring of Di2 data like gear selection, battery level and shift mode. It can also display suspension data for the FOX iCD system, acts as a junction for E-tube wiring, and hosts the system's power input port for charging.

Shimano XTR Di2 Shifters Plus

The XTR Di2 shifters can run gear selection in a number of modes as well as control suspension settings. A head unit display helps you keep tabs with what's going on.

Continue to Page 2 for more on the Shimano XTR Di2 and full photo gallery »

XTR Di2 rear e-railleur

Shimano says its first mountain bike-specific Di2 rear derailleur is also its most technologically
advanced. The RD-M9050 features Shadow RD + stabilization that couples chain control with shift performance that doesn't degrade over time, according to the company. They also promise seamless, instantaneous gear changes, as well as compatibility with any of the 11-speed front chainwheel options-1x, 2x or 3x. The RD-M9050 features Shimano's signature narrow Shadow "q-factor," keeping the mech tucked out of the way of mayhem. It's also available in GS and SGS cage options.

Despite being electronic, the new Di2 rear derailleur retains XTR's jewelry-like finish and form factor.

XTR Di2 front e-railleur

‏The front shifting on Shimano's road groups has a well-earned reputation for speed and precision-characteristics the company says carries over to the dirt side as well in the new FD-M9050 front derailleur. Like the rear mech, the front derailleur is compatible with Shimano Synchronized Shift, and uses computer controlled auto trim as the chain moves up and down the
‏cassette to keep the drivetrain running smoothly.

Shimano XTR Di2 FD

Other than a little extra volume for its motor, the Di2 version XTR front derailleur looks fairly standard. The modular shifter bolts to adapters for any configuration-high clamp, low clamp, e-type or direct.

Power plant

System batteries come with mounts designed to attach to water bottle bosses and nestle the battery next to a bottle cage. Like on the road side, we're likely to see more integrated battery and wire accommodation inside frames and fork steerer tubes as manufacturers adjust frame designs to accept the system.

Shimano XTR Di2 Battery

The XTR Di2 battery attaches to water bottle mounts.

While riders are sure to question the system's robustness, Shimano points out that the road version of Di2 has fared extremely well in the poor weather of cyclocross, the European spring classics and even the winter-like conditions of this year's Giro d'Italia. We at MTBR have also seen hacked versions of Dura Ace Di2 systems on mountain bikes that have proven to be sturdy.

Shimano XTR FAQ

Shimano sent us a handy FAQ that answers some of the questions likely to arise about both the new mechanical and electronic XTR groups.

1: Why did Shimano choose a 11-40 cassette to work with a single chainring setup? The range is too small.
Shimano's philosophy for single front chainrings is that it is developed for dedicated use on specific courses. It doesn't matter if you race enduro or XC, even with a wider range cassette it doesn't cover the range of 2x or 3x. For all-round purposes it is better to choose 2x or 3x. This also results in better durability because the cassette is used more efficiently. We also chose to have all the gear steps below 15-percent so cadence changes are more gradual. This allows the rider to have more control in technical sections.

2. Can I modify the Di2 settings myself or should I go to a dealer?
With your charger for the internal battery you can connect the system to your computer and can change all the settings for the shifter, Synchro modes and multi-shift. Only if diagnostics reveal an error do you need to go to the dealer.

3. What happens if I crash on my rear derailleur? Is there a saver mode?
The Di2 rear derailleur is equipped with a saver or recovery mode to get you home presuming the mechanism is rideable-or at least as rideable as a damaged mechanical derailleur. Just push the button on the system display for three seconds to reset into the recovery mode.

4. What's the weight difference between electronic and mechanical XTR?
It depends on your exact setup. Exact weights for the most common components are:
  • Front derailleur (FD-M9070 D-type) : 115 grams
  • Rear derailleur (RD-M9050-GS) : 289 grams
  • System display (SC-M9050) : 30 grams
  • Shifter switch (SW-M9050) : 64 grams
  • Front derailleur M9050 Di2 is 5 grams lighter
  • Rear derailleur M9050 Di2 is 68 grams heavier
  • Shift levers M9050 Di2 is 36 grams lighter (if you just use 1 it is 136 grams lighter)
  • Battery is 51 grams (extra item)
  • System Display is 30 grams (extra item)
For the 2x setup with only a right hand shifter (Synchro mode) M9050 Di2 has the same total weight as M9000 mechanical (there is a 47 gram difference on components, but the wires are lighter then cables).

5. Is damaging the rear derailleur more likely with electronic?
‏Your chances of breaking an electronic rear derailleur are similar to mechanical. In case of a crash there is a saver mode that helps to protect the derailleur a bit.

6. Is the FOX iCD system fully integrated?
‏Yes, it's even adjustable and compatible with the E-tube software.

7. Will Di2 XTR be super expensive?
‏It will be more expensive than XTR M9000 mechanical however it also adds a lot of features and advantages, and is easy to modify to your personal preferences. The price difference will be similar to the difference between mechanical Dura Ace and Di2 Dura Ace-about 40% more than mechanical for the full 2x setup.

8. When can we expect Di2 on XT?
‏So far we cannot say anything about that.

9. When is XTR Di2 available?
‏The fourth quarter of 2014.

10. What about wireless?
‏We present XTR Di2. What the future will bring regarding new products (even competitor) time will tell.