Canadian Cyclist


May 31/14 7:30 am - Shimano Releases Di2 Electronic Shifting for MTB

Posted by Editoress on 05/31/14

It has been a poorly kept secret that Shimano was going to port its very successful road bike Di2 electronic shifting system over to mountain bike, and the official announcement finally came here at the Albstadt World Cup in Germany.

Called XTR M9050 Di2, it will integrate with the latest version of XTR - the flagship MTB group from Shimano - which was introduced last month [see Daily News: April 11th].

The 11-speed Di2 system consists of shifters (called Firebolt), a display unit, front and rear derailleurs, wiring and a battery with holder.  The system is available to work with one, two or three chainrings, and the Race or Trail versions of XTR.  One of the most interesting optional features is Synchronized Shift - a programmable system allows one shifter to control both front and rear derailleurs, so that when you shift up or down it picks the optimal combination of front and rear cogs.  It also allows control of compatible Fox suspension components (this is something that we have commented on before, with shots of riders such as Geoff Kabush testing prototypes).

The price difference depends upon the exact setup but it is similar to the difference between mechanical and electronic on the Dura Ace road series, and Shimano says will average about a 40% premium.

Shimano says that it will be available on the market at the end of this year (last quarter of 2014).

We have only had a chance to try it out in a display setting but, as you might expect given Shimano's success with road Di2, it appears to work perfectly.  Julien Absalon (BMC), Dan McConnell (Trek Factory Racing) and Fabian Giger (Giant) are all scheduled to race on it tomorrow (Sunday) in the World Cup.

Now, the details:

Shimano XTR M9050 Di2 electronic shifting integrates with XTR M9000 mechanical components in a variety of Race or Trail "Rider Tuned" 1x, 2x, or 3x drivetrain configurations. The new 11-speed XTR M9000 drivetrain introduces Rhythm Step gearing which provides range and ensures rhythm, no matter the rider or terrain. With the additional efficiency, new shifting options and personalization of the digital Di2 system, riders now can control their ride like never before.




M9050 rear derailleur


M9050 front derailleur


XTR M9050 Di2 has undergone over 20,000 kilometres of testing to ultimately refine how precision and logic can deliver a completely new mountain bike ride experience. Di2 digital shifting is seamless, instantaneous and can be custom tailored for any rider. 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.

Over half a decade of experience in electronic shifting components have culminated with the introduction of Shimano's most advanced Di2 system ever. XTR M9050 Di2 features the programmable, upgradeable and expandable attributes of Shimano's latest Di2 shifting systems, which now debuts intuitive shifting control. Shimano's E-tube wiring and electronics make expanding Di2 shifting systems easy and also enable riders to custom program and upgrade the system through a computer software interface. Riders can program and control the shift patterns for single or multi-shift modes, the speed of those shifts and the actions for each shifter and button. With XTR Di2, Shimano Synchronized Shift is also custom programmed through the Di2 program software, allowing front and rear shifts using a single shifter.




Shimano Synchronized Shift: two derailleurs, one shifter

The new Shimano Synchronized Shift function and programmable shift mapping allows riders to change their focus from the physical effort of shifting to the trail ahead. A programmable option with XTR Di2 M9050, Shimano Synchronized Shift creates an intuitive shifting experience on the bike through customizable synchronized front and rear shifting via a single Firebolt shifter.




• Improved efficiency - The XTR M9050 derailleurs communicate gear position and automatically execute front and rear shifts when riders select a sequentially larger or smaller gear. This improves efficiency by minimizing time spent on smaller chainrings and cogs.
• Personalized shift mapping - Riders can program when front shifts occur through two customizable shift maps based on terrain and personal preferences. An audible alarm will warn of an upcoming front derailleur shift so that a rider can choose to remain in a given gear.
• Total control - On a mountain bike with both front and rear Firebolt shifters installed, the rider can manually shift at any time. Synchronized Shift becomes another available tool for riders, not a requirement. With a touch of a button, riders quickly choose between synchronized maps or choose manual mode for complete control.

The new, easy-to-use XTR Di2 Firebolt shifters make shifting a simple rider reflex and deliver customizable ergonomics that improve bike control. Shimano's Firebolt customizable shift button placement is determined entirely by human ergonomics, not by the needs of a mechanical mechanism. Firebolt shift levers are now exactly where thumbs naturally rest, allowing riders to put more grip on the handlebar and control the ride with more confidence - especially in rough conditions.

• New ergonomic rotary shift lever design matches natural hand movement.  Independent lever position adjustment
• Short stroke, perfect click levers provide faster, more accurate shifting
• Increased trail readiness thanks to decreased shift effort and superior ergonomics
• Programmable, multi-shift and Shimano Synchronized shift functions, including control of Fox Racing Shox suspension components.





Shimano's first mountain bike specific Di2 rear derailleur is also its most technologically advanced. Introducing Shimano Shadow RD + stabilization to Di2, the RD-M9050 couples unrivaled chain control that aggressive riders have come to love with shift performance that doesn't degrade over time. Whether cross country or trail riders run a 1x, 2x or 3x drivetrain, the ultra narrow profile help protect the drivetrain in tight trail sections. The refined rear derailleur geometry further improves the performance stability while Shimano Synchronized Shift enables system communication with the front derailleur.

• Instantaneous shift response to rider input
• Seamless gear changes
• Shimano Synchronized Shift compatible
• System communication with front derailleur
• Advantage in all conditions
• E-tube electric wire transmission guarantees stable performance
• Low profile positions RD safely away from trail obstacles
• 1x, 2x and 3x compatible with GS and SGS cage options

Long regarded as the most notable feature of Shimano Di2 shifting, the front derailleur performance remains the best in the industry, now with the additional capabilities of Shimano Synchronized Shift. With XTR M9050 Di2, front shifts require the same light effort of a rear Di2 shift, reducing effort and freeing up the rider to focus on the trail. The FD-M9050 uses computer controlled auto trim as the chain moves up and down the cassette to keep the drivetrain running smoothly. Shimano Synchronized Shift compatibility allows a single shifter to control both front and rear shifting.

• More powerful shifting than mechanical (+25% compared to M9000)
• Reliable gear changes under load
• Computer controlled auto trim
• Optimized Di2 cage profile and gear tracking
• Shimano Synchronized Shift compatible
• System communication with rear derailleur
• Advantage in all conditions
• Modular mounting structure


Digital Di2 E-tube electronics allow the inclusion of the handlebar mounted SC-M9050 Display Unit for monitoring important Di2 data: gear selection, battery level and shift mode. The SC-M9050 not only provides data, but also is the convenient interface where riders will plug in and charge the system from the handlebar - an especially handy virtue when running an internal battery.  With the battery charger for the internal battery, the system can be connected to a computer and all settings for the shifter can be changed; synchro mode or multi-shift setting. Error check or diagnostics will require a dealer visit.  The expandable E-tube platform also means that integration with electric-controlled suspension from FOX is a reality.

• Multiple simultaneous display fields
• Battery level
• Gear position
• Shift mode (Synchronized or Manual)
• FOX iCD position (Climb or Descend)
• Shimano Synchronized Shift mode switch
• Change between S1, S2 and Manual shift maps
• Audible Shimano Synchronized Shift notification tone
• Precision derailleur adjustment
• Easy access adjustment mode
• Numerical adjustment indicator
• Junction A function
• Battery charging port
• Three E-tube wiring ports

Shimano's XTR M9050 shifting system uses the same E-tube platform introduced with road Di2 groups that is programmable, customizable and allows for expansion and further system integration. Wires are offered in a wide variety of lengths for bikes of all sizes and shapes and cable routing options will connect the various junction points. Unlike traditional cables and housing, wires are not affected by trail and weather conditions, providing consistent performance in this waterproof system.


• The SM-BTC1 mounts Shimano's cylindrical SM-BTR2 Di2 battery on a bike's water bottle bosses and also acts as a Junction B, connecting wires from the shifters to the battery and derailleur.
• Junction B function
• Six E-tube wiring ports with cable organizer
• Case is only available for riders with an existing battery
• Clean appearance thanks to internal wire routing
• System expansion possible thanks to the E-tube platform


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
• Shift switch (SW-M9050): 64 grams

Compared to mechanical:

Front Derailleur = M9050 is 5 grams lighter
Rear Derailleur = M9050 is 68 grams heavier
Shift Lever(s) = M9050 is 36 grams lighter (if you just use 1 it is 136 grams lighter)
Battery = 51 grams (extra item)
System Display = 30 grams (extra item)

For the 2x setup with only a right hand shifter (synchro mode) M9050 has the same total weight as M9000 (there is a 47 gram difference on components, but the wires are lighter then cables).


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