Shimano XTR Di2 - Electronic shifting comes to mountain bikes
Motor controlled shifting with clever sequential mode and interesting integration
This article originally appeared on Bikeradar
Shimano have announced details of a new Di2 electronic version of its top-tier XTR mountain bike groupset.
Rumours, as well as leaked images of the group, have been floating around the net for some time, but now everything is official we can give you the full run-down.
XTR Di2 in a nutshell
XTR M9050 marks the first migration of electronic shifting technology into the world of mountain bikes. The system will use one battery and remain wired, using already proven parts from Shimano’s Ultegra and Dura-Ace road Di2 groups.
So what are the advantages? Shimano claims that XTR Di2 will offer faster and more accurate shifting. Also, with no cables to stretch, it’s said to offer shifting consistency that a mechanical transmission cannot match. Whether that's true remains to be seen, but one part of XTR Di2 that we really should be taking notice of is Syncro Shift – for those who are running double or triple set-ups it could be a game changer.
Syncro Shift allows the rider to control both front and rear derailleurs with one shifter. Simply shift up or down and the transmission will follow a pre-programmed (and customisable) shifting map, moving both derailleurs when necessary to find the next ratio while maintaining a good chain line. So, that’s less clutter at the bar and more time to worry about things other than gear selection.
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XTR Di2 shares its crank, cassette and chain with Shimano’s recently announced mechanical XTR M9000 groupset, so that means Di2 options for single, double and triple transmissions.
Individual components
RD-M9050 rear derailleur
Bottle cage mount will not be the only option (L) – notice the wires emerging from the head tube (R)
The battery unit as well as the wiring for XTR Di2 are identical components to the ones used in Shimano's electronic road groups. The battery can be mounted on a bottle cage, in a seat tube and can even be contained within the steerer unit of certain forks (although full details on this haven't yet fully emerged).
Pricing
Di2 technology has, just like it did for the first generation in the world of road, debuted at the top-end of Shimano's mountain biking range. The pricing alone is likely to keep these parts out of the hands of anyone other than Shimano-sponsored athletes and the very wealthy.
Rear derailleur — £429.99 RDM9050GS (short cage) and RD9050SGS (long cage)
Front derailleur — £269.99 FDM9050
Right shifter — £149.99 SWM9050R
Left shifter – £149.99 SWM9050L