Mountain Bikes ‘Go Digital’ With Shimano XTR Di2 Electronic Shifting

Mountain bikers just got a digital option. Today, Shimano introduced “the world’s first production electronic mountain bike shifting system,” called the XTR M9050 Di2.

Electronic shifting has been an option for road bikes for five years. The mtb version is the same Di2 platform, but built for the bumps and special conditions of the trail.

It runs off a single battery wired to auto-shifting derailleurs. An LCD is mounted on the handlebars.

Lithium-ion Di2 battery

It integrates with the company’s XTR mechanical components. Bikers “can control their ride like never before,” as Shimano puts it, including programming the Di2 software to allow front and rear shifts using a single shifter button.

You can press the trigger while riding hard and the system will shift automatically. Shimano states, “derailleurs communicate gear position and automatically execute front and rear shifts when riders select a sequentially larger or smaller gear.” This improves efficiency, the company states, by minimizing time spent on smaller chainrings and cogs.

Shimano touts it’s tested the digital setup for more than 20,000KM of trails.

You can also shift the old way — with FIREBOLT shifters installed, a rider can manually shift at any time and override the software.

Keep an eye out for XTR M9050 Di2 on bikes this fall, as the new system is expected to ship in Q4 of 2014. We have been eagerly awaiting this release for a long time as we are huge fans of the Di2 road system. We don’t have pricing yet, but are expecting it to have a price tag as high as our expectations. —Stephen Regenold

Synchronized shifter

Sean McCoy

Editorial Director Sean McCoy is a life-long outdoorsman who grew up hunting and fishing central Wisconsin forests and lakes. He joined GearJunkie after a 10-year stint as a newspaperman in the Caribbean, where he learned sailing and wooden-boat repair. Based in GearJunkie's Denver office, McCoy is an avid trail runner, camper, hunter, angler, mountain biker, skier, and beer tester.