Bikes and Tech
This prototype rear derailleur isn't exactly...

Gallery: Shimano’s XTR Di2 prototyping process

Shimano's new XTR Di2 group wasn't always so polished.
Shimano XTR Di2
Shimano’s XTR Di2 group wasn’t always so polished. At an early sneak-peek event Shimano had this early prototype drivetrain on display. Photo: Lennard Zinn | VeloNews.com
Shimano XTR Di2
Shimano was playing with both the front derailleur and the latest XTR chainrings at this stage. The size of derailleur motor has been decreased considerably since this iteration. Photo: Lennard Zinn | VeloNews.com
Shimano XTR Di2
XTR Di2 in an early prototype phase. Photo: Lennard Zinn | VeloNews.com
Shimano XTR Di2
Shimano spent quite a bit of time perfecting the new shifters. The goal was to have each thumb paddle easily accessible, floating right in front of the thumbs’ natural position. Shimano played with lever shapes, actuation angles, and surface texture. The levers themselves are adjustable on the final version. Photo: Lennard Zinn | VeloNews.com
Shimano XTR Di2
This prototype rear derailleur isn’t exactly sleek, but all the key parts can be spotted — the plug, the limit screws, the roller clutch (borrowed straight off a mechanical derailleur), etc. Photo: Lennard Zinn | VeloNews.com
Shimano XTR Di2
Like Dura-Ace Di2, XTR Di2’s tiny motors are custom built. Photo: Lennard Zinn | VeloNews.com
Shimano XTR Di2
The front derailleur shown here is nearly complete. The system will use the same main derailleur body regardless of the number of chainrings used. The mounts can be easily swapped out depending on frame requirements. Photo: Lennard Zinn | VeloNews.com
Shimano XTR Di2
Compatibility problems exist between Shimano’s road and mountain electronic groups. Photo: Lennard Zinn | VeloNews.com
Shimano XTR Di2
The shift paddles rotate around the bar when pushed. Photo: Lennard Zinn | VeloNews.com
Shimano XTR Di2
That’s not a mini pump, that’s the XTR Di2 battery. The final version is a bit more refined, of course. Photo: Lennard Zinn | VeloNews.com