Shimano Di2

Drivetrain
Shimano announces wireless XT and Deore Di2 electronic drivetrains
Drivetrain
Is Electronic Shifting Really That Amazing?
  28
Mountain Bikes and Gear
Mountain Bike Controls Go Wireless, From Drivetrains to Dropper Posts and Suspension [Podcast #192]
  2
Mountain Bikes and Gear
Shimano Di2: The Electronic MTB Drivetrain for the 1.4%
  6
Culture
News: Pivot Releases New, Lighter Mach 429SL Carbon