Electronic gear-shifting system

During shifting, this segment is pushed sideways by a relay operated mechanism like a railroad switch and picks up the chain that is currently running on the next cog.

[2] In 1992 the French manufacturer Mavic introduced their first electronically controlled gear shift mechanism called Zap at the 1992 Tour de France.

[4][5]In 1999 Mavic introduced the Mektronic, its second electronic shift system, which suffered from reliability issues and was subsequently discontinued.

[3] In 2001 Shimano introduced a set of trekking components called Di2 (Digital Integrated Intelligence), which included electronic shifting and automatic adaption of front and rear derailleur to riding speed.

[3] Three professional teams used the Di2 in the 2009 Tour of California: Columbia High Road, Garmin Slipstream, and Rabobank;[3] and several teams and riders, including George Hincapie, used it during the 2009 Tour de France[7] Also in 2009 Giant released a bicycle equipped with the Shimano Di2[3][8] and Trek began providing a battery mount and Di2-specific cable routing and stops on its Madone frames.

[1] On traditional bikes, the front derailleur is problematic because the chain can be under tension and has to make a large vertical jump between chainrings.

[20] Cyclists began to see a growing range of electronic alternatives to traditional mechanical shifting for derailleur gears.

[22] The system had been extensively developed and secretly tested over several years from initial design to a stage win in the 2015 Tour de France.

In May 2016 the company announced a hydraulic disc brake version of its wireless road group called SRAM RED eTap HRD.