The digitally controlled 10-speed Dura Ace Di2. A new dimension of shifting. Precise and very fast shifting under all conditions and situations.
A new era in shifting precision begins. The Di2-technology (Digital Integrated Intelligence) reduces human errors in shifting. It features "Fly by Wire" for easiest shifting performance. It defines new standards for the high-performance sports.
There is no need for rethinking. The shifting operation is similar to the mechanical Shimano shifting system - just press the button without any effort. The program controlled front- and rear derailleurs shift the gears very fast and precise. The danger of chain drop is minimized. The rear derailleur is electronically adjustable, even when riding. The front derailleur adjusts automatically to the chain line in relation to the rear derailleur gear position. No concentration is wasted for trimming when riding, so the rider can spend full attention to the race.
New technologies in manufactoring and a generous use of titanium and carbon reduce the components weight without losing performance, stiffness or durability. A hollow forged chainring saves weigth and increases durability by 20% for better power transfer.

Included parts: Dura Ace Di2 ST-7970 2x10speed STIs, Dura Ace Di2 RD-7970 rear derailleur 2x10speed, Dura Ace Di2 FD-7970 front derailleur 2x10speed, Dura Ace BR-7900 brakes, Dura Ace FC-7900 crankset 2x10speed Hollowtech II, Dura Ace SM-FC7900 bottom bracket bearing cups, Dura Ace CS-7900 10speed sprockets and Dura Ace CN-7900 chain, battery pack SM-BTR1, charger SM-BCR1, power cord SM-BCC1-1, wire kit SM-EW79 and wire kit EW-797x.