Just when you thought shifting quality and reliability couldn't get any better, Shimano ups the ante with the Dura-Ace Di2 9070 dual control levers. Some call the Dura-Ace Di2 9070 a "luxury group", but we have yet to meet any cyclist from professional to weekend enthusiast who didn't want ultra-reliable, precise, lightning-fast shifts across an 11-speed cassette with just a button click.
The biggest change from the 7970 Di2 is completely programmable shifting. With the 7970 you had one push, one shift. The 9070 Di2 gives you the ability to program virtually every aspect of shifting via a PC interface (available separately). The 9070 levers can be programed to shift one, three, five or the whole cassette just by holding the button. Shifting speed can be adjusted as well and the length of button hold before a multi-cog jump takes place. Button feel has also been improved with a more audible and definite click.
Ergonomics has always been pretty terrific with Shimano's dual control levers but reach new heights with 9070. Shimano has make it easier to reach the buttons from the top of the hoods where most people tend to place their hands. Reach is adjustable and the hood material has been improve with dual density rubber.
The levers use E-tube wires to make setup simpler than ever. Each lever has three E-tube ports so you can add two additional satellite shifters to each lever. So if you want to run both climber and sprinter satellite control - no problem. There are actually four different satellite shifters to choose from - sprint shifters, climbing shifter, TT/tri extension shifters and minimalist TT/tri extension shifters. Shifting options are virtually unlimited for the ultimate in performance, convenience, and safety.
All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions. Use Di2 system checker to update component firmware from http://e-tubeproject.shimano.com/