Type: PartsThe DURA-ACE Di2 rear derailleur sees a ground-up re-design which takes advantage of Shimano’s Shadow RD architecture first introduced for mountain bikes. This low-profile design delivers a sleek appearance while improving its’ ability to withstand crash damage.
What is Shimano Di2? Shimano’s Di2 (Digital Integrated Intelligence) is a shifting option to Shimano’s proven mechanical shifting. Instead of mechanical cables, Di2 is an electronic gear-shifting system that enables riders to execute shifts with electronic switches vs. mechanical shift levers. Through the use of Di2, shifts are fast and precise and customization options are endless. The most important thing to remember is that you, the rider, is always in control of what your system does or can be pre-programmed to do.