Shimano's Ultegra Di2 RD-6870 Rear Derailleur features much of the same level of performance as the Dura-Ace group without the podium-topping price tag. Taking its cue from the Dura-Ace 9070, the profile of the 6870 has been trimmed, making it leaner than the previous Ultegra Di2 rear mech. The... Show More