Shimano Ultegra Di2 FD-6770 Front Derailleur
Without the cost concern of Dura-Ace, the Shimano Ultegra Di2 group is simply brilliant. And with performance indistinguishable from their top-shelf version, this Ultegra Di2 FD-6770 Front Derailleur is part of what will become the new revolution in shifting. Will it overshadow Dura-Ace? We think not. The aesthetic differences are prominent, and the Ultegra derailleurs lack a touch of Dura-Ace's tidy, sleek design. The reason for the slightly bulked-up appearance of Ultegra is due to the use of off-the-shelf servo motors rather than the custom units as found in the Dura-Ace changers. The performance is identical, but the size of the internals determines the overall package dimension.Besides the affordability, we love that the Ultegra Di2 front derailleur has a self-trimming function. This is a marvelous feature and is so amazing you have to see it to truly appreciate it. There's an integrated central processing unit (CPU) that knows which gear your bike is in and thus knows where the front derailleur needs to be in relation to the chain. That's the coolest feature and probably the main reason they call their electronic shifting Di2 --Digital Integrated Intelligence. A second feature of the shifting that is much harder to see, but equally significant is the "programmed motion" of the derailleur. As with the rear derailleur, the front derailleur cage moves back and forth via a motor-driven worm drive. Once the low and high limits are set, the derailleur will take care of the rest -- you don't have to do anything else. As you make a shift, it derails the chain onto the big or small ring. Half a second after the shift, the derailleur will re-center on the chain. This re-centering reduces the chance of the chain bouncing off of either ring when you coast over bumps in the road. And it also ensures no chain rub on the cage plates. To be rid forever of that annoying sound is more joyous to us than you can imagine.