Dura Ace di2 front derailleur 10 speed (7970) not shifting correctly. Moving back and forth with clicking sound. How do we fix?
Moves partly to the right, clicks a couple of times then moves back.
Cycling - Shimano - Dura-Ace Di2 7970 Front Derailleur Clamp Adapter 32
Answers & Comments
First, is cable tight, it may be that the cable has loosened or stretched. In this case, Put chain on inside spocket, loosen hex head bolt, pull tight, retighten hex head.
It also could be the limit screws have vibrated loose. There are two of them on the top of the derailleur. Make small adjustments in one screw, check to see if it improves shifting or makes it worse. You didn't say whether it was the small or larger spocket. The limit screws control how far in or out the derailleur moves. Read more on Shelton brown .com under derailleur heading