Yes, because of the spacing difference.That doesn't show the 9000 or 6800 FDR is compatible with the 9100 front chainset, is that because of different spacing (a little wider) between the rings on the 9100? Interesting the 9100 FDR works with the 9000 and 6800 though.
Do you know if Shimano has changed the FD multi-shift limitations?I have a front 9100 derailler on my otherwise all 9000 bike.The FD works better than the original 9000. I put the 9000 FD on a friends bike with an otherwise all 9100 drivetrain(52/36) - no problems. The 9000 worked better on his bike than I could ever get it to work on mine.
I converted my Cervélo S5 with the bar end junction box, and that’s all I needed....plus a new Enve SES bar that takes internal routing.I am currently using 9070 Di2 with the D-Fly unit. If I want to change to the bar end junction box EW-RS910 with inline wireless unit EW-WU111 and the new battery BT-DN110 with the brain for synchro shifting, retaining the existing 9070 shifters, frond derailleur and rear deraileur, is there anything else that I need to take care of for the upgrades? Thanks.