Originally Posted by
Polaris OBark
Exactly.
I was one of the people (via previous user-name before going into the witness protection program) who was saying you could get away with keeping the Ultegra front derailleur -- based on my previous experience. It worked great until it didn't. I think I have a tendency to mount my derailleurs too high, not just with this bike, and I've moved it down about 2 mm now. I suspect I didn't bother at the time, since it worked, and I reasoned it would be easy enough with the band clamp on my steel frame (it was).
What I am not clear about is why it just started happening very recently.
Okay, thanks for the confirmation. When I got a GRX 11sp crankset (48-31), the shop tried using it with my Ultegra FD -- no dice. Had to add the GRX FD. My understanding is that some bikes will allow the GRX cranks without changing the FD, some will need the dedicated FD. I'm guessing that yours is an edge case, and a little fettling will get it working again.