Ultegra Front Derailleur

[Tpower59]

Hi everyone,
I’m at my wits’ end with a frustrating front derailleur issue and could really use your expertise. My FD isn’t shifting far enough outward on the largest chainring (52t), causing the chain to rub against the outer cage plate—even when I’ve maxed out the fine-tuning adjustment to +19.
Quick Setup Details:
•  Groupset: Shimano Ultegra Di 8150
•  Chainrings: 52/36t
What I’ve Tried So Far:
•  Loosened and retightened the FD mounting bolt on the hanger.
•  Reset the FD height and limit screws from scratch. (Note: Adjusting the limit screw pushes the bottom of the cage outward, but the upper part—where the rubbing is happening—doesn’t move enough.)
I’ve attached a photo and video below to show the issue clearly.
Any advice or troubleshooting tips would be a lifesaver—thanks in advance for your help!

PS : It is written H screw but I know the only adjustment screw is not a H screw

[frenzen]

I am not too familiar with the Di2 groupset, the first thing I'd suggest is manually moving the front derailleur by hand to check if it can reach the largest chainring without rubbing like you did in the video?. If it can't, then no amount of adjustment will fix the issue, it simply won't work.

I have a feeling the problem might be related to either the frame or the crankset compatibility with your frame.

[Tpower59]

Must be the frame : unscrewed the front derailleur plate and the carbon seems sunken

[Avalius]

Are you using an ultegra crank and chainrings?

[70Herald]

Must be the frame : unscrewed the front derailleur plate and the carbon seems sunken

That looks more like they flattened the tube for better stability. if you look at the FD holder, it probably will be flat to match the flat location on the tube...

Has this set up ever worked? or are you just trying to get it set up now?
what Crank set are you using?
Here is how I would go about trouble shooting find out how far the derailleur will move. (back off the limit screws) does it actually move far enough and properly (make sure there isn't a mechanical problem with the motion(

what about the crankset? is is centered on the bike (check distance of crank arms to center of bike)
Are there spacers shifting the location of the crank?
centerline of the front gears should match the centerline of rear gears.
If the crankset is shifted to far out on the gear side the FD won't reach properly... if so are there spacers on the gear side - move them to the opposite side (if actually needed)
Is the bottom bracket the correct size? - even if it is the correct size there are variations just to make us all crazy...

The FD is pretty simple... if the gears are in the correct location and FD aligned it should at least give some sort of decent results.

[hubba]

This is probably solved already but still just mentioning. The screw that moves just the bottom part of the derailleur is not a limit screw it's just a supporting screw. All limits are electronic. You need to set the limits in the e-tube app or manually in adjustment mode check for example better shifting website for instructions.