Di2 front derailleur adjustment

[pclay]

Hi

I have a Cannonade synapse 2016 with Ultegra Di2 gearing. Over the last year I have had problems with shifting on the front derailleur. The front derailleur is over shifting and causing the chain to come of on the outside of the chain ring.

It started when going downhill and in 50/11 combination. The chain would jump off the big chaining towards the crank.

The chain now jumps off more regularly when shfting up into the big chainring.

I have tried to adjust the front derailleur by using the high and low screws, as well as the electronic setup using the junction box button. I cannot get the distance between the cage and the chain to the recommended 0.5-1mm. looking at the photo, that's the closest I can get. I think this is causing the chain to come off.

Any help on how I can adjust the front derailleur? Is the cage of the derailleur bent?

Thanks

 

[Yellow Saddle]

Lets see a photo from the side, with the chain on the small chainring. Make the photo square-on from the crank's centre i.e. crouch down and take the photo in line with the crank spindle.

 

[pclay]

Heres some more photos. Actually, I've noticed there is a fair bit of play on the derailleur cage. This might be the problem?

 

[pclay]

Front derailleur play:

View: https://www.youtube.com/watch?v=jxR9uqIBkLo

 

[Ian H]

I'm guessing a worn chain.

 

[faster]

The cage should be parallel to the chain - it looks miles out in that video.

The deraillure needs to be rotated round a little on the seat tube if it's band on. If it's braze on, something is probably bent.

 

[Yellow Saddle]

Heres some more photos. Actually, I've noticed there is a fair bit of play on the derailleur cage. This might be the problem?

View attachment 512099

The FD is too high above the chainring. There should be a gap of only 1-2mm between them. Lower it.
Secondly, the tail swing play can be dialled out with a screw that pushes against the seat tube. There's an adjuster in there, have a look.
Thirdly, a worn chain never causes shifting problems unless we're taking waaaaay too worn to even operate properly.
Yes, it does look like it is not parallel with the chain, but Di2 11-speed FDs are meant to be a bit tail-out.
Let's get that all OK before going further and speculating.