Di2 dropping chain

[Binky]

I have a Canyon with 11 speed Di2, the 6800 version so it's pretty old.
Anyway, recently on rides once or twice it drops chain when I shift from small ring to big but it's dropping chain to inside of small chainring which seems counter intuitive.
Otherwise it's perfect gear changing, no issues. I've checked set up and clearances etc when home on stand and all looks spot on.

Any ideas? It seems the front deraullieur is on occasion randomly moving way too far inboard yet when changing from small to big. Never get issue gong big to small.
I'm at a loss as to why.

 

[fossyant]

Worn chain rings or worn chain ? Worth getting a chain catcher ?

 

[Binky]

Chainrings are new this year as a result of debonding issue known to some Shimano ones. New chain also.

Chain catcher worth considering but I'm just wondering what is going on to cause it.

 

[Punkawallah]

Is the BB worn? If the chain set is ‘wobbling’ the chain might miss the ring.

 

[fossyant]

Chainrings are new this year as a result of debonding issue known to some Shimano ones. New chain also.

Chain catcher worth considering but I'm just wondering what is going on to cause it.

I'd tweak the limit screws a little.

 

[Binky]

BB seems fine. Only ever happens out on a ride (of course) I've done a load of checking and changing whilst on bikestand and it's perfect.
It's almost like a glitch in Di2 where it decides to go inboard not outboard.

 

[Sharky]

When changing small to big at the front, which sprocket is the chain on at the rear?

 

[Trev the Rev]

Is the stabilising screw in the right position, how is tbe angle of the FD ?

 

[Trev the Rev]

My guess is it's slightly loose and thd stabilising screw isn't doing its job as it needs something to push off .When it's shifting up when it meets resistance it will be moving back slightly ,gaps will look OK when looking at it but when under stress tge shift isn't going high enough to get it on the big ring