Ultegra 6800 front derailleur trim

[robsc]

Just asking if anybody else has had the same issue? My bike shifts prefectly between small and big chainring but when I want to trim the derailleur inwards when going to a larger cog on the sprocket it hardly moves, maybe a quarter of a mm . I had a look at another chaps bike this morning after a ride and his trims a good mm inwards . I have tried tensioning and de tensioning the barrel adjuster but it doesnt do anything. Could a worn shifter or even a bad cable housing cause this? 

Edited October 13, 2022 by robsc

[Martin PJ]

If I have derailleur setting problems, first thing is change cables and housings. This eliminates most things. Front derailleur housings should be changed every couple of years, back once a year or more. They rust, even when standing still, this causes problems. 

If this doesn't work, try find a video on Youtube where someone sets up the derailleur, similar model. Sometimes it doesn't work exactly the way you think it obviously should work.

[David Marshall]

These 11 speed FDs are a bit tricky to adjust.  The newer 8000 series is more accommodating. Few, if any, bikes come into my workshop with both the high and low trims functioning properly. 

The Shimano dealers manual covers the set up (all 18 pages) so I will assume that yours is correctly mounted and just give you the hack here.

The secret is in the cable tension which has to be tight - and I mean tight!  This is hard to get right with the stupid 4mm cable pinch bolt and a short cable end so with the shifter in the lowest position place a 5mm hex key into the derailleur as in the picture.  This allows you to attach the cable without excessive tension or stripping the bolt head and crunching the cable.  Check that the derailleur moves in both the upper and lower trim positions and you are away.

[shaper]

I use a cable stretcher pliers. Icetools and Pedro's make them too. 

If for any reason that does not work then I use a Shimano MTB brake block spacer