Sticky front derailleur
[Zillionth time trying to post this, apologies if I multipost... when if BF going to be stable again??]
Two things are happening, and I imagine they are related (double chainrings, BTW, not triple):
1) the FD won't move when trying to shift from the big ring down two the little ring
2) in the little ring the FD doesn't move as far as the limit screw will allow so there's rubbing in the biggest and sometimes even second biggest cog
The above can be fixed with a manual adjustment (e.g. hand while on the workstand and kick while riding), hence my opinion that the limit screws are set correctly. Note that I've loosened the cable tension with the barrel adjuster too, with no discernable effect. Finally, this is something that seems to have come on by use, i.e. I haven't made any adjustments recently which could be the cause.
I sprayed some Tri-Flow in there to lube the mechanism and ****ed back and forth several times (while on the workstand, duh) but that doesn't seem to have helped. Any ideas?
I would take the cable loose and work the fd by hand and see if it moves freely. It may be a cable problem. You might also pull on the cable and shift at the same time and see how the cable moves.