Front derailleur?
 

Am struggling to keep my Ultegra front derailleur aligned and adjusted. Always liked the old XTR front on my off-road and wondered if it can be used on a 53 tooth cog on a roadie. The lit says no, but has anyone done it anyway?

Yes, XTR front derailleurs were spec'd as OEM on road tandems throughout the 90's, perhaps even in the early '00's before Shimano began to offer Ultegra & DuraAce in triple grouppos.

i've got Ultegra fronts and they work well. never require any adjustment.

Be sure to double-check derailleur mounting bolts. There is nothing quite like a non-fixed derailleur....

Stripped one in Victoria on a 500 mile cross country trip which include 200 miles of gravel. Ended up having to put in a Tiagra to get home. I have two or three triple front Ultegra der on tandems and one on a touring bike. They are constantly in need of adjusting. I just bought a nos xt front and rear der - thinking about putting these on.

Front Derailleur
 

Two problems:

1) The current XTR F/D is designed for a max big ring of 44-46 teeth, so the radius of the cage will not be optimum.

2) The more important issue is that a mountain F/D has a different actuation ratio than a road F/D. IOW, the cage will move a different amount per length of cable pull. This is not a big issue with friction shifting, but with index front shifting it is the kiss od death:)

Rich does this mean an older xt or xtr front der will work - what year did the switch take place?

The max ring size has varied over the years. I do know that the mid ninety's was OK for road size rings.

I don't know if the actuation ratio actually changed. It may be the same as it always was, just didn't matter until indexed front shifting came along.

The actuation ratio did change but I can't remember which year.