Shimano Ultegra 6800 front derailleur tension problem I'm building up a 2015 Salsa Colossal Ti with a full Ultegra 6800 groupset (though with the RS685 hydraulic shifters).  I'm having an issue setting up the front derailleur.  I've followed all the various tutorials online, but whatever I do, I can't seem to get the cable tension right.  Too little tension and I can't get the derailleur to hit the high limit screw.  But when I add the necessary tension, then the derailleur won't hit the low limit screw.  I either have chain rub in the 50/11 or in the 34/32.

I even have the little plastic tool that tells you whether the converter should be on or off (off in my case).  Out of desperation, I've tried the other converter setting, but no luck.

The factory built bike from Salsa comes with the same Ultegra components (apart from the RS685 shifters), so I know I should be able to get this to work.  Am I making some rookie mistake?
The rotational position and height not being exactly right would cause this. Shimano now has a more specific procedure then in the past to establish them, which you can see starting on page 5 of the dealer manual.

If following the procedure in their manual to a T doesn't work, the other thing you may be looking at is a situation such as Lennard Zinn describes in his column on 11-speed Shimano road FD setup where the cable anchor has to be set in an unorthodox position going over the top of the bolt. The dealer manual demonstrates this as a thing you're not supposed to do on the page 14, the two graphics on the right hand side of the chart. It may be worth a try.

As is pointed out further down in that column, problems with these derailers almost always revolve around not having enough cable tension. All aspects of the setup have little if any margin for error and they need as much cable tension as possible. They also need the low limit screw set super close. That  0-0.5mm inner cage clearance number on page 15 of the manual is one that's been around for a while and used to be more or less unrealistic, but they mean business now. It has to be all but touching, and it will work better if it's almost kinda sorta touching (the "0" end of the range). Usually it's the case that if you set it up in the stand for the chain to just barely touch the cage sometimes in the low gear, it won't rub when you're actually climbing because the chain is under so much more tension.