Problem with FD twisting (I think)
 

Hi, so my road bike has a braze-on (actually riveted-on) tab for the front derailleur. I'm having an issue where my SRAM red FD works fine when initially set up, but goes out of whack after a few rides. I think it's usually twisting clockwise from above (i.e. the tail of the FD is migrating inwards). Note that I'm not talking about the yawing motion that this FD makes; I know all about that, don't worry! I suspect that the aluminum tab (it's a carbon frame) might be too soft, and is getting subtly bent, but it may just be the FD rotating within the tab. Is there any way to fight this? Some sort of friction paste? I'd even consider some kind of epoxy or glue if I knew it would help.

It sure as hell would be annoying to have to get a new frame just because of the FD tab. Why it's aluminum is beyond me; for a tiny piece like that, I'd have thought steel would be a better choice.

Before you do anything, use a reference of some kind, ie. view from the top when the FD is trimmed so the outer plate is directly over the outer chainring, to confirm that it's actually moving. Or try applying some twist by hand and see if it does.

If it is moving, I doubt the fitting is bending, especially because it's moving in the unlikely direction. So look for a cause, like excess shift pressure when upshifting. You can try a traction material such as CF assembly paste or medium grit lapping compound to keep the FD from slipping in the fitting, but shouldn't need it.

If it is moving, you have another issue causing it, such as the FD being too far forward with respect to the chainring, and need to find what it is.