My chain rubs against the front derailleur when I am on my large chainring and smallest cog. But it is not a consistent rub, it only rubs once with each pedal revolution. As if the chainring were bent.
If I set the derailleur with more room, then the chain derails to the outside of the chainring.
The chainring doesn't seem bent (though a few teeth have seen better days) and the problem is definitely worse when pedaling hard or sprinting.
Any advice appreciated!