Originally Posted by
relyt
It is normal to have rub in extreme gear combos, that is why you aren't supposed to use them.
+1. Small chainring, middle to large cogs on rear; big chainring, middle to small cogs on rear. If you find yourself riding on the inner chainring mostly, you can shift the FD to not rub on the inner rings. You can also add a smaller washer to the FD at the screw that holds the 2 arms together, to widen it a bit.