Originally Posted by
gugie
If you're settling for an engineer, I are one.
FIFY.
Consider the time duration of each of the rubbing events. The crank arm thickness is maybe equivalent to two chain links. The ring was, what, a 52T? The constant rubbing would be in effect for 26 times longer. Both would be at approximately the same radius to the spindle. So unless the derailleur-strike event applied 26 times more ******ing force, the rubbing would definitely produce more drag.
I know someone who prefers not to shift his Campy FD at all lest he wear away the inside of the plates. (Seems kinda' silly to me.) But if I wuz you though, which I'm not for obvious reasons, I'd be more concerned about the stress on the FD from the potentially much-higher-stress impact of the crank arm.
And I'd check its alignment on the ST.
You can correkt my speling if you wish.