-
My feet naturally turn out like clown shoes, so all my cranks and seat stays are rubbed bare because my heel kicks in. And the older ones actually have wear on the metal of the frame. You don't notice it when it happens; you don't feel your heel strike something.
I had a bike fit years ago where they put motion trackers on you and all that and the guy didn't mention it as a problem. But when I was a kid my dad was constantly telling me to point my feet forwards.
It looks like some folk do. Quite often see an ad on eBay saying ‘a bit of heel rub on the cranks’ and they’re bare metal.