It happens. Seriously, they are sidewalls, and there is a god chance of them chipping.
If you file down where the topsheet meets the sidewall it helps. Just a little to make it rounder. try it on your next pair of K2 or whatever.
My bents were gettings a little ravaged in spots, and I filed down the corner a little, it makes a lot of difference, not much new chipping since then.