Originally Posted by
ivan_yulaev
On modern cranks the teeth are uneven to help shifting. Wear on a crank should be pretty even and should make the teeth look like shark's fins. What you're describing sounds like the shifting aids that exist on modern cranks.
Possible, need a picture to really tell.
If they really are worn, I'd go for a 53/39 chainring combo. On the flats, that should be quite nice