I don't know anything about manufacturing tires -- but that statement does make logical sense: Aramid and Kevlar are essentially impenetrable -- but fairly light weight. It seems like the puncture resistant tires are made by ADDING a belt around a regular tire which makes it stiffer and heavier. I have to wonder why they don't simply make the whole casing out of Kevlar and skip the added belt --that would eliminate a lot of the arguments against puncture protection.