Originally Posted by
dddd
That sort of damage, if it is where the plies wrap around the bead, is often caused by the pinching action of tire levers on the casing fabric.
The bead under tension is much like a hard edge having a small radius, thus able to concentrate force at a tangent contact area of the bead, thus potentially severing the fibers of the casing, with resulting separation of the casing from the bead under inflation pressure tension.
Even when using a sliding motion with a tire iron along the rim and tire bead, I've seen the cloth chafer strip shear right off, and have seen the rubber peel away on tires that have no cloth chafer strip along the bead edge. An aged tire will be particularly vulnerable to such damage.
yes, that is all true. I've definitely seen tires so dried out that the rubber would crumble if you used a tire iron. They're pretty old by that time.
The tires that failed on me, though, were new. In fact I don't think I had ever used a tire iron on either one.