Jerry, that's exactly the sort of damage I've often seen which is usually caused by "kerbing", especially if the tyres are soft. Not saying you did this, but it happens when the tyre is flattened against a sharp angle and the sidewall is crushed between the rim and tread edge at that point, severing the cords in the tyre carcase.
It can also happen if an obstruction in the road is hit which is enough to cause the same sidewall pinch pressure.
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It can also happen if an obstruction in the road is hit which is enough to cause the same sidewall pinch pressure.
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