"Pete Keillor" wrote in message
...
| On Fri, 19 Aug 2005 10:36:12 GMT, Nick Hull
| wrote:
|
| In article ,
| Pete Keillor wrote:
|
| My example was extreme for the point of illustration. Sure, the
| flexing in a radial tire is more complex. However, I've blown enough
| tires due to underinflation or overloading (boat trailer, radials) to
| have observed fairly intact tread with totally disintegrated sidewalls
| each time. These were 6-ply rated, with 50 psi pressure, and seem
| much more sensitive to load - inflation conditions than most passenger
| car tires.
|
| 6-ply rating means the sidewalls have 2-ply. Is ir any wonder that the
| 6-ply part lasts longer than the 2-ply part?
|
| Nope.

The tread bands are wrapped circumferentially and are the best wrapped
part of the tire due to the least amount of flex needed and highest
pressure. When a tire fails the tread is rarely part of it. When tires
explode (car or aircraft tires, even) they blow out sideways, which is why
you see a roll in cage at places that do semi truck tires.