Originally Posted by
KoYak
On a really hot summer day, a tire blew out on me as I walked out of the garage. Only thing I can think of was that the extremely hot driveway asphalt caused the air pressure in the tube to increase the tire's limits. No damage to tire., Not realizing what had happened, went back into the garage, changed tubes, pumped up to tire pressure , and when out to driveway, only to blow out another tube! again, no damage to the tire.
If you do the math, your hypothesis doesn't work out.
A properly seated tire is not going to blow up from a rise in pressure, just from a hot day.
Assume you pumped the tire to its maximum rated pressure, there is still a wide safety margin built in to that maximum pressure figure, and the tire is going to be potentially subject to much more heat under heavy braking downhill, than the heat of just rolling out of your garage.
And given that a 10 degree farenheit change in temperature changes tire pressure by 1 psi,
http://www.tirerack.com/tires/tirete....jsp?techid=73 even if the air temperature in your tire went up 30 degrees it would not cause a properly seated tire to blow.
Odds are you didn't get the tube seated under the rim either time, and that caused your blow outs.