Originally Posted by
davidad
The sidewall pressure is 1/2 the amount that will blow the tire off of the rim.
Couple of things,
1: got a link to a reliable source for this "factoid"
2: There are plenty of larger volume tires that would either explode or damage the rim long before they reached twice the sidewall pressure. Good example is the Surly Extra Terrestrial, it doesn't even like being pumped to it's max pressure of 60psi, at which point it would be way above the maximum rated pressure of any rim you'd fit it to, let alone pumped to 120psi..