Originally Posted by DannoXYZ

Yeah, the max-pressure rating on a tyre is common set at 1/2 of what it really takes to stretch and blow a tyre off the rim. Most likely it's a tube-mounting issue. Mark the valve-stem position on the tyre and inspect the hole in the tube. Most likely the tyre is perfectly fine with no holes in it. The tube most likely squeezed out somewhere either on the rim-strip side or through the gap between the tyre and tube.

This is by far the most common 99% of the problems out there. When mounting a tyre, DO NOT immediately pump it up. Inspect the gap between the tyre and rim first. Pull the tyre sideways so you can look down this gap, you should not see any tube showing. Move over a little and pull the tyre sideways again until you've inspect the entire side. Then pull it over to the opposite side and inspect the other side of the tyre. Only when you've confirmed both sides of the tyre isn't pinching the tube, only then would you pump it up.