Exploding Tires!

[ijgrant]

I've been running a 32c Conti Twister in the front, with an Alex da22, and a 38c Scwalbe Snow Stud on alex dv30's in the back.

My brother and I were switching them around, so the snow stud was in the front, and the twister in the back. We had pumped the snow stud up to 70psi, and we let some air out, when the tube explodes, and we go deaf for a few minutes. The explosion blew the tire right off the rim, and shredded about 4 inches of the tube.

We came up with a few explanations

1. The tire/tube is simply too big for the rim
2. The tube was faulty
3. the tube was pinched

I'm really kinda freaked out, does anyone know if riding a narrow rim with a bigger tire is safe? has anyone else had an issue like this?

[squegeeboo]

the tube may not have been seated right. after installing but before pumping up to pressure, did you press along the edge of the tire to make sure the tube wasn't visible? I tend to blow out 1-2 tubes a year that way, due to being to lazy to check to make sure they were seated all right before pumping up to my normal PSI

[ken cummings]

Sure sounds like the tire was too big for the rim. I've had that happen a few times, always worked out that I did not have the tire seated properly. Tube inflates OK, lifts the tire past the edge of the rim. and pow. Only heard of a tire being over-pressured once. Mom had inflated her daughters' bike at a gas station. 200 PSI will do that to a little fat tire. Sprayed green sealant goo all over. :p