I had planned on going for a ride this morning before work, so last night I prepped the bike. I pumped up the tires (700 x 32 Ritchey Speedmaxes) to about 90 psi, which is what I usually do when I'm going to be riding on pavement. I got dressed in the morning and grabbed my bike to walk out the door and it appeared that the tube had completely exploded. there was about a 6-7 inch gash in the tube and part of the tire bead had been unseated. I can't see anything on the rim or tire that would have cut the tube, and the bike was just sitting in my den where nobody/nothing would have even touched it.

Is this a case of rubber fatigue? It kind of boggled my mind that the thing just exploded on its own.

I had a very similar incident. But it was a 26" X 1-3/8th inch tube made under the name Inline. It was a brand-new wheel I'd just trued, with a brand-new Panaracer tire on it. I had also put on a Velox tire-strap in 22mm. There was nothing sharp in the brand-new tire or rim, and the tube blew up. I'd pumped it up to 55psi. Set it aside. And BANG!! It sounded like a 9mm handgun (I'm a gun nut).

I removed the tire and tube. It blew-up in the direction of the outside of the tire, and a couple of inches away from the valve - the valve had escaped the blast. And it was a 4" to 5" inch-long gash of jagged rubber. Never had that happen before.

The tube was trapped under the bead of the tire when inflated, or the tire was not properly seated.

Nope - good guess though. I always partially inflate my tubes and work them all the way up and in the tires. Unless it's a ultra-tight fit. My best guess was it was cheap, cheap, cheap rubber. I promptly bought a pair of new tubes - made by a different (I hope) company.

This is a common problem and happens when a small portion of the tube gets caught between the tire bead and the rim. If the tube is caught between the edge of the bead and the bottom of the rim it may not be visible, but it will find its way out and.... KERRPOW! It's happened to me five miles down the road.

Al

Whatever done the deed - I'm glad it happened in my shop before I installed the critter. I was expecting the cops after someone reports a gunshot.

It doesn't sound like you did anything to cause it. I've seen tubes just explode on the seams before. Was it on the seam that it broke?