I went for my first ride in about 3 weeks this morning. Great day, partly cloudy, mid-30's, no wind. Rode for just a little over an hour then came home and put my bike back down in the basement to keep it out of harms way from the pending x-mas explosion.

About 30m later I took the kids to the pool and the H went his studio, also in the basement, to play for a bit. He called me and said he'd just heard a loud "pow!" and was looking around to see what it was. He figured out it was the tube in my back tire.

These tubes, lbs dude said they were "top of the line" (don't recall the brand), only have about 80 miles on them and I filled them with sealant because I'd been having a string of flats.

What would cause a relatively new tube to explode like that?

Check for glass lodged into the tires, or maybe your rim tape is bad/aligned wrong.

Damaged valve?

ninjas?

pinched between bead and rim, little bit o' glass, half a staple... anything.

Meh, it happens. It's just not so fun when it happens right before a race...

30 deg outside- pumped to 140 psi- then into a warm basement and expanding gas on a "Poorly" fitted tyre and tube.

Thanks, I'll check for glass or other debis in the tire. I had the pressure right in the middle of the recommended range.

That means nothing if the tube was pinched. You're lucky it didn't blow when you were riding.

I would say most likely from going from cold to warm, then again... 140psi? Isnt that a bit much?

Without knowing what tires he's using on what rims, impossible to say. Although 140psi would pretty much necessitate 700x23's or lower and possibly tubulars.

OP didn't mention 140 psi.

we're not talking about the OP.

They weren't green, were they?

Most tube issues are caused and/or controlled by the following 3 factors:

1. Inflation pressure.

2. Mounting procedure.

3. Condition of components. (rim strips, no foreign objects in the tire, rim damage, etc.)

Your flat was caused by one of the 3 factors above. Figure out which one caused it and you might not repeat it.

Honestly it sounds like improper mounting to me from what I have read.

Did the tire blow, or the tube?

The tube isn't intended to have any strength as such. The tire has to contain it. Usually in a blowout, the tire fails in some way and that automatically makes the tube fail. If the tire blew off the rim, that's a tire and rim problem, not a tube problem. If the tire blew out while it was setting there, that's a tire problem, not a tube problem. When a tire blows out in one way or another, it won't matter what the tube quality is or how much goo is in there (and it's not a reflection on tube quality).

-1 fail

A tire blowout can be caused by a pinched tube. A tire blowing off the rim CAN be a tube problem. In addition to being a rim or tire problem.

If you aren't running steel rims or old steel rims, it's highly likely that it's the tube or the tire. Usually tube. Tire failure is completely obvious upon inspection

ahh... the mysteries of life.

I never said anything about 140....



Anyway....I took the tube out this evening and found that it blew on the rim side, right in the center of the tube, near the valve stem. If it was pinched would it blow at the point where it was pinched or someplace else? It was so close to the valve stem it seems like it would be impossible to be pinched in that spot.

Sometimes it just happens. I've had the tube in my front wheel go off in the car simply because the front tire found a way to unbead itself.