Hi. I had brought my back wheel to the LBS to get trued. While it was there, the LBS told me that the tire was particularly worn, and needed replacement. While I was going to get one of the internet and do it myself, they had a very good deal on a Michelin Pro Race, so I just let them replace it, with a new tube as well.

Anyway, not more than two or three rides after they replaced tire/tube, I had a flat. I figured I had just hit. I didn't have a patch kit or tools on me (i wasn't far from home), so I walked it back home. Unfortunately on my way back I became stuck in a severe thunderstorm w/ torrential winds and downpours. But that is a different story.

Bah, I digress. Anyway, I noticed that the flat was caused by a severed valve. When I tried lightly inflating the tube beforehand, somehow the pressure caused the valve to completely detach from the tube.

So this most likely was not the cause of a impediment i hit, but rather a defect in the tube, or perhaps the LBS putting on the tube wrong. I've put on enough myself to know that if the valve is at too much of an angle, it can put a lot of pressure on it, causing it to tear. What do you guys think?

I don't really care one way or the other, tubes only cost $5, but it would be nice to know what happened. Like any true patriotic, god-fearing American, I must find someone to blame other than myself.

That sounds like a defect to me. I've learned one blown tube right after you change a tube/tire usually is a fluke/weird pinch or defective tube.

Duh. Blame the French.

If you must, blame someone else. However, you might have damaged it removing the head of your pump from the valve. If you didn't pump it up, perhaps the person at the LBS damaged it.

Don't you mean Canada?

I would chalk that one up as bad luck. If the problem persists you may consider adding some rim tape (a layer of electrical tape should do the trick as well) around the valve hole, particularly if it is sharp. It's not usually a bad idea, regardless.

Likely just a bad tube, it happens unfortunately.

Could also be poor form. Some people just yank the pump head off the valve stem. I lightly lube the pump head about once a month or so, when removing the pump head gets a little sticky. You should also pinch the valve stem with your other hand with either a presta or scharder valve.

The shop mechanic could have done this, you could have done this, or it was really a bad tube.

We all know it's George W Bush's fault.

I'll settle for French Canadians. C'est bon?

It maybe an unlucky fault in a $5 tube but being an American it's you duty to sue them for $1 billion.