I went out on a ride today and there is a new subdivision going up on the route. I stupidly decided to spin through it just to see it (lots of construction with the inevitable crap on the road). I hit something (sounded like a strip of metal but I never saw it) and then I heard a gentle, almost soothing "SHHHHHHHHHHHHHH...." as the air left my rear tire (why is it always the rear).

I still ride butyl tubes and after removing the tube I pumped a bit of air into the tube to see where the leak was so I could check the wheel carefully in that area. Couldn't find a leak so I just replaced the tube and rode home (close to the end of the ride anyway).

I pumped the tube up with a good bit of air after getting home and it held air just fine. I forced it into a bucket of water and the only air bubbles that I saw were just a few coming from the presta valve stem - those went away when I closed the valve. I honestly cannot say for sure that the valve was closed on the ride. I don't know if this tube will hold 90 pounds of air when encased in a Conti tire, but it certainly holds low pressure just fine.

So either this tube has a high pressure only leak (it was DEAD FLAT) when I removed the tube, or something funky happened regarding the valve/stem. No big deal other than I would prefer to fix and reuse the tube. I just have no idea what to fix.

Thoughts on what happened here? Thanks.

dave