Singlespeed & Fixed Gear - Tire spontaneously loses air?

Sitting here in my apartment at about 2am, and out of nowhere I hear the telltale pffffffffft of a tire losing pressure. I check my bike on the other side of the room, and sure enough my rear tire has lost all pressure.

Last ride was a mild one, quick errand maybe a mile or so. I did hop down a curb on the way home, but if that damaged the tire or tube wouldn't the effects have been sooner?

Tire and tube are the stock components from my IRO Mark V, purchased in July of 08. I pribably last filled with air 6 days ago at 120psi. Not a huge deal, just weirded me out to that the tire completely lost pressure seemingly out of nowhere. Haven't tried refilling yet, but should I just go ahead and replace that rear tube?

did you take out the tire, blow it up, and put it into water to check for air bubbles?

If you look closely at the tire, you might find a puncture. You can either patch the tube or if it is old, replace the tube completely. Also, check for remnants of the thorn/glass, etc. on the inside of the tire before inflating the tube.

had this happen to me before. turned out to be a small puncture somewhere along the ride that didn't spew air until 10ish minutes after i stopped

Also check your rim strip to see if a nipple is poking through and to see if all holes are covered.

I suspect a leak at the valve stem base.

Consider yourself lucky. Last night I damn near had a heart attack. I opened my balcony door and BOOM!!! It sounded like a gunshot went off in my apartment. After checking that my gun hadn't actually gone off, I looked at my freshly deflated tire. It blew the tire off the rim. Needless to say I had to take the bus this morning because I'm fresh out of tubes.

i'm with min...bad/misplaced rim strip or too long spoke.

and to the prior poster...your tire wasn't properly seated in the rim bead. recent service back there?

I suspect a leak at the valve stem base.

This. I had the same thing happen to my bike for no apparent reason when I first brought my bike home from the shop, hadn't even taken it out for a proper ride yet. I was walking it out the door and PSSHHHH. Took the tube out and there was a hole right at the base of the valve stem.

ok, here is the as close to the awful truth as i can assume from your story. it wasn't a spoke and it was not spontaneous. you said you pumped up your tube to 120 psi 6 days ago and obviously you have been on your bike out and about town in those 6 days. Tubes loose air pressure over time and more if you ride on it, you probably lost some psi and just got a pinch flat when you jumped the curb.

and to the prior poster...your tire wasn't properly seated in the rim bead. recent service back there?

No. Don't get me wrong, I'm not at all surprised that it happened. It's the original rim that came on the bike, I assume since I bought it used, and the tire is definitely not new. I just pumped the tube up too high for that combination of oldness. Too poor at the moment to afford a new rim or tire. Just have to watch my pressures.

"Spontaneity is the spice of life."

-sp00ki, others

So this morning I went ahead and tried to fill the tire up and sure enough, I could hear a major leak. I take a look and find a good 7mm or so tear on the surface of the tire opposite the valve stem. Went ahead and replaced the whole thing with a 25c gatorskin at the lbs. Way overpriced compared to pbk, but they're a friendly shop.