Mysterious flat...

[Eden]

if you can find no holes, it could be a broken/leaky valve

[spokewench]

You undoubtedly have at least what you call a "Slow Leak". Sometimes, they are slow enough that they don't bother you while you are riding but left over night or a a couple of days and the tire will be flat.

There is something causing this, so you should probably try putting it in water to find the telltale bubbles where it is leaking. Fill the tube with air, put it in a bucket and squeeze on the tube to find the bubbles if they are not apparent right away.

My hubby has been known to ride for miles on Slow Leak tires (he airs them up before he leaves each time). Me, I just find the leak and patch it or change to a new tube.

spoke

[BleeckerSt_Girl]

I had the same thing happen this weekend. Turns out there was a slow leak where the valve connects to the rubber tube. It didn't leak unless I tilted the valve slightly. It showed up in the underwater treatment. Had to throw the tube out. Probably happened while tilting the valve out to fix a puncture in the tube.

[steinspinne]

Thanks to everyone for the suggestions! I tried the underwater treatment, and found that there was a not so small rip where the valve stem connects to the tube. It didn't leak unless I moved the stem, but when I did it was flat within seconds. Ran to the LBS to catch them before close and got a new tube.

Thanks for the help!

[BleeckerSt_Girl]

Yep, that's exactly how mine was! Didn't leak unless I moved the valve stem a bit.

Hey, you might want to have more than just one spare tube on hand....things happen.

[SouthernBelle]

Ditto the extra tubes. My LBS will throw the 5th free.

[velogirl]

the area where the stem connects to the tube is one of the most fragile areas of the tube. here are some hints that will help you prevent future flats in that area:

1) don't use the little washer to "pull" the stem out of the rim.

2) if you have to use the little washer because of a combination of deep dish rim and short stem, don't tighten it too much.

3) when removing the tube from the tire, always start at the section opposite the stem. when you reach the stem, you'll be able to just pull it away from the rim without putting excess pressure on the stem area.

4) always handle your stem gingerly when pumping your tire. make sure it's perpendicular to the rim. don't pull or tug. treat it like the fragile flower it is!

hope this helps!