Ok, that's it.

[Meg McKilty]

I give up, for serious yo's.

SouthernBelle and I have now gone through three tubes and two tires. My front tire utterly refuses to stay inflated.

We had both of us trying it out- changing the tubes, then the tire, and yesterday we thought we had it fixed until it went flat on me. On hill day. On a main part of town with lots of traffic at night.

What to do? I have ordered a new tire (the brand new one on it the first time really is defective) and the other one should be fine.

We've checked sizing, puncture possibilities, and wondered if the wheel is bent. It was just trued two weeks ago!!

[teigyr]

The bike hates you?!

Seriously, ok. You checked for punctures and there were none? How is the air leaving the tube? Did you do all the normal "inflate & put in a bucket of water" stuff? What about something poking near where the thingie goes out of the hole (sorry, am blanking but you know what I mean hopefully!). Valve. That's it.

I know there are people who know far more than me but from breaking it down in a troubleshooting sort of way...the tube is losing air somehow. It's a question of how and where - ie is the rim digging in? Or is there a pinch flat? Or a batch of defective tubes? Thorn through the tire? Probably not that though if you changed the tires. Or maybe someone's messing with you when you aren't looking?

Curious.

[Blueberry]

Feel around the rim to make sure your rim tape completely covers all the little holes - they can be sharp. Also feel around the valve stem hole. DH had a flat problem for a while until we discovered a little metal burr there. Inflate the blown out tubes under water to see where the hole is - that should give you an idea of where the problem on the wheel is.

[DebW]

That's tough luck. Have you been able to locate the leak in every flat tube? Are they on the outside (road side) or inside (rim side)? Are they pinch flats with 2 holes like a snakebite? Is the rimstrip old? If you can locate the leak, you can often determine the cause and hopefully prevent future flats of the same type. But sometimes it's confounding.

[mimitabby]

how much air are you putting into the tires?

My DH put 120 lbs of air into the tires for my hybrid and I got flats 2 days in a row. the second day I noticed that the poor tube had been trying to squeeze through the spokes holes.
THen I asked him how much air he was putting in. I think max for those tires was 70lbs.
that solved that problem.

[Grog]

I support the rim hypothesis.

My sweetie had lots of flats and I got sick of waiting on the side of the road. I grabbed the wheel, pulled off the tire and inspected the rim. The tape was all over the place, not protecting the tube at all. I rearranged the tape temporarily and then he got new rim-covers (sort of a latex band, instead of simple tape...).

[Meg McKilty]

No, no, no. We checked it all.

The tire, the tubing, no tire wall pinching the tubing, one flat was near the valve, the other simply blew (and my ears ached for several minutes),a nd no this one refuses to stay inflated for more than about an hour. I can only imagine how long I was riding on a flat yesterday.

The tires can hold 87-120 psi. We usually put about 100 in, but we put 90 in it just to see. Seemed stable until later in the ride.

Now, I haven't gotten to the water and bucket thing- lazy American?

[Grog]

Another silly thing I can think of:

a bad batch of tubes.

Or just plain bad luck.

[CyclaSutra]

I had six flats in one spring until I got my rim tape re-taped... one shop just re-installed the same old tape. First a hit-the-rock blowout of the tire off the rim and then... Two more flats. So I went to a different shop and whined until they put new rim tape on AND THEN put ELECTRICAL TAPE over the rim tape. Double protection against those nasty spoke holes. Few hundred/about a thousand miles, no more flats. I now strap duct tape on all my seat posts for emergency cover-the-spoke-hole incidents.

Sometimes it's just bad luck, sometimes it's figuring out a pesky mystery. Good luck!!!