countyquest

Hi everyone
I'm having problems with flats with cut stem bases. I do my best to keep them straight, keep my tires aired up properly. If I notice the stem going angled, I stop to deflate, straighten, and inflate. It is happening on nearly every trip. (It is only happening on the front tire.)
Should I drill the hole bigger, or is there another root cause that is making the tube rotate in the rim? It's driving me NUTS.

531Aussie

I wrap some cloth sticky tape around the base of the valve stem which acts as a stopper, preventing the valve moving around, and also stops it pulling through the hole and tearing.

madpogue 

Maybe the tube is for a narrower tire, and is thus not filling the cavity as well as it should? Just a thought. Maybe the tube's for a smaller diameter tire (26" tube in a 700 rim/tire, e.g.)?

yak

Assuming that you are maintaining the correct tire pressure (and it's a schrader valve), you could consider using presta valved tubes, which have a thread all the way own the valve stem, with a ring that you can thread down.

Raiyn

Continental makes schrader tubes that have a lock nut just like a presta tube. If nothing else that valve will NOT move.

countyquest

Thanks everyone for the great help.
I found out the problem-my tire was worn out. Evidently, it had stretched and it was also turning on the rim. I figured it out when I realized that the tire was coming off the rim way too easily when I changed the flat for the third time this week.
I bought a new tire and that sucker is staying as straight as can be.
Again, thanks for your help.

MichaelW

Are you using decent rim tape. Velox cloth tape is cheap, easy to fit, lasts for years and prevents a whole range of inner-tube problems.
Also check if the the valve hole of the rim has a sharp edge. Emery cloth can take the edge off.

titlemanager

I was having the same issue. As it turns out for the same reason too. My tire was too worn out. So thank you for posting, and thank you to the wise one who came up with the proper diagnosis.

Ronsonic 

I've had this myself. The tire was dried out. I solved it with a thin wipe of tubular cement around the bead of the tire, let it dry completely (didn't want to glue it on, just add friction) and remounted it. That cured it. I'd expect almost any rubber based glue, contact cement or whatever's handy would do just as well.

Or, just buy a fresh tire like you did. But I'm cheap and I really liked that tire.

cny-bikeman

Glad you figured out the correct cause, as the solution of preventing the valve from moving is only treating the symptom, and may not prevent a flat. If the root cause is not addressed the tube will continue to migrate, eventually stretching the area around the base of the valve stem enough so that the tube tear and still fail.