Just zis Guy, you know? wrote:
On Sep 14, 8:18 am, "Doki" wrote:
I keep getting punctures on my mountain bike, where the Schraeder
valve has been pulled off the tube. Clearly, the tyre is rotating
slightly on the rim under braking, and pulling the tube along with
it, which eventually rips the valve off.

Tyres are 2.25" Panaracers, running at a fairly low pressure, and
are well within the maximum specs for the rim (I think the max is
2.5"). I don't want to increase pressure, unless I really have to.

Any ideas on possible remedies? I don't really want to superglue the
tyres to the rim... The tyres are also about 4 years old, if that
makes any odds.

Do the valves have threaded stems with retainers on them or are they
just pushed in?

I've had both kinds, and done it to both.