Smaller tubes should not slide in the tire. Tubes do a pretty good
job of expanding to fill the space available. Usually the cause for
stem failure is that the tire was underinflated and spun on the rim,
the tire slid on the mounting lubricant, if you used any, the tire
was not seated properly or it was damaged in the mounting process.
There are acceleration and braking forces trying to spin the rear
tire and braking forces that work to spin the fronts. Just for the
hellofit put a mark of some sort on the rim and tire to see if the
tire is sliding.
--- In
DSN_KLR650@yahoogroups.com, Jacobus De Bruyn
wrote:
>
> I had two flats in four days, the valves seemed to
> have ripped out of the tubes. One front, one back.
> I was mystified, but after sleeping on it, I have the
> feeling that it could be this:
> Often I cannot get here the tubes I need, so I settle
> for tubes that are too small, like 400, or 300 for the
> front.
> I had the feeling that perhaps because of this, the
> tire is not pressed well against the rims, and could
> slide a bit, causing stress on the valves in the inner
> tube.
> How about this reasoning, people that know? Anyhow,
> the tubes have lasted six months rear and more than
> one year front. I am switching to heavy duty tubes
> from Fred, not so easy to get inside the tire, but
> probably worth the effort and the price.
> You who know, share your wisdom, so we all get wiser. Jacostarica.
>
>
>
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