Q- tube slow leak



S

Steve

Guest
Hi.

Road bike, presta valve, rear wheel. Doing more riding lately.

The rim hole is causing a slow leak in my tubes- the edge of the rim hole is
repeatedly cutting into the base of the valve rubber- I'm going through lots
of tubes.

Should be an easy way to fix this? There's no noticably sharp edges. There's
also nothing but bare rim touching the valve- the rim tape stops short of
the hole.

Any suggestions?
 
A

A Muzi

Guest
Steve wrote:
> Road bike, presta valve, rear wheel. Doing more riding lately.
> The rim hole is causing a slow leak in my tubes- the edge of the rim hole is
> repeatedly cutting into the base of the valve rubber- I'm going through lots
> of tubes.
> Should be an easy way to fix this? There's no noticably sharp edges. There's
> also nothing but bare rim touching the valve- the rim tape stops short of
> the hole.
> Any suggestions?


Some brands of tube are notorious for valve problems. If the metal valve
assembly is pulling out of the molded rubber base, change brands.

Are you installing the little threaded ring on your valve? Don't. While
useful for fat tire applications to keep the valve from falling inside
when starting to pump, it's easy to overtighten the ring.

Lastly, are you using the fattest tube possible? Skinnier tubes in wider
tires will also fail near the valve where the tube is less elastic.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
 
S

Steve

Guest
"A Muzi" <[email protected]> wrote in message
news:[email protected]
> Steve wrote:
> > Road bike, presta valve, rear wheel. Doing more riding lately.
>>


Andrew, thanks for the pointers. No more overtightening the little threaded
ring for me. Also I put a tape patch (rim tape)over the hole- will see if
that works.

Thanks again.
Steve
 
M

Michael Press

Guest
In article <[email protected]>,
A Muzi <[email protected]> wrote:

> Are you installing the little threaded ring on your valve? Don't. While
> useful for fat tire applications to keep the valve from falling inside
> when starting to pump, it's easy to overtighten the ring.


It is impossible to over-tighten that nut. Here is the experiment:

* Install a tube.
* Tighten the ring nut on the threaded valve stem tightly.
* Inflate the tire to 6 or 7 bar.
* Examine the ring nut. Typically it is loose.

--
Michael Press
 
A

A R:nen

Guest
Michael Press <[email protected]> writes:

> It is impossible to over-tighten that nut. Here is the experiment:


> * Install a tube.
> * Tighten the ring nut on the threaded valve stem tightly.
> * Inflate the tire to 6 or 7 bar.
> * Examine the ring nut. Typically it is loose.


Your experiment doesn't go all the way, here's the continuation:

* Retighten the nut.
* Deflate the tire.
* Examine the ring nut. It should be way too tight.

Of course, tightening the nut when the tire is inflated is where
things go wrong, but I'd say it's a rather common mistake.
 
M

Michael Press

Guest
In article <[email protected]>,
[email protected] (A R:nen) wrote:

> Michael Press <[email protected]> writes:
>
> > It is impossible to over-tighten that nut. Here is the experiment:

>
> > * Install a tube.
> > * Tighten the ring nut on the threaded valve stem tightly.
> > * Inflate the tire to 6 or 7 bar.
> > * Examine the ring nut. Typically it is loose.

>
> Your experiment doesn't go all the way, here's the continuation:
>
> * Retighten the nut.


No need to retighten. By being their
if fulfills its function.

> * Deflate the tire.
> * Examine the ring nut. It should be way too tight.
>
> Of course, tightening the nut when the tire is inflated is where
> things go wrong, but I'd say it's a rather common mistake.


--
Michael Press