Iner tubes splitting at valve

news.freeserve.net said:

I have now got through four tubes by splitting near the valve when i pump it up. why does this
keep happening?

This could be because either the valve hole is slightly too large or the edge of the hole is sharp.
I suffered the same but made a washer out of some old rubber and put it over the valve stem. No
trouble since.

John B

"news.freeserve.net" <[email hidden]> wrote in message
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Quoted message said:

I have now got through four tubes by splitting near the valve when i

pump it

Quoted message said:

up. why does this keep happening?

Apart from any other possible causes, some tubes can be faulty and have weak valve to tube bonding.
Try a different brand, and try doing without valve lockring if using one (just in case being
over-tightened and pulling tube down too far, etc).

~PB

I used to get this, due to my inability to keep the push-on type of pump still while pumping. I
solved it by going back to the old type of pump with connecting tube, but there are those who say
they can't get enough pressure with them. I also have a "pneuforce" pump, which has a long
connecting tube, and a clip at the bottom end which you clip onto your frame, thus giving you
something to pump against, allowing higher pressures. This one is brilliant. I don't know if it is
still available, though.

--

Martin Bulmer "Mixless Foot Persuasion"

"news.freeserve.net" <[email hidden]> wrote in message
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Quoted message said:

I have now got through four tubes by splitting near the valve when i pump

it

Quoted message said:

up. why does this keep happening?

John B <[email hidden]> wrote: ( "news.freeserve.net" wrote: ) > I have now got through
four tubes by splitting near the valve when i pump it ( > up. why does this keep happening? ) I
suffered the same but made a washer out of some old rubber and put it over ( the valve stem. ) No
trouble since.

My idiosyncrasy in this area is to use a second lock-ring inside the rim. I've never been happy with
the idea of pinching the rim between a lock-ring on the outside and the bit of (rubber) weld that
the valve base sits in, so I keep lock rings from old tubes and fit one inside the ring. The
superstition is that the old one goes inside because the knurled bit on new ones feels as though it
has sharp edges...

Thus spake "Pete Biggs" <[email hidden]>

Quoted message said:

"news.freeserve.net" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I have now got through four tubes by splitting near the valve when i

pump it

Quoted message said:

up. why does this keep happening?

Quoted message said:

Apart from any other possible causes, some tubes can be faulty and have weak valve to tube
bonding. Try a different brand, and try doing without valve lockring if using one (just in case
being over-tightened and pulling tube down too far, etc).

Some batches of Specialized tubes seem to have been very bad. I don't know if it was the bonding, or
that the rubber at the base of the valve stem was very weak. Certainly, this alone justified my
habit of regularly checking 'spare' inner tubes by inflating them and passing them under water.

--
Helen D. Vecht: [email hidden] Edgware.

"Geraint Jones" <[email hidden]> wrote in message
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Quoted message said:

My idiosyncrasy in this area is to use a second lock-ring inside the rim.

I too have done this on the advice of my LBS.

Re. not being able to keep the pump steady: I was impressed when I saw someone use a Top Peak
Mountain Morph, this is like a mini track pump with a single flip down foot rest and a retractable
hose, not cheap though.

Pete

In article said:

Certainly, this alone justified my habit of regularly checking 'spare' inner tubes by inflating
them and passing them under water.

The mind boggles:-)

--
T h e - e x t e n d e r ! ! ! !

news.freeserve.net said:

I have now got through four tubes by splitting near the valve when i pump it up. why does this keep
happening?

I have had this problem with my daughters old bike. I eventually found out that I was using presta
tubes on rims that were drilled out for Schraeder (sp?) valves - which are slightly bigger. The
bigger hole was allowing the smaller presta valve to "pop out"

does that make any sense at all?

John T. Remove the singers of Spam before replying

I was having the same trouble with my road rims until I bought a floor pump. I figure that using a
hand pump (or frame pump) wiggles the stem too much when I pumped it. Havent had any problems in the
last year since I started using a floor pump with a locking head (they all have one now). I use to
go through a tube every couple weeks the old way. A cheap Topeak JoBlow is quite good at £29 and
pumps up to 120psi easily.

hope this helps...

"Sandy Morton" <[email hidden]> wrote in message
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Quoted message said:

In article <[email hidden]>, Helen Deborah Vecht

Quoted message said:

Certainly, this alone justified my habit of regularly checking 'spare' inner tubes by inflating
them and passing them under water.

The mind boggles:-)

--
T h e - e x t e n d e r ! ! ! !

news.freeserve.net said:

I have now got through four tubes by splitting near the valve when i pump it up. why does this keep
happening?

Hi Michael

I've suffered similar troubles twice in the past. The sticky out bit of the valve assemblies
literally fell off from two tubes, both of which were bought from Halfords.

James

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