Presta valves?

Quoted message said:

I looked around and I can't seem to find out if you can replace a
presta valve.

Usually not replaceable. Schwalbe is one exception: their Presta tubes have
replaceable valve cores - the middle bit unscrews. They're good tubes
generally as well. (Gearshift have them on special offer).

Quoted message said:

The small nut on a stem had broken off the last time I removed my air
pump but the pressure held.

When I went to fill it again, it filled, but then all the air
evacuated when I removed the pump.

Can I unscrew this and somehow just replace the valve and not the
whole tire? I don't see an obvious place to undo it.

Inner tube, you mean. Probably can't undo the valve core if you can't see
any flats where a tool could be used.

You've had a rare problem. Hopefully won't happen again if you're more
careful with your pump & pumping. No need to unscrew the nut right to the
end.

The nut can be screwed back on if that just came off rather than anything
being actually broken.

~PB

Quoted message said:

I looked around and I can't seem to find out if you can replace a presta
valve.

The small nut on a stem had broken off the last time I removed my air pump
but the pressure held.

When I went to fill it again, it filled, but then all the air evacuated
when I removed the pump.

Can I unscrew this and somehow just replace the valve and not the whole
tire? I don't see an obvious place to undo it.

TIA

Unless you have a replacable valvecore (look for two wrenchflats on the
thread for the valvecap) the tube is shot *)

*) the next poster will probably explain 'How-I-glued-a-valve-
from-an-old-tube-on-my-tyre-in-less-than-three-hours" or " proper-valves
were-not-glued-but-screwed-in"

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

The alternative is to but another valve, normally about 4 quid. Problem is
that it comes with a tube attached!!

SW

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

Quoted message said:

I looked around and I can't seem to find out if you can replace a presta
valve.

The small nut on a stem had broken off the last time I removed my air pump
but the pressure held.

When I went to fill it again, it filled, but then all the air evacuated
when I removed the pump.

Can I unscrew this and somehow just replace the valve and not the whole
tire? I don't see an obvious place to undo it.

TIA

In article <[email hidden]>

Quoted message said:

I looked around and I can't seem to find out if you can replace a presta
valve.

Sometimes - the replaceable ones tend to have a chromed valve core
screwed into a brass stem, with two obvious flats to grip the core.

Quoted message said:

The small nut on a stem had broken off the last time I removed my air pump
but the pressure held.

You need to support the pump firmly when using it - it's generally
excess movement that persuades the plunger to break.

Quoted message said:

When I went to fill it again, it filled, but then all the air evacuated
when I removed the pump.

If you find yourself in the same situation again make sure that the
valve stem is pointing vertically downwards, so the plunger stands a
good chance of falling back into place rather than disappearing inside
the tube.

Quoted message said:

Can I unscrew this and somehow just replace the valve and not the whole
tire? I don't see an obvious place to undo it.

You'll only need to replace the tube, not the tyre.

In article <[email hidden]>
M-gineering <[email hidden]> wrote:
<snip>

Quoted message said:

*) the next poster will probably explain 'How-I-glued-a-valve-
from-an-old-tube-on-my-tyre-in-less-than-three-hours" or " proper-valves
were-not-glued-but-screwed-in"

I remember them - people used to unscrew the nut that held the valve in
the tube when they fitted it, then wonder why the tyre kept going down.

Rob Morley said:

Quoted message said:

*) the next poster will probably explain 'How-I-glued-a-valve-
from-an-old-tube-on-my-tyre-in-less-than-three-hours" or " proper-valves
were-not-glued-but-screwed-in"

I remember them - people used to unscrew the nut that held the valve in
the tube when they fitted it, then wonder why the tyre kept going down.

In my day we used to make our own tubes from eel skins sewn together
with goat hair

On 12/13/2006 18:32:10 said:

I looked around and I can't seem to find out if you can replace a presta
valve.

Quoted message said:

The small nut on a stem had broken off the last time I removed my air pump
but the pressure held.

Quoted message said:

When I went to fill it again, it filled, but then all the air evacuated
when I removed the pump.

Quoted message said:

Can I unscrew this and somehow just replace the valve and not the whole
tire? I don't see an obvious place to undo it.

Quoted message said:

TIA

The yop of the valve usually unscrews from the valve but getting spares can be a pain.

--

Buck

I would rather be out on my Catrike

http://www.catrike.co.uk

On 12/14/2006 13:02:58 Buck said:

On 12/13/2006 18:32:10 [email hidden] wrote:

Quoted message said:

Quoted message said:

I looked around and I can't seem to find out if you can replace a presta
valve.

Quoted message said:

Quoted message said:

The small nut on a stem had broken off the last time I removed my air
pump but the pressure held.

Quoted message said:

Quoted message said:

When I went to fill it again, it filled, but then all the air evacuated
when I removed the pump.

Quoted message said:

Quoted message said:

Can I unscrew this and somehow just replace the valve and not the whole
tire? I don't see an obvious place to undo it.

Quoted message said:

Quoted message said:

TIA

Quoted message said:

The yop of the valve usually unscrews from the valve but getting spares
can be a pain.

Actually, ignore this, I only use Schwalbe tubes in the trikes and these are servicable, I looked a a couple of customer bikes in for service and non of their tubes are servicable.
--

Buck

I would rather be out on my Catrike

http://www.catrike.co.uk

Buck said:

The yop of the valve usually unscrews from the valve but getting
spares can be a pain.

If you mean the valve core, it's doesn't /usually/ unscrew with the average
inner tube found in the UK nowdays.

~PB

On 12/14/2006 13:27:40 'Pete Biggs said:

Buck wrote:

Quoted message said:

Quoted message said:

The yop of the valve usually unscrews from the valve but getting spares
can be a pain.

Quoted message said:

If you mean the valve core, it's doesn't /usually/ unscrew with the
average inner tube found in the UK nowdays.

Quoted message said:

~PB

Beat you to it. 🙂

--

Buck

I would rather be out on my Catrike

http://www.catrike.co.uk