Valve Extender Woes

[Justin F. Knotzke]

Hi,

I own a pair of Tubular Zipp 404s. The back wheel has a Zipp valve
extender. The front has some generic extender.

I have had to take the tubular off 3 times now because after 3 or 4
pump ups the valve closes itself. When I take the tire off sure enough
the valve has screwed itself closed.

I am going to buy another Zipp made valve extender in hopes that
fixes it.

Could anyone shed some light on why this valve keeps screwing itself
closed? Its very annoying to arrive at a race and realize that I
can't pump up my favorite wheels.

Thanks

J


--
Justin F. Knotzke

http://www.shampoo.ca

[Justin F. Knotzke]

<quote who= Justin F. Knotzke />:
> Hi,
>
> I own a pair of Tubular Zipp 404s. The back wheel has a Zipp valve
> extender. The front has some generic extender.

Just to clear a few things up. The problem is only with the front
wheel and not the back. The back wheel has never given me problems.

Thanks

J

--
Justin F. Knotzke

http://www.shampoo.ca

[Bruce]

It's not the valve extender, but the tire's valve endnut and threads.
Before you put on the valve extender ensure that the endnut will not
rescrew. Stop the endnut from turning. One way to do that is to damage the
threads so it won't turn. Another is to pinch the endnut so it is too tight
on the threads.

-Bruce

"Justin F. Knotzke" > wrote in message
...
> Hi,
>
> I own a pair of Tubular Zipp 404s. The back wheel has a Zipp valve
> extender. The front has some generic extender.
>
> I have had to take the tubular off 3 times now because after 3 or 4
> pump ups the valve closes itself. When I take the tire off sure enough
> the valve has screwed itself closed.
>
> I am going to buy another Zipp made valve extender in hopes that
> fixes it.
>
> Could anyone shed some light on why this valve keeps screwing itself
> closed? Its very annoying to arrive at a race and realize that I
> can't pump up my favorite wheels.
>
> Thanks
>
> J
>
>
> --
> Justin F. Knotzke
>
> http://www.shampoo.ca

[Phil Holman]

"Justin F. Knotzke" > wrote in message
...
> <quote who= Justin F. Knotzke />:
> > Hi,
> >
> > I own a pair of Tubular Zipp 404s. The back wheel has a Zipp
valve
> > extender. The front has some generic extender.
>
> Just to clear a few things up. The problem is only with the front
> wheel and not the back. The back wheel has never given me problems.

Make sure the valve is screwed all the way out and is tightened against
the end bulge.

Phil Holman

[Tom Kunich]

I don't know what your valve extender is like but the Campi ones I use
work as follows: You remove the valve extender, turn it around,
reinsert it into the wheel and unscrew the filler. pro[perly
reinstalling the extender I pump up the tire. Then I pull the extender
off and retighten the filler.

I've had wheels go flat fron slow leads around the filler when it was
left unlocked.


"Justin F. Knotzke" > wrote in message
...
> Hi,
>
> I own a pair of Tubular Zipp 404s. The back wheel has a Zipp
valve
> extender. The front has some generic extender.
>
> I have had to take the tubular off 3 times now because after 3 or
4
> pump ups the valve closes itself. When I take the tire off sure
enough
> the valve has screwed itself closed.
>
> I am going to buy another Zipp made valve extender in hopes that
> fixes it.
>
> Could anyone shed some light on why this valve keeps screwing
itself
> closed? Its very annoying to arrive at a race and realize that I
> can't pump up my favorite wheels.
>
> Thanks
>
> J
>
>
> --
> Justin F. Knotzke
>
> http://www.shampoo.ca

[ant]

"Tom Kunich" > wrote in message t>...
> I don't know what your valve extender is like but the Campi ones I use
> work as follows: You remove the valve extender, turn it around,
> reinsert it into the wheel and unscrew the filler. pro[perly
> reinstalling the extender I pump up the tire. Then I pull the extender
> off and retighten the filler.
>
> I've had wheels go flat fron slow leads around the filler when it was
> left unlocked.
>

yep. a few presta valves ive put under water looking for leaks blow
some pretty serious bubbles when the endnut (new term for me) isnt
screwed down tightly. I previously thought they wouldnt leak here, but
now i know.

anthony

[Justin F. Knotzke]

<quote who= Tom Kunich />:

> I don't know what your valve extender is like but the Campi ones I use
> work as follows: You remove the valve extender, turn it around,
> reinsert it into the wheel and unscrew the filler. pro[perly
> reinstalling the extender I pump up the tire. Then I pull the extender
> off and retighten the filler.

The valve extender I use simply screw on the original valve. I then
have to put the valve and extender through the rim. The nut to the valve
has to stay open.

I have noticed that after a week the tires are flat. But I've
never noticed anything during an actual race. Now that you bring this up
though...

I think I might try those valve core extenders.

http://www.tniusa.com/products/valveextenders.html

No idea how they work but my current setup clearly isn't working for
me.

J


--
Justin F. Knotzke

http://www.shampoo.ca

[Tom Kunich]

The problem with the extenders I've been using is that they don't
properly fit the pump and tend to stretch the rubber seal out. These
things you've shown look interesting and I'd like to try them. Let us
know how they work.



"Justin F. Knotzke" > wrote in message
...
> <quote who= Tom Kunich />:
>
> > I don't know what your valve extender is like but the Campi ones I
use
> > work as follows: You remove the valve extender, turn it around,
> > reinsert it into the wheel and unscrew the filler. pro[perly
> > reinstalling the extender I pump up the tire. Then I pull the
extender
> > off and retighten the filler.
>
> The valve extender I use simply screw on the original valve. I
then
> have to put the valve and extender through the rim. The nut to the
valve
> has to stay open.
>
> I have noticed that after a week the tires are flat. But I've
> never noticed anything during an actual race. Now that you bring
this up
> though...
>
> I think I might try those valve core extenders.
>
> http://www.tniusa.com/products/valveextenders.html
>
> No idea how they work but my current setup clearly isn't working
for
> me.
>
> J
>
>
> --
> Justin F. Knotzke
>
> http://www.shampoo.ca

[Justin F. Knotzke]

<quote who= Tom Kunich />:
> The problem with the extenders I've been using is that they don't
> properly fit the pump and tend to stretch the rubber seal out. These
> things you've shown look interesting and I'd like to try them. Let us
> know how they work.

I picked up a box yesterday. They are made by Vittoria, came two in a
box for $22CDN. Rather cool idea. The Vittoria tubulars I have are able
to unscrew just below the nut and the core extenders come with a little
plastic tool that makes removal very easy.

http://www.worldclasscycles.com/valve_extension_31_mm.htm

The above URL shows fairly well how it works. If you look at the
first image you will see the nut and its threaded body followed by the
extender followed by the rest of the valve.

Slid the whole mess into the Zipp 404 and realized that I probably
didn't buy a long enough extender. Mine actually sticks out to about
what image 2 is here:

http://www.worldclasscycles.com/valve_extender_sizing.htm

But I figured rather then bring it back to the LBS I'll just screw a
regular extender on that, pump up the tire and then take off the
extender and tighten the nut. It looks better I suppose and does what I
need it to do.. I am actually able to pump up the tire without this last
extender but I have to hold the chuck in place..

But it seems to be working fine.

J.


--
Justin F. Knotzke

http://www.shampoo.ca