Valve Extender Woes

[Justin F. Knotz]

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 [email protected] http://www.shampoo.ca

 

[Justin F. Knotz]

<quote who= Justin F. Knotzke [email protected]/>:
> 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 [email protected] 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" <[email protected]> wrote in message
news:[email protected]...
> 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 [email protected] http://www.shampoo.ca

 

[Phil Holman]

"Justin F. Knotzke" <[email protected]> wrote in message
news:[email protected]...
> <quote who= Justin F. Knotzke [email protected]/>:
> > 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" <[email protected]> wrote in message
news:[email protected]...
> 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 [email protected] http://www.shampoo.ca

 

[Ant]

"Tom Kunich" <[email protected]> wrote in message
news:<F8W%[email protected]>...
> 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. Knotz]

<quote who= Tom Kunich [email protected]/>:

> 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 [email protected] 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" <[email protected]> wrote in message
news:[email protected]...
> <quote who= Tom Kunich [email protected]/>:
>
> > 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 [email protected] http://www.shampoo.ca

 

[Justin F. Knotz]

<quote who= Tom Kunich [email protected]/>:
> 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 [email protected] http://www.shampoo.ca