valve trouble

Grrr!!! It has happened again.
For some reason my floor pump doesn't like
the valve stems on my favorite tires,
Vittoria Corsa CX. About half the time,
the valve head gets pushed back into
the tube instead of entering cleanly into
the pump head. This only seems to happen
with these tires, non other. But it's more than a
nuisance, because if it happens often enough,
the tube is weakened and begins to leak.
Since these tires are sewups, it's a major headache.

The only way I have found to prevent this from happening
is to let all the air out of the tire before pumping, so that
I can support the back of the valve with my thumb. Is this
what you are supposed to do? (Of course, these valves
aren't threaded at the bottom, so one can't use a retainer
nut to hold the valve in place.)

Arthur Ogus writes:

Grrr!!! It has happened again. For some reason my floor pump
doesn't like the valve stems on my favorite tires, Vittoria Corsa
CX. About half the time, the valve head gets pushed back into the
tube instead of entering cleanly into the pump head. This only
seems to happen with these tires, non other. But it's more than a
nuisance, because if it happens often enough, the tube is weakened
and begins to leak. Since these tires are sewups, it's a major
headache.

The only way I have found to prevent this from happening is to let
all the air out of the tire before pumping, so that I can support
the back of the valve with my thumb. Is this what you are supposed
to do? (Of course, these valves aren't threaded at the bottom, so
one can't use a retainer nut to hold the valve in place.)

That's what the little knurled nut on threaded valve stems is for.
Use it.

Jobst Brandt

On 03 Dec 2006 02:58:19 GMT, wrote:

Arthur Ogus writes:

Grrr!!! It has happened again. For some reason my floor pump
doesn't like the valve stems on my favorite tires, Vittoria Corsa
CX. About half the time, the valve head gets pushed back into the
tube instead of entering cleanly into the pump head. This only
seems to happen with these tires, non other. But it's more than a
nuisance, because if it happens often enough, the tube is weakened
and begins to leak. Since these tires are sewups, it's a major
headache.

The only way I have found to prevent this from happening is to let
all the air out of the tire before pumping, so that I can support
the back of the valve with my thumb. Is this what you are supposed
to do? (Of course, these valves aren't threaded at the bottom, so
one can't use a retainer nut to hold the valve in place.)

That's what the little knurled nut on threaded valve stems is for.
Use it.

Jobst Brandt

Dear Jobst,

The original poster wrote:

"(Of course, these valves aren't threaded at the bottom, so
one can't use a retainer nut to hold the valve in place.)"

Cheers,

Carl Fogel

Arthur Ogus wrote:
Grrr!!! It has happened again.
For some reason my floor pump doesn't like
the valve stems on my favorite tires,
Vittoria Corsa CX. About half the time,
the valve head gets pushed back into
the tube instead of entering cleanly into
the pump head. This only seems to happen
with these tires, non other. But it's more than a
nuisance, because if it happens often enough,
the tube is weakened and begins to leak.
Since these tires are sewups, it's a major headache.

The only way I have found to prevent this from happening
is to let all the air out of the tire before pumping, so that
I can support the back of the valve with my thumb. Is this
what you are supposed to do? (Of course, these valves
aren't threaded at the bottom, so one can't use a retainer
nut to hold the valve in place.)


If the pump head has a knurled nut on the face that slides on the valve
stem try slacking it off a bit to reduce the pressure on the seal washer.

HTH

Marcus

Arthur Ogus wrote:
The only way I have found to prevent this from happening
is to let all the air out of the tire before pumping, so that
I can support the back of the valve with my thumb. Is this
what you are supposed to do? (Of course, these valves
aren't threaded at the bottom, so one can't use a retainer
nut to hold the valve in place.)

Assuming you're not stopping in mid-Saskatchewan, can't you lean your
bike up against something, then put your left thumb and index finger
around the base of the valve while attaching the pump head with your
right hand? Works best when the valve is between the 7 and 9 o'clock
position. Works better with a hosed pump like a RoadMorph, too (6-8
o'clock, though.)

If these are clinchers, consider getting presta tubes that DO have
threads all the way down. If they're tubulars, can't you change valves
on those? (I haven't been close to one (other than in traffic) for
about 30 years now, but seem to recall the valves were screwed in.)

"Brian Huntley" wrote in message
ups.com...

Arthur Ogus wrote:
The only way I have found to prevent this from happening
is to let all the air out of the tire before pumping, so that
I can support the back of the valve with my thumb. Is this
what you are supposed to do? (Of course, these valves
aren't threaded at the bottom, so one can't use a retainer
nut to hold the valve in place.)

Assuming you're not stopping in mid-Saskatchewan, can't you lean your
bike up against something, then put your left thumb and index finger
around the base of the valve while attaching the pump head with your
right hand? Works best when the valve is between the 7 and 9 o'clock
position. Works better with a hosed pump like a RoadMorph, too (6-8
o'clock, though.)

If these are clinchers, consider getting presta tubes that DO have
threads all the way down. If they're tubulars, can't you change valves
on those? (I haven't been close to one (other than in traffic) for
about 30 years now, but seem to recall the valves were screwed in.)


A very long time ago there were a few - very few that came with a
partially replaceable valve. It was more trouble than it was worth and
never went anywhere. To replace the valve in a sewup, it's just like
patching one. You cut open the threads around the valve and loosen the
nut on the valve stem that secures the valve to the tube. Replace the
valve and sew it back up.

I replaced several broken sewup valve stems many years ago. After that,
I learned how to remove the pump without damaging the presta valve stem.

One other thing, apply a little saliva to the rubber grommet before
inserting the presta valve stem. A little spit goes a long way.

Chas.

On 2006-12-02 19:59:10 -0800, Marcus Coles said:

Arthur Ogus wrote:
Grrr!!! It has happened again.
For some reason my floor pump doesn't like
the valve stems on my favorite tires,
Vittoria Corsa CX. About half the time,
the valve head gets pushed back into
the tube instead of entering cleanly into
the pump head. This only seems to happen
with these tires, non other. But it's more than a
nuisance, because if it happens often enough,
the tube is weakened and begins to leak.
Since these tires are sewups, it's a major headache.

The only way I have found to prevent this from happening
is to let all the air out of the tire before pumping, so that
I can support the back of the valve with my thumb. Is this
what you are supposed to do? (Of course, these valves
aren't threaded at the bottom, so one can't use a retainer
nut to hold the valve in place.)


If the pump head has a knurled nut on the face that slides on the valve
stem try slacking it off a bit to reduce the pressure on the seal
washer.

Alas, it doesn't.

HTH

Marcus

On 2006-12-02 21:13:15 -0800, "Brian Huntley" said:


Arthur Ogus wrote:
The only way I have found to prevent this from happening
is to let all the air out of the tire before pumping, so that
I can support the back of the valve with my thumb. Is this
what you are supposed to do? (Of course, these valves
aren't threaded at the bottom, so one can't use a retainer
nut to hold the valve in place.)

Assuming you're not stopping in mid-Saskatchewan, can't you lean your
bike up against something, then put your left thumb and index finger
around the base of the valve while attaching the pump head with your
right hand? Works best when the valve is between the 7 and 9 o'clock
position. Works better with a hosed pump like a RoadMorph, too (6-8
o'clock, though.)

This is my floor pump. I don't have enough room to grip the
valve and also get the pump head on far enough.

If these are clinchers, consider getting presta tubes that DO have
threads all the way down. If they're tubulars, can't you change valves
on those? (I haven't been close to one (other than in traffic) for
about 30 years now, but seem to recall the valves were screwed in.)

The valve core screws in, but not the main body of the valve. Inded
they are tubulars.

On 2006-12-03 01:50:28 -0800, "* * Chas" said:


"Brian Huntley" wrote in message
ups.com...

Arthur Ogus wrote:
The only way I have found to prevent this from happening
is to let all the air out of the tire before pumping, so that
I can support the back of the valve with my thumb. Is this
what you are supposed to do? (Of course, these valves
aren't threaded at the bottom, so one can't use a retainer
nut to hold the valve in place.)

Assuming you're not stopping in mid-Saskatchewan, can't you lean your
bike up against something, then put your left thumb and index finger
around the base of the valve while attaching the pump head with your
right hand? Works best when the valve is between the 7 and 9 o'clock
position. Works better with a hosed pump like a RoadMorph, too (6-8
o'clock, though.)

If these are clinchers, consider getting presta tubes that DO have
threads all the way down. If they're tubulars, can't you change valves
on those? (I haven't been close to one (other than in traffic) for
about 30 years now, but seem to recall the valves were screwed in.)


A very long time ago there were a few - very few that came with a
partially replaceable valve. It was more trouble than it was worth and
never went anywhere. To replace the valve in a sewup, it's just like
patching one. You cut open the threads around the valve and loosen the
nut on the valve stem that secures the valve to the tube. Replace the
valve and sew it back up.

I replaced several broken sewup valve stems many years ago. After that,
I learned how to remove the pump without damaging the presta valve stem.

Removing isn't the problem, it's getting it on.

One other thing, apply a little saliva to the rubber grommet before
inserting the presta valve stem. A little spit goes a long way.

maybe this will work. Thanks.

Chas.

Arthur Ogus wrote:
Grrr!!! It has happened again.
For some reason my floor pump doesn't like
the valve stems on my favorite tires,
Vittoria Corsa CX. About half the time,
the valve head gets pushed back into
the tube instead of entering cleanly into
the pump head. This only seems to happen
with these tires, non other. But it's more than a
nuisance, because if it happens often enough,
the tube is weakened and begins to leak.
Since these tires are sewups, it's a major headache.

The only way I have found to prevent this from happening
is to let all the air out of the tire before pumping, so that
I can support the back of the valve with my thumb. Is this
what you are supposed to do? (Of course, these valves
aren't threaded at the bottom, so one can't use a retainer
nut to hold the valve in place.)

Dear Arthur,

You can make quick and useful tools out of cheap miniature pliers with
a file,
drill press, bench grinder, and dremel tool.

Most cheap miniature plier sets include a useless pair of flat-jaw
pliers:

http://www.harborfreight.com/cpi/cta...temnumber=4807

That kit of 5 small pliers is often on sale for $5 instead of $10. The
flat-jaw pliers are called "flat-nose" and are useless (as far as I can
tell) for anything except grabbing a very thin sheet of metal.

Grab 'em with one hand, leave the jaws slightly open, and introduce
them to a drill press, using a drill bit slightly thinner than your
smooth valve stem. The faint crack in the slightly open pliers
automatically centers the bit. Once the hole is started, squeeze the
pliers shut, and drill right through. The metal is soft enough that
this takes only a few seconds.

The jaws are more than thick enough to grab even a smooth valve stem
firmly, but thin enough that there's room for the chuck. With a hole
slightly smalIer than the valve stem (smooth or threaded), you get
4-point contact with valve stem, which is plenty. I used a handy
threaded stem of normal length for the picture, since my only smooth
valve tubes are extra-long for aero rims.

This view shows the pliers set as far as my twin-head chuck would go
onto the valve:

http://i13.tinypic.com/357gjfp.jpg

This view shows the drill bit and the hole in the pliers:

http://i13.tinypic.com/2yytqbl.jpg

With a drill press and pair of cheap pliers, it takes less time to make
the tool than to take and upload the pictures.

Cheers,

Carl Fogel