Presta Valve Annoyances

Mike McGuire said:

Does any manufacturer make tubes with a sound attachment of a presta
valve to the tube? I've been riding with them for about a year and half
now, and I've been through quite a number of tubes, all of which have
failed one way or another at the attachment of the valve to the tube.
The expense is hardly ruinous, but it is annoying. I do know about
holding head of the frame pump while inflating to keep from jerking the
valve around, so that doesn't seem to be the reason for the problem. Had
a flat today and was lucky to have two spare tubes with me. The first
spare leaked at the junction of valve and tire. It was one I had patched
before, so I know it was good when I fixed it. The valve wasn't
obviously torn, but the rubber seemed deteriorated in a spot by the base
of the valve where it was leaking. The problem turned up when I tried to
inflate it a bit before putting into the tire. BTW, I brought it home,
didn't leave it by the road as seems to be some people's custom. It was
in my under-seat bag for several months before I tried to use it today.
I would think that is a benign enough environment. I don't store the
bike near sources of ozone or nasty chemicals. Is there or has there
been a problem with defectively manufactured tubes? Any recommendations?

Mike

you're over-tightening the keeper thumbscrew - that always tears the
valve out of the tube. take it off and throw it away. it'll never
happen again. michelin tubes don't even have threaded valve stems.

Southern Comfort said:

Quoted message said:

Does any manufacturer make tubes with a sound attachment of a
Presta valve to the tube? I've been riding with them for about a
year and half now, and I've been through quite a number of tubes,
all of which have failed one way or another at the attachment of
the valve to the tube. The expense is hardly ruinous, but it is
annoying. I do know about holding head of the frame pump while
inflating to keep from jerking the valve around, so that doesn't
seem to be the reason for the problem. Had a flat today and was
lucky to have two spare tubes with me. The first spare leaked at
the junction of valve and tire. It was one I had patched before,
so I know it was good when I fixed it. The valve wasn't obviously
torn, but the rubber seemed deteriorated in a spot by the base of
the valve where it was leaking. The problem turned up when I tried
to inflate it a bit before putting into the tire. BTW, I brought
it home, didn't leave it by the road as seems to be some people's
custom. It was in my under-seat bag for several months before I
tried to use it today. I would think that is a benign enough
environment. I don't store the bike near sources of ozone or nasty
chemicals. Is there or has there been a problem with defectively
manufactured tubes? Any recommendations?

Quoted message said:

you're over-tightening the keeper thumbscrew - that always tears the
valve out of the tube. take it off and throw it away. it'll never
happen again. michelin tubes don't even have threaded valve stems.

Although this explanation has been offered on occasion, a simple test
will show that it is not so. Install the knurled nut with the fingers
when the tire is flat, inflate the tire fully and note that the nut is
no longer tight. Air pressure puts a greater load on the stem joint
than manual tightening of jam nut. It is there to assist using a
rigid head frame pump and prevents the stem from receding into a low
pressure tire.

Valve stem separation, a manufacturing flaw, was rampant a couple of
years ago and as often occurs, riders found blame with themselves
telling the stem nut scenario rather than question manufacture.

http://www.sheldonbrown.com/brandt/tube-failure.html#valve

Jobst Brandt

Mike McGuire said:

Does any manufacturer make tubes with a sound attachment of a presta
valve to the tube? I've been riding with them for about a year and half
now, and I've been through quite a number of tubes, all of which have
failed one way or another at the attachment of the valve to the tube.
The expense is hardly ruinous, but it is annoying. I do know about
holding head of the frame pump while inflating to keep from jerking the
valve around, so that doesn't seem to be the reason for the problem. Had
a flat today and was lucky to have two spare tubes with me. The first
spare leaked at the junction of valve and tire. It was one I had patched
before, so I know it was good when I fixed it. The valve wasn't
obviously torn, but the rubber seemed deteriorated in a spot by the base
of the valve where it was leaking. The problem turned up when I tried to
inflate it a bit before putting into the tire. BTW, I brought it home,
didn't leave it by the road as seems to be some people's custom. It was
in my under-seat bag for several months before I tried to use it today.
I would think that is a benign enough environment. I don't store the
bike near sources of ozone or nasty chemicals. Is there or has there
been a problem with defectively manufactured tubes? Any recommendations?

Mike

Very odd and unfortunate. Nothing dampens the spirit like multiple
flats. Just a thought --Have you by chance checked the rim valve hole
for burrs or sharp edges?
I am glad to hear you are not one of the [censored] that leave their old
tubes on the side of the road. It makes all of us look bad.

-Nate

Quoted message said:

Southern Comfort said:

Quoted message said:

Does any manufacturer make tubes with a sound attachment of a
Presta valve to the tube? I've been riding with them for about a
year and half now, and I've been through quite a number of tubes,
all of which have failed one way or another at the attachment of
the valve to the tube. The expense is hardly ruinous, but it is
annoying. I do know about holding head of the frame pump while
inflating to keep from jerking the valve around, so that doesn't
seem to be the reason for the problem. Had a flat today and was
lucky to have two spare tubes with me. The first spare leaked at
the junction of valve and tire. It was one I had patched before,
so I know it was good when I fixed it. The valve wasn't obviously
torn, but the rubber seemed deteriorated in a spot by the base of
the valve where it was leaking. The problem turned up when I tried
to inflate it a bit before putting into the tire. BTW, I brought
it home, didn't leave it by the road as seems to be some people's
custom. It was in my under-seat bag for several months before I
tried to use it today. I would think that is a benign enough
environment. I don't store the bike near sources of ozone or nasty
chemicals. Is there or has there been a problem with defectively
manufactured tubes? Any recommendations?

Quoted message said:

you're over-tightening the keeper thumbscrew - that always tears the
valve out of the tube. take it off and throw it away. it'll never
happen again. michelin tubes don't even have threaded valve stems.

Although this explanation has been offered on occasion, a simple test
will show that it is not so. Install the knurled nut with the fingers
when the tire is flat, inflate the tire fully and note that the nut is
no longer tight.

and what happens then is that most people see this, tighten the begeezus
out of it "to prevent that happening again", and so the stem gets pulled
from the tube. i've seen it happen countless times, particularly with
mtb's. you should ride with amateurs occasionally.

Quoted message said:

Air pressure puts a greater load on the stem joint
than manual tightening of jam nut. It is there to assist using a
rigid head frame pump and prevents the stem from receding into a low
pressure tire.

Valve stem separation, a manufacturing flaw, was rampant a couple of
years ago and as often occurs, riders found blame with themselves
telling the stem nut scenario rather than question manufacture.

http://www.sheldonbrown.com/brandt/tube-failure.html#valve

Jobst Brandt

and if you use a threadless michelin tube, you will never ever have a
valve stem pull out. and once you've figured that out and thrown away
the thumbscrew, no other tube will ever pull a valve stem out either.

Mike McGuire said:

Does any manufacturer make tubes with a sound attachment of a presta
valve to the tube? I've been riding with them for about a year and half
now, and I've been through quite a number of tubes, all of which have
failed one way or another at the attachment of the valve to the tube.
The expense is hardly ruinous, but it is annoying. I do know about
holding head of the frame pump while inflating to keep from jerking the
valve around, so that doesn't seem to be the reason for the problem. Had
a flat today and was lucky to have two spare tubes with me. The first
spare leaked at the junction of valve and tire. It was one I had patched
before, so I know it was good when I fixed it. The valve wasn't
obviously torn, but the rubber seemed deteriorated in a spot by the base
of the valve where it was leaking. The problem turned up when I tried to
inflate it a bit before putting into the tire. BTW, I brought it home,
didn't leave it by the road as seems to be some people's custom. It was
in my under-seat bag for several months before I tried to use it today.
I would think that is a benign enough environment. I don't store the
bike near sources of ozone or nasty chemicals. Is there or has there
been a problem with defectively manufactured tubes? Any recommendations?

Mike

Threadless presta valves are the way to go if your having problems. There is an adaptor from the bike shop for threaded prester valves, to inflate tyre a at the service station.A couple of $.
The odd tube iv found on the paths, usually only need a patch.

Southern Comfort said:

and if you use a threadless michelin tube, you will never ever have
a valve stem pull out. and once you've figured that out and thrown
away the thumbscrew, no other tube will ever pull a valve stem out
either.

That assumes the fault is not with the tube in the first place. I
can't demonstrate that anymore because the local shops have a high
enough merchandise turnover that those tubes are no longer available,
but the ones I had were not subjected to the scenario described.
Besides, how can fingertips such torque on such a tiny knurled nut?

I often wonder how these fables get started. Just the sudden surge of
stem failures during a specific time and then none, should have been a
tip-off that it was a material failure.

Having always carried a Presta stem for latex tubes in my patch kit
from tubular tire days, that stem came in handy when the first of my
vulcanized clincher valve stems began separating. I easily pulled it
out the rest of the way and with the mushroom on the end of the
replacement stem moistened, it popped into the hole nicely and the
securing hex nut made it air tight. Just the ease with which I pulled
out the separating stem made obvious that it was not well bonded from
the factory. In contrast the stem of a healthy butyl tube cannot be
pulled out by hand without tearing up the tube.

Jobst Brandt

Quoted message said:

Southern Comfort said:

and if you use a threadless michelin tube, you will never ever have
a valve stem pull out. and once you've figured that out and thrown
away the thumbscrew, no other tube will ever pull a valve stem out
either.

That assumes the fault is not with the tube in the first place. I
can't demonstrate that anymore because the local shops have a high
enough merchandise turnover that those tubes are no longer available,
but the ones I had were not subjected to the scenario described.
Besides, how can fingertips such torque on such a tiny knurled nut?

I often wonder how these fables get started. Just the sudden surge of
stem failures during a specific time and then none, should have been a
tip-off that it was a material failure.

the probability of it being pervasive across multiple tube manufacturers
is zero. i say again, ride with some amateur mtb riders and you'll find
this to be a common problem. mr. can't hear, won't hear.

Quoted message said:

Having always carried a Presta stem for latex tubes in my patch kit
from tubular tire days, that stem came in handy when the first of my
vulcanized clincher valve stems began separating. I easily pulled it
out the rest of the way and with the mushroom on the end of the
replacement stem moistened, it popped into the hole nicely and the
securing hex nut made it air tight. Just the ease with which I pulled
out the separating stem made obvious that it was not well bonded from
the factory. In contrast the stem of a healthy butyl tube cannot be
pulled out by hand without tearing up the tube.

Jobst Brandt

jim beam said:

Mike McGuire said:

Does any manufacturer make tubes with a sound attachment of a presta
valve to the tube? I've been riding with them for about a year and
half now, and I've been through quite a number of tubes, all of which
have failed one way or another at the attachment of the valve to the
tube. The expense is hardly ruinous, but it is annoying. I do know
about holding head of the frame pump while inflating to keep from
jerking the valve around, so that doesn't seem to be the reason for
the problem. Had a flat today and was lucky to have two spare tubes
with me. The first spare leaked at the junction of valve and tire. It
was one I had patched before, so I know it was good when I fixed it.
The valve wasn't obviously torn, but the rubber seemed deteriorated in
a spot by the base of the valve where it was leaking. The problem
turned up when I tried to inflate it a bit before putting into the
tire. BTW, I brought it home, didn't leave it by the road as seems to
be some people's custom. It was in my under-seat bag for several
months before I tried to use it today. I would think that is a benign
enough environment. I don't store the bike near sources of ozone or
nasty chemicals. Is there or has there been a problem with defectively
manufactured tubes? Any recommendations?

Mike

you're over-tightening the keeper thumbscrew - that always tears the
valve out of the tube. take it off and throw it away. it'll never
happen again. michelin tubes don't even have threaded valve stems.

Check that the hole in the rim where the valve passes through doesn't
have a sharp edge. Use some smooth sandpaper to round off the edges of
the drilled hole.

Marty

<snip>

Quoted message said:

I am glad to hear you are not one of the [censored] that leave their old
tubes on the side of the road. It makes all of us look bad.

-Nate

The same folks who crumple up used gel-tubes and other food wrappers
and litter. Very irritating. But I have found that if I comment on that
sort of behavior while on a ride, with a good-hearted joking tone, it
gets folks to clean up their act. At least when I am around! Incentive
for me to ride more!

Sometimes I stop and go back to pick up the offending litter and give
it back: "You dropped this while putting it back in your pocket."

Joseph

Mike McGuire said:

Does any manufacturer make tubes with a sound attachment of a presta
valve to the tube?

http://groups.google.com/groups?q=%22marty+wallace%22&hl=en

http://groups.google.com/groups?q=%22marty+wallace%22&start=0&scoring...

http://www.wjla.com/news/stories/1005/270663.html

http://groups.google.com/group/alt.true-crime/browse_thread/thread/2c...

http://groups.google.com/group/aus.bicycle/browse_thread/thread/346cf...

Marty who? said:

Check that the hole in the rim where the valve passes through
doesn't have a sharp edge. Use some smooth sandpaper to round off
the edges of the drilled hole.

Hold it! We don't know where the leak was. What kind of tube was
this and was the leak in the reinforced pad that supports the valve
stem or was it the valve stem separating from that pad? The edge of
the stem hole in the rim is as bogus a culprit as the knurled stem nut
pulling the stem out of the tube but both of these are often mentioned.

So lets get back to the source. Precisely where and what was leaking?

Jobst Brandt

Quoted message said:

Besides, how can fingertips such torque on such a tiny knurled nut?

5kN pullout force!

--
Phil, Squid-in-Training

Quoted message said:

So lets get back to the source. Precisely where and what was leaking?

It was in the original post, clearly stated:

"I've been through quite a number of tubes, all of which have failed one way
or another at the attachment of the valve to the tube."

and

"Had a flat today and was lucky to have two spare tubes with me. The first
spare leaked at the junction of valve and tire. It was one I had patched
before, so I know it was good when I fixed it. The valve wasn't obviously
torn, but the rubber seemed deteriorated in a spot by the base of the valve
where it was leaking."

Is that at all ambiguous?

--
Phil, Squid-in-Training

Mike McGuire said:

The first
spare leaked at the junction of valve and tire. It was one I had patched
before, so I know it was good when I fixed it.

Despite the claims of some people, it is entirely possible that the rim
is wearing a hole into the stem/tube junction. This happens when you
either have a particularly bad burr left on the valve hole or (more
likely) you have installed the tube with a slight misalignment of the
stem. If the edge of the hole looks a little sharp you can clean it up
with a file. The next time you remount a tire, be sure to check the
stem alignment after you have gotten the first tire bead on. When you
can see the stem on both sides of the rim through the open bead of the
tire, shift the tire and tube on the wheel to get things just right.

Quoted message said:

It was
in my under-seat bag for several months before I tried to use it today.
I would think that is a benign enough environment. I don't store the
bike near sources of ozone or nasty chemicals.

You can wear holes in a spare tire if it finds anything to rub against
in your seat bag. This is what happened to your patched tube since you
would have found any pre-existing hole before you patched it and put it
into your bag. I keep my spare in a zip-lock bag lined with duct tape
(invert, apply tape, revert). This keeps it safe from any other tools.
I don't know if it helps, but I usually roll up the spare with the
valve in the middle of the coil as well.

Phil Lee said:

Quoted message said:

So lets get back to the source. Precisely where and what was leaking?

Quoted message said:

It was in the original post, clearly stated:

Quoted message said:

"I've been through quite a number of tubes, all of which have failed
one way or another at the attachment of the valve to the tube."

Yes? So where was the leak? was it in the rubber or was the leak
where the stem was separating from the rubber?

Quoted message said:

and

Quoted message said:

"Had a flat today and was lucky to have two spare tubes with me. The first
spare leaked at the junction of valve and tire. It was one I had patched
before, so I know it was good when I fixed it. The valve wasn't obviously
torn, but the rubber seemed deteriorated in a spot by the base of the valve
where it was leaking."

Quoted message said:

Is that at all ambiguous?

Highly! If you can patch it, it wasn't stem separation nor was it
cause by the stem hole in the rim either because that would have been
within a couple of mm of the stem, a difficult hole to patch.
Besides, the tube rubber is so thick at that place that rim abrasion
would not cause a leak. That is one reason why tubes are reinforced
at that place. Tubulars with thin latex tubes had a chafing strip of
tough rubberized cloth around the stem for that reason.

So where and what was the leak, so we can assess the cause and give
some useful advice instead of vaguely hypothesizing about solutions?

Jobst Brandt

Mike: (clip) The first spare leaked at the junction of valve and tire. It
was one I had patched before, so I know it was good when I fixed it.
^^^^^^^^^^^^^^^
Jobst: (clip) If you can patch it, it wasn't stem separation nor was it
cause by the stem hole in the rim either because that would have been within
a couple of mm of the stem, a difficult hole to patch.
^^^^^^^^^^^^^^^^
Jobst, I think he meant that he had repaired an ordinary leak on that tube,
using an ordinary patch, and following that, it developed at leak at the
foot of the stem. What I think he intended to convey was that the stem was
holding air at the time he took it out of service, but started to leak when
he reused it.

Mike McGuire said:

Does any manufacturer make tubes with a sound attachment of a presta
valve to the tube? I've been riding with them for about a year and half
now, and I've been through quite a number of tubes, all of which have
failed one way or another at the attachment of the valve to the tube.
The expense is hardly ruinous, but it is annoying. I do know about
holding head of the frame pump while inflating to keep from jerking the
valve around, so that doesn't seem to be the reason for the problem. Had
a flat today and was lucky to have two spare tubes with me. The first
spare leaked at the junction of valve and tire. It was one I had patched
before, so I know it was good when I fixed it. The valve wasn't
obviously torn, but the rubber seemed deteriorated in a spot by the base
of the valve where it was leaking. The problem turned up when I tried to
inflate it a bit before putting into the tire. BTW, I brought it home,
didn't leave it by the road as seems to be some people's custom. It was
in my under-seat bag for several months before I tried to use it today.
I would think that is a benign enough environment. I don't store the
bike near sources of ozone or nasty chemicals. Is there or has there
been a problem with defectively manufactured tubes? Any recommendations?

I had a bunch (~6) of tubes fail with a stem/tube separation. I think
most of them were Specialized brand. The last one failed a few days ago,
the tube had many patches on it, and I don't get flats very often, so
the tube was probably 3-4 years old.

Many of these failures show up as a slow leak that only is detectable
off the bike by tipping the stem -- sometimes under water.

As for the nut theory -- I never use the nuts. As for the sharp edges
theory -- mine aren't, at least there's no sign of cutting, it's simply
that the stem and tube seem to be losing attachment.

Quoted message said:

BTW, I brought it home,
didn't leave it by the road as seems to be some people's custom.

Never seen this -- I can't imagine why anyone would do it.

Phil said:

Quoted message said:

I would have tried to peel off the entire stem pad in that event
just to see how bad that joint was. I haven't had the opportunity
to do that, but I have had stems that could be easily separated
from the rubber.

Quoted message said:

When you say this, are you saying that the valve, without any of the
thick rubber "flange" attached, could be removed cleanly with any
jagged ripping? IME, I have had tubes and customer's tubes of
various brands do this.

I'm saying that the stem pad (which IS thicker) might peel off if that
is where separation occurred.

Quoted message said:

The bad part is that the leak is not immediately located because at low
pressures when the tube is outside of the tire, the broken valve/tube
junction is tight enough not to let air through, but when it is inflated
inside a tire, the air just streams out. I try to check tubes by lightly
wiggling the valve to check for separation.

Quoted message said:

I've never seen the thick rubber around the valve separate from the thin
rubber, only the valve stem itself from the thick rubber.

That has been my experience as well. As I said, I have inserted a
Presta stem from a tubular tire in that hole and used it for many
miles.

Jobst Brandt

Quoted message said:

It was this kind that were common for a short time and were
immediately attributed to the stem nut because bicyclists like to
believe equipment is faultless and the user the culprit.

For good reason: in almost any discipline, user error is the cause of most
of the problems. IT is particularly egregious, of course, but the same
applies most places.

Jasper