Specialized tubes -- more stem failures
Matt O'Toole
I went on a MTB ride late this afternoon. Though light was fading we
decided to do one more loop. On the way down I felt my rear tire go flat.
I got out my spare tube and started pumping with my friend's pump (I had
forgotten mine). On removing the pump, I pulled the valve stem right out
of the tube! Because I had patches I decided to patch the first tube.
But on pumping it I discovered the leak was at the base of the valve stem,
unpatchable. It was a slow leak though, so I decided to pump it and ride
on it as far as I could. Well it lasted most of the way, but by this time
it was dark. Thankfully someone had a light.
Guess what brand these tubes were?
Surprise -- Specialized!
Unfortunately I needed a couple of tubes last year while on vacation, so
against my better judgment I bought these because they were the only ones
the bike shop had. Thus I was burned again, by the stem failure problem
endemic to this brand for over a decade.
So do not buy Specialized tubes. If you're a bike shop owner, please do
us all a favor and stock another brand instead. Cheng Shin, for example,
or Michelin.
Matt O.
bfd
tubes. I had this same problems with tubes sold as Clement, Vittoria
and lately, Performance. Further, Specialized doesn't make their own
tubes, they buy it from the same factory as the others. I believe all
of the tubes are made in the same factory in Thailand.
I'm thinking the mfrs are specifying less rubber around the valve stem
to "reduce" the weight of the tube and/or cut cost. It may only be like
a few pennies or even a nickel per tube, but add it up by the thousands
and it can be a substantial savings.
jobst....@stanfordalumni.org
> OK, this is really annoying.
> I went on a MTB ride late this afternoon. Though light was fading we
> decided to do one more loop. On the way down I felt my rear tire go
> flat. I got out my spare tube and started pumping with my friend's
> pump (I had forgotten mine). On removing the pump, I pulled the
> valve stem right out of the tube! Because I had patches I decided
> to patch the first tube. But on pumping it I discovered the leak
> was at the base of the valve stem, unpatchable. It was a slow leak
> though, so I decided to pump it and ride on it as far as I could.
> Well it lasted most of the way, but by this time it was dark.
> Thankfully someone had a light.
Well they are patchable if you carry a Presta tubular tire stem in
your patch kit:
http://www.yellowjersey.org/NUVALVE.JPG
Remove the rest of the failed stem as cleanly as possible, wet the
tubular stem mushroom and pop it in the stem hole. You'll need some
sort of wrench to tighten the hex clamp nut and you're done.
> Guess what brand these tubes were?
> Surprise -- Specialized!
Of course Specialized is responsible for the quality of products sold
under their name but as we saw with road bicycle tubes, the stem
separation was present in most brands at the time, showing that they
are packaged under different labels by the same manufacturer.
Fortunately that period is past and your tube may be a left over from
that era. You may have noticed the self flagellation of some
contributors here who put the blame on the user saying that they
pumped incorrectly or crewed the stem jam nut too tightly. Neither of
these can tear the stem out inadvertently. It takes substantial
effort.
> Unfortunately I needed a couple of tubes last year while on
> vacation, so against my better judgment I bought these because they
> were the only ones the bike shop had. Thus I was burned again, by
> the stem failure problem endemic to this brand for over a decade.
That must have been old stock and from the time when the manufacturer
of all these tubes had a process failure that caused a weak bond.
> So do not buy Specialized tubes. If you're a bike shop owner,
> please do us all a favor and stock another brand instead. Cheng
> Shin, for example, or Michelin.
I think your advice is misplaced. The whole stem separation problem
has gone away with more recently supplied tubes.
Jobst Brandt
Mike Jacoubowsky
> that era. You may have noticed the self flagellation of some
> contributors here who put the blame on the user saying that they
> pumped incorrectly or crewed the stem jam nut too tightly. Neither of
> these can tear the stem out inadvertently. It takes substantial
> effort.
So it's entirely coincidence that those new to the activity tear out far
more valves from tubes than those who have been around for awhile?
--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA
<jobst....@stanfordalumni.org> wrote in message
news:454653a0$0$34544$742e...@news.sonic.net...
G.T.
"Mike Jacoubowsky" <Mi...@ChainReaction.com> wrote in message
news:QRv1h.1688$wX....@newssvr12.news.prodigy.com...
> > Fortunately that period is past and your tube may be a left over from
> > that era. You may have noticed the self flagellation of some
> > contributors here who put the blame on the user saying that they
> > pumped incorrectly or crewed the stem jam nut too tightly. Neither of
> > these can tear the stem out inadvertently. It takes substantial
> > effort.
>
> So it's entirely coincidence that those new to the activity tear out far
> more valves from tubes than those who have been around for awhile?
>
So it's the customer's fault now? So Matt's "new to the activity"? My
riding partners with an aggregate of 120 years of using presta valves are
"new to the activity"?
What a fucked up attitude.
Greg
Mike Jacoubowsky
>> more valves from tubes than those who have been around for awhile?
>>
>
> So it's the customer's fault now? So Matt's "new to the activity"? My
> riding partners with an aggregate of 120 years of using presta valves are
> "new to the activity"?
That's not what I said. I was pointing out that torn valve stems are *far*
more common with people newer to the sport than those who have been around
for a while. That doesn't mean that there aren't bad tubes out there; sorry
if I implied that. I was responding to what appeared to be an absolute; that
the cyclist is never at fault for a torn valve. The truth is someplace
in-between. (And yes, I've seen tubes damaged by people over-tightening
valve nuts).
--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA
"G.T." <getn...@dslextreme.com> wrote in message
news:12kd5og...@corp.supernews.com...
Michael Warner
> That's not what I said. I was pointing out that torn valve stems are *far*
> more common with people newer to the sport than those who have been around
> for a while. That doesn't mean that there aren't bad tubes out there; sorry
> if I implied that. I was responding to what appeared to be an absolute; that
> the cyclist is never at fault for a torn valve. The truth is someplace
> in-between. (And yes, I've seen tubes damaged by people over-tightening
> valve nuts).
Does using those nuts correctly extend tube life, even if you're not rough
on the valve stem? I haven't bothered putting one on for ages.
--
Home page: http://members.westnet.com.au/mvw
G.T.
"Michael Warner" <s...@homepage.com> wrote in message
news:1k9nm9sofrwv1$.1jqj6ib3hjg03$.dlg@40tude.net...
Yeah, I haven't put one on in over 20 years. With low pressure mtn bike
tubes I'd rather have the stem end up crooked rather than the stem being
tugged on with the nut tightened down.
Greg
Matt O'Toole
> Well they are patchable if you carry a Presta tubular tire stem in your
> patch kit:
>
> http://www.yellowjersey.org/NUVALVE.JPG
>
> Remove the rest of the failed stem as cleanly as possible, wet the
> tubular stem mushroom and pop it in the stem hole. You'll need some
> sort of wrench to tighten the hex clamp nut and you're done.
Why mess with this if it can be avoided by using tubes that don't
have stem failures?
> Of course Specialized is responsible for the quality of products sold
> under their name but as we saw with road bicycle tubes, the stem
> separation was present in most brands at the time, showing that they are
> packaged under different labels by the same manufacturer.
Specialized is the only brand I've had trouble with, but then it's
the only brand that a lot of shops sell. The failure rate for Specialized
tubes has been near 100% for me.
I've never had trouble with a Michelin tube.
> Fortunately that period is past and your tube may be a left over from
> that era.
and...
> That must have been old stock and from the time when the manufacturer of
> all these tubes had a process failure that caused a weak bond.
This is possible but it's not my job to make sure a shop's inventory is up
to date with non-defective merchandise.
Matt O.
jim beam
> On Tue, 31 Oct 2006 03:19:06 GMT, Mike Jacoubowsky wrote:
>
>> That's not what I said. I was pointing out that torn valve stems are *far*
>> more common with people newer to the sport than those who have been around
>> for a while. That doesn't mean that there aren't bad tubes out there; sorry
>> if I implied that. I was responding to what appeared to be an absolute; that
>> the cyclist is never at fault for a torn valve. The truth is someplace
>> in-between. (And yes, I've seen tubes damaged by people over-tightening
>> valve nuts).
>
> Does using those nuts correctly extend tube life, even if you're not rough
> on the valve stem?
doubt it. other than aiding initial inflation, they serve no purpose
whatsoever.
> I haven't bothered putting one on for ages.
valve nuts are best utilized in the practice of one's throw - the
further away the better. michelin don't even have a threaded stem -
they know what they're doing.
jobst....@stanfordalumni.org
>> That's not what I said. I was pointing out that torn valve stems
>> are *far* more common with people newer to the sport than those who
>> have been around for a while. That doesn't mean that there aren't
>> bad tubes out there; sorry if I implied that. I was responding to
>> what appeared to be an absolute; that the cyclist is never at fault
>> for a torn valve. The truth is someplace in-between. (And yes, I've
>> seen tubes damaged by people over-tightening valve nuts).
> Does using those nuts correctly extend tube life, even if you're not
> rough on the valve stem? I haven't bothered putting one on for ages.
The nut helps keep the stem from submerging into the rim when a
push-on pump head is used, one like the Campagnolo pump head. This is
more a problem with an uninflated or low pressure tube.
The claim that screwing the knurled nut down snugly by hand is what
separates valve stems doesn't hold up when tested. After manually
tightening the nut and inflating the tire to 100psi, the nut will
again be loose and free to turn, inflation pressure exerting more
force than thumb and forefinger can generate with the knurled nut.
Jobst Brandt
jobst....@stanfordalumni.org
>> Well they are patchable if you carry a Presta tubular tire stem in
>> your patch kit:
http://www.sheldonbrown.com/brandt/tube-failure.html#valve
>> Remove the rest of the failed stem as cleanly as possible, wet the
>> tubular stem mushroom and pop it in the stem hole. You'll need
>> some sort of wrench to tighten the hex clamp nut and you're done.
> Why mess with this if it can be avoided by using tubes that don't
> have stem failures?
How do you know the tube you are riding has a failsafe stem.
Besides, why throw and otherwise good tube away if all you need to do
is insert a stem that you can get from any bicycle shop that has
tubular users.
>> Of course Specialized is responsible for the quality of products
>> sold under their name but as we saw with road bicycle tubes, the
>> stem separation was present in most brands at the time, showing
>> that they are packaged under different labels by the same
>> manufacturer.
> Specialized is the only brand I've had trouble with, but then it's
> the only brand that a lot of shops sell. The failure rate for
> Specialized tubes has been near 100% for me.
Well, I have had all sorts of them a year or so ago. If you search,
you can find that this was discussed at that time and elicited a
firestorm of flames concerning the knurled nut and poor pumping skill.
> I've never had trouble with a Michelin tube.
So use them but don't say that only Specialized has stem separations.
>> Fortunately that period is past and your tube may be a left over
>> from that era.
> and...
>> That must have been old stock and from the time when the
>> manufacturer of all these tubes had a process failure that caused a
>> weak bond.
> This is possible but it's not my job to make sure a shop's inventory
> is up to date with non-defective merchandise.
Or your own inventory of tubes on your shelf or in your reserve pocket.
Jobst Brandt
Nate Knutson
Yeah, but then people tend to tighten them down again. Then what seems
to happen is that the area around the base of the valve gets pulled
around and stressed when the bike is ridden with low tire pressure -
which is usually a mistake on the rider's part, unless their doing a
type of riding where it makes sense to switch to a much lower pressure
and are unaware of the interactions caused by the presta nut. That's my
hypothesis at least.
Michael Warner
> The nut helps keep the stem from submerging into the rim when a
> push-on pump head is used, one like the Campagnolo pump head.
No worries then. I don't use that Italian rubbish :-)
jobst....@stanfordalumni.org
> the Presta nut.
I can only imagine that those who believe in the tiny knurled nut
causing stem separations don't manually pump tires with a frame fit
pump or they wouldn't be so sure the nut has no function. Besides, it
has been around for about 40 years before stem separations showed up.
That was back in the days when people pumped their tires with a Silca
Impero pump.
http://www.yellowjersey.org/silca.html
> That's my hypothesis at least.
Good you add that.
Jobst Brandt
* * Chas
<jobst....@stanfordalumni.org> wrote in message
news:4546eb6f$0$34531$742e...@news.sonic.net...
About 30 years ago when Michelin first started making presta tubes with
the stem vulcanized into them we saw quite a few failures. I think that
they were developed for Michelin's Elan tires which were some of the
first high pressure small cross section clincher tires and were designed
to replace sewups. Some double walled rims had a larger valve stem hole
inside the rim to allow clearance for valve stems with lock nuts.
The Michelin tubes without lock nuts on the stems tended to herniate
into the larger hole and eventually fail. Our quick and dirty solution
was to cut 1" squares from old tubes and punch a hole in the middle with
a paper punch. We slipped these over the valve stem as a reinforcement
before installing the tube. They drastically cut down on failures around
the stems on these tubes.
One trick for pumping up with presta valves is to spit on the rubber
grommet in the Silca hose end or Campy/Silca pump tip. It makes for an
easier fit over the stem (this isn't necessary with some of the newer
pumps with clamp on tips). The other trick is rotate the wheel so that
the valve is at the top before pumping. To remove the pump hold it near
the tip end with one hand and tap it downward with the open palm of the
other hand. A quick forceful downward tap works better than trying to
work it off.
I wonder how many people having problems with stem failure are running
light weight tubes? I run standard Michelin AirStop tubes in most of my
clincher wheels and have never had any problems with them. Also, I have
2 sets of wheels with Specialized presta tubes that I been using since
the early 1990's and they still seem OK.
Chas.
diann...@yahoo.com
> Some double walled rims had a larger valve stem hole
> inside the rim to allow clearance for valve stems with lock nuts.
Most Rolf and Bontrager rim's I've seen have larger holes inside, too.
I haven't seen many tubes with nutted valves, so I'm wondering if maybe
there's another reason for the larger rim hole?
Tim McNamara
the rubber are sold under the "Specialized" brand. Haven't had any
further problems (in the same wheels) since I stopped buying that brand.
Mike Jacoubowsky
> separates valve stems doesn't hold up when tested. After manually
> tightening the nut and inflating the tire to 100psi, the nut will
> again be loose and free to turn, inflation pressure exerting more
> force than thumb and forefinger can generate with the knurled nut.
EXACTLY! And therein lies the problem, because the now-loose nut is buzzing,
so you crank it down to get rid of the noise. The problem isn't caused by
the initial tightening; sorry if that's how it came across. They may
actually be useful initially (during pumping), and I suggest to customers
they can use them at that time, and then remove them so they don't buzz.
--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA
<jobst....@stanfordalumni.org> wrote in message
news:4546e9e5$0$34531$742e...@news.sonic.net...
jobst....@stanfordalumni.org
>> The claim that screwing the knurled nut down snugly by hand is what
>> separates valve stems doesn't hold up when tested. After manually
>> tightening the nut and inflating the tire to 100psi, the nut will
>> again be loose and free to turn, inflation pressure exerting more
>> force than thumb and forefinger can generate with the knurled nut.
> EXACTLY! And therein lies the problem, because the now-loose nut is
> buzzing, so you crank it down to get rid of the noise. The problem
> isn't caused by the initial tightening; sorry if that's how it came
> across. They may actually be useful initially (during pumping), and
> I suggest to customers they can use them at that time, and then
> remove them so they don't buzz.
What? Buzzing? In all the years of riding with stem nuts on Presta
valves, I haven't heard a sound from them, even at brisk speed in the
silence of a tailwind. Besides, the next time I pump that tire on the
road, I want the nut to be in place on the stem of the replacement
tube. There is no reason to throw the nut away other than tossing it
over the appropriate shoulder to prevent attack by vampires.
That is what the whole stem nut story is about, myth and lore.
Jobst Brandt
Mike Jacoubowsky
>> buzzing, so you crank it down to get rid of the noise. The problem
>> isn't caused by the initial tightening; sorry if that's how it came
>> across. They may actually be useful initially (during pumping), and
>> I suggest to customers they can use them at that time, and then
>> remove them so they don't buzz.
>
> What? Buzzing? In all the years of riding with stem nuts on Presta
> valves, I haven't heard a sound from them, even at brisk speed in the
> silence of a tailwind. Besides, the next time I pump that tire on the
> road, I want the nut to be in place on the stem of the replacement
> tube. There is no reason to throw the nut away other than tossing it
> over the appropriate shoulder to prevent attack by vampires.
>
> That is what the whole stem nut story is about, myth and lore.
Oh my. Myth & lore? Doesn't hold water in this case. This isn't hard to
test; you can demonstrate it very easily. Just put a valve nut onto a stem
and bounce it lightly on the ground. If your ears can't hear it, I'd be
quite surprised. And you'd obviously be *very* surprised at the number of
customers we have who bring in their bikes for mystery noises which turn out
to be one... valve nuts buzzing.
Anyone doubting this should try the experiment themselves.
--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA
<jobst....@stanfordalumni.org> wrote in message
news:4547d97d$0$34503$742e...@news.sonic.net...
G.T.
"Mike Jacoubowsky" <Mi...@ChainReaction.com> wrote in message
> >> EXACTLY! And therein lies the problem, because the now-loose nut is
> >> buzzing, so you crank it down to get rid of the noise. The problem
> >> isn't caused by the initial tightening; sorry if that's how it came
> >> across. They may actually be useful initially (during pumping), and
> >> I suggest to customers they can use them at that time, and then
> >> remove them so they don't buzz.
> >
> > What? Buzzing? In all the years of riding with stem nuts on Presta
> > valves, I haven't heard a sound from them, even at brisk speed in the
> > silence of a tailwind. Besides, the next time I pump that tire on the
> > road, I want the nut to be in place on the stem of the replacement
> > tube. There is no reason to throw the nut away other than tossing it
> > over the appropriate shoulder to prevent attack by vampires.
> >
> > That is what the whole stem nut story is about, myth and lore.
>
> Oh my. Myth & lore? Doesn't hold water in this case. This isn't hard to
> test; you can demonstrate it very easily. Just put a valve nut onto a stem
> and bounce it lightly on the ground.
I just did. Didn't hear a thing.
Greg
jobst....@stanfordalumni.org
>>> EXACTLY! And therein lies the problem, because the now-loose nut
>>> is buzzing, so you crank it down to get rid of the noise. The
>>> problem isn't caused by the initial tightening; sorry if that's
>>> how it came across. They may actually be useful initially (during
>>> pumping), and I suggest to customers they can use them at that
>>> time, and then remove them so they don't buzz.
>> What? Buzzing? In all the years of riding with stem nuts on
>> Presta valves, I haven't heard a sound from them, even at brisk
>> speed in the silence of a tailwind. Besides, the next time I pump
>> that tire on the road, I want the nut to be in place on the stem of
>> the replacement tube. There is no reason to throw the nut away
>> other than tossing it over the appropriate shoulder to prevent
>> attack by vampires.
>> That is what the whole stem nut story is about, myth and lore.
> Oh my. Myth & lore? Doesn't hold water in this case. This isn't
> hard to test; you can demonstrate it very easily. Just put a valve
> nut onto a stem and bounce it lightly on the ground. If your ears
> can't hear it, I'd be quite surprised. And you'd obviously be
> *very* surprised at the number of customers we have who bring in
> their bikes for mystery noises which turn out to be one... valve
> nuts buzzing.
Oh! I'm sorry. I didn't know you were talking about basketball.
> Anyone doubting this should try the experiment themselves.
...and you can hear a buzzing sound from that nut while riding? I
don't believe it. The nut is held radially in its threads snugly by
centrifugal force even if it isn't tightened against the rim.
Jobst Brandt
carl...@comcast.net
Dear Mike,
In between greedy children begging for candy, I tried your experiment,
wondering if you were insane.
Nope.
With the valve stem horizontal and the valve stem nut loose, my rear
wheel gave a small but noticeable buzz or rattle when bounced off a
concrete floor about three inches.
When I tightened the valve stem nut, the noise vanished.
It might make less or only intermittent noise when the wheel is
whirling around and just hitting bumps, but there's no question that
the noise is there.
And hard-to-find little noises are the hobgoblins of many minds on
RBT, both large and small.
Now to look into why the tire lost 20 psi in a few days. Surely it
can't be goathead punctures mostly sealed by Slime.
Cheers,
Carl Fogel
Robin Hubert
While I agree that there is no problem caused by valve nuts, I don't
think they are necessary or a great advantage for on-road tire pumping.
It takes no effort to apply pressure through the flat or low pressure
tire with one hand while pressing the head of the pump onto the valve
with the other. One less bit. No problem. If your pump head won't
stay on I'd get another version.
Robin Hubert
KERRY MONTGOMERY
"Robin Hubert" <cv2...@hotmail.com> wrote in message
news:5QV1h.598$0r....@newsread1.news.pas.earthlink.net...
> jobst....@stanfordalumni.org wrote:
>> Mike Jacoubowsky writes:
>>
>>>>> EXACTLY! And therein lies the problem, because the now-loose nut
>>>>> is buzzing, so you crank it down to get rid of the noise.
This can cause a problem; after a flat on the road, the nut may now be very
tight, and quite difficult to remove.
Kerry
Johnny Sunset aka Tom Sherman
>
> What? Buzzing? In all the years of riding with stem nuts on Presta
> valves, I haven't heard a sound from them, even at brisk speed in the
> silence of a tailwind. Besides, the next time I pump that tire on the
> road, I want the nut to be in place on the stem of the replacement
> tube.
Removing the nuts will increase your climbing speed by
0.0000000014597834%!
> There is no reason to throw the nut away other than tossing it
> over the appropriate shoulder to prevent attack by vampires.
Forget about vampires - the real danger while riding is RECUMBENT
BICYCLE EVANGELISTS! ;)
> That is what the whole stem nut story is about, myth and lore.
This whole discussion is just plain nuts!
--
Tom Sherman - Here, not there.
I am supporting cannibalism by eating more nuts.
carl...@comcast.net
Drat! Goathead puncture, mostly sealed by Slime.
CF
Matt O'Toole
> How do you know the tube you are riding has a failsafe stem.
Experience. I've not had failures with certain brands, nor has anyone I
know.
> Besides,
> why throw and otherwise good tube away if all you need to do is insert a
> stem that you can get from any bicycle shop that has tubular users.
Wouldn't it be great if most shops actually stocked parts like this? If
they did, they'd probably charge as much as for a whole new tube anyway.
>> This is possible but it's not my job to make sure a shop's inventory is
>> up to date with non-defective merchandise.
> Or your own inventory of tubes on your shelf or in your reserve pocket.
Agreed. As of yesterday it's been changed. As I already said, I relied
on the known-troublesome ones against my better judgment.
This is a good point about being responsible for one's equipment though.
Matt O.
Mike Jacoubowsky
>> hard to test; you can demonstrate it very easily. Just put a valve
>> nut onto a stem and bounce it lightly on the ground. If your ears
>> can't hear it, I'd be quite surprised. And you'd obviously be
>> *very* surprised at the number of customers we have who bring in
>> their bikes for mystery noises which turn out to be one... valve
>> nuts buzzing.
>
> Oh! I'm sorry. I didn't know you were talking about basketball.
You've lost me on that one.
>> Anyone doubting this should try the experiment themselves.
>
> ...and you can hear a buzzing sound from that nut while riding? I
> don't believe it. The nut is held radially in its threads snugly by
> centrifugal force even if it isn't tightened against the rim.
Yes, you can hear it while riding. No kidding. You can argue centrifugal
force, and I can argue what I can observe, both using the bounce test and by
riding it. I'll go for observed phenomenon over theories that centrifugal
force is strong enough to force the nut firmly enough against the threads to
immobilize it.
--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com
<jobst....@stanfordalumni.org> wrote in message
news:45480686$0$34504$742e...@news.sonic.net...
* * Chas
<jobst....@stanfordalumni.org> wrote in message
news:4547d97d$0$34503$742e...@news.sonic.net...
I agree. In 35 years of using presta valve tubes and sewups I've never
had a problem with valve stem nuts.
Chas.
Michael Press
<pan.2006.11.01...@letterboxes.org>,
Matt O'Toole <matto...@letterboxes.org> wrote:
> On Tue, 31 Oct 2006 06:21:35 +0000, jobst.brandt wrote:
> > Besides,
> > why throw and otherwise good tube away if all you need to do is insert a
> > stem that you can get from any bicycle shop that has tubular users.
>
> Wouldn't it be great if most shops actually stocked parts like this? If
> they did, they'd probably charge as much as for a whole new tube anyway.
The stem can be used on the next tube, after the
current tube has a blow-out.
--
Michael Press
jobst....@stanfordalumni.org
>> How do you know the tube you are riding has a failsafe stem.
> Experience. I've not had failures with certain brands, nor has
> anyone I know.
>> Besides, why throw and otherwise good tube away if all you need to
>> do is insert a stem that you can get from any bicycle shop that has
>> tubular users.
> Wouldn't it be great if most shops actually stocked parts like this?
> If they did, they'd probably charge as much as for a whole new tube
> anyway.
I said, a bicycle shop that deals in tubulars. Get one with a latex
tube out of the junk pile and extract the stem. You don BUY them! I
have a stack of them left over from the Clement days.
>>> This is possible but it's not my job to make sure a shop's
>>> inventory is up to date with non-defective merchandise.
>> Or your own inventory of tubes on your shelf or in your reserve
>> pocket.
> Agreed. As of yesterday it's been changed. As I already said, I
> relied on the known-troublesome ones against my better judgment.
> This is a good point about being responsible for one's equipment
> though.
It doesn't hurt to carry a spare stem unless you are a weight weenie.
Jobst Brandt
carl...@comcast.net
[snip]
>I said, a bicycle shop that deals in tubulars. Get one with a latex
>tube out of the junk pile and extract the stem. You don BUY them! I
>have a stack of them left over from the Clement days.
[snip]
Dear Jobst,
Another good example of local variation.
Where you live near San Francisco, a shop that deals in tubulars and
has a junk pile with tubulars containing latex tubes is probably easy
to find.
Maybe not as easy to find as goatheads where I live or as common as
flints in southern England, but still pretty easy.
But my curiosity is piqued. I'll call around Pueblo tomorrow and see
if Great Divide, Bob's Bicycles, or Vance's Bike World even sells
tubulars.
I vaguely suspect that my former neighbors got their tubulars out of
town and quickly gave up riding here, preferring bicycling trips to
Italy, but maybe one of the three bike shops here will surprise me.
Reminds me of people who ask me if I recommend Apple computers. I ask
them where they plan to buy Apples around here. Pueblo, a steel mill
and farming town, has a population of only around 100,000, so tubulars
and Apples are a bit scarce. Go 120 miles north to Boulder, a
university town, and Peter Chisholm happily uses both.
Cheers,
Carl Fogel
Luns Tee
>>I said, a bicycle shop that deals in tubulars. Get one with a latex
>>tube out of the junk pile and extract the stem. You don BUY them! I
>>have a stack of them left over from the Clement days.
>Where you live near San Francisco, a shop that deals in tubulars and
>has a junk pile with tubulars containing latex tubes is probably easy
>to find.
I haven't looked hard outside of Berkeley, but have yet to find
any. None of the shops I've asked so far keep carcasses from the
Clement days around, except for the odd one or two that are mounted on
their window display museum pieces.
From talking to people in the shops though, the impression I
get is that modern latex tubes don't use the removable stems of yore.
The boxed latex tubes that I've examined have the same butyl
foot on the stem as butyl tubes; they're able to bond the butyl foot to
latex nowadays. I have to believe that current-day tubulars use these
same tubes, so even finding a fresh supply of junk tubulars doesn't help
much. I wouldn't be at all surprised if some of these butyl feet tear
off their stems just as they've done on butyl tubes.
-Luns
carl...@comcast.net
Dear Luns,
You monster!
Now you've spoiled my innocent dream of a place somewhere over the
rainbow where skies are blue and friendly bike shops have garbage cans
full of juicy parts that I can scavenge for free.
Next you'll tell me that modern buggy whips are made of braided nylon,
not leather.
On a more realistic note, it's possible that Jobst scavenged the nifty
part a long time ago, but has never needed to replace it and hasn't
kept up with the times.
The possibility occurs to me because there are a lot of odd little
parts and tools lurking around Fogel Labs that fit that description,
things that seemed quite sensible and clever and useful and yet
somehow have never needed replacing since they were obtained.
Maybe I won't call the three bike shops in Pueblo tomorrow. But I'm
still hoping that Jobst will name a Stanford bike shop that has a box
of old tubies with the replacement stem that he carries.
Cheers,
Carl Fogel
Jasper Janssen
wrote:
>valve nuts are best utilized in the practice of one's throw - the
>further away the better. michelin don't even have a threaded stem -
>they know what they're doing.
Hey, Jim.. Advocating polluting the environment of your rides with presta
stem nuts is not cool.
Jasper
Jasper Janssen
<sunset...@yahoo.com> wrote:
>Removing the nuts will increase your climbing speed by
>0.0000000014597834%!
Admittedly, it's the cheapest weight-loss off your bicycle you can get. I
wonder if the difference in weight for, say, a rear derailer between
Ultegra and DA is that much more than a few stem nuts. Let alone things
like extrasuperlight jockey wheels.
Jasper
jim beam
did i say i'm not aiming for a trash can? besides, let's get some
perspective here - the environmental impact of a little inorganic brass
is a good deal less than the organics in shed tire rubber, shed chain
lube, shed brake pad and, heaven forbid, pissed pharmaceutical
by-products that originated in your doctor's office or your farmer's
veterinarian bag/pest control regimen.
* * Chas
"Jasper Janssen" <jas...@jjanssen.org> wrote in message
news:3iqjk259b62qdmnu1...@4ax.com...
How about "carbon" (reinforced carbon fiber composite) nuts? They would
save a gram or two!
Chas.
Jasper Janssen
>Drat! Goathead puncture, mostly sealed by Slime.
So you were right the first time: it wasn't puncture*s*.
Jasper
Jasper Janssen
<Mi...@ChainReaction.com> wrote:
> valve nuts buzzing.
Did a new all-valve-high-end-audio-amplifier get released? That always
sets the valve[1] nuts buzzing in the audiophool community.
Jasper
[1] en.US: Vacuum tubes.
Dane Buson
> On Tue, 31 Oct 2006 23:43:52 GMT, "Mike Jacoubowsky"
> <Mi...@ChainReaction.com> wrote:
>
>> valve nuts buzzing.
>
> Did a new all-valve-high-end-audio-amplifier get released? That always
> sets the valve[1] nuts buzzing in the audiophool community.
I'm personally waiting for my Altmann Acoustic Panel to arrive in the
mail. It's not just wood, Hell no, this is *audiophile* wood.
http://www.ilikejam.dsl.pipex.com/audiophile.htm
[1] Legacy footnote: not supported.
--
Dane Buson - sig...@unixbigots.org
"It's just one big merry-go-round." --Hustler publisher Larry Flynt,
on the frequency of affairs between congressmen and interns
Michael Press
<4faq14-...@curare.zuvembi.homelinux.org>,
Dane Buson <da...@unseen.edu> wrote:
> Jasper Janssen <jas...@jjanssen.org> wrote:
> > On Tue, 31 Oct 2006 23:43:52 GMT, "Mike Jacoubowsky"
> > <Mi...@ChainReaction.com> wrote:
> >
> >> valve nuts buzzing.
> >
> > Did a new all-valve-high-end-audio-amplifier get released? That always
> > sets the valve[1] nuts buzzing in the audiophool community.
>
> I'm personally waiting for my Altmann Acoustic Panel to arrive in the
> mail. It's not just wood, Hell no, this is *audiophile* wood.
>
> http://www.ilikejam.dsl.pipex.com/audiophile.htm
What are you going to do with one?
It takes around $6000 to panel a room.
--
Michael Press
Dane Buson
> Dane Buson <da...@unseen.edu> wrote:
>> Jasper Janssen <jas...@jjanssen.org> wrote:
>> > <Mi...@ChainReaction.com> wrote:
>> >
>> >> valve nuts buzzing.
>> >
>> > Did a new all-valve-high-end-audio-amplifier get released? That always
>> > sets the valve[1] nuts buzzing in the audiophool community.
>>
>> I'm personally waiting for my Altmann Acoustic Panel to arrive in the
>> mail. It's not just wood, Hell no, this is *audiophile* wood.
>>
>> http://www.ilikejam.dsl.pipex.com/audiophile.htm
>
> What are you going to do with one?
> It takes around $6000 to panel a room.
But they contrast so well with my Shakti stone electromagnetic stabilizer!
http://www.shakti-innovations.com/audiovideo.htm
--
Dane Buson - sig...@unixbigots.org
Music in the soul can be heard by the universe.
-- Lao Tsu