Tubular rim glue ???

[Carl Fogel]

[email protected] wrote in message news:<[email protected]>...
> John Everett writes:
>
> >> My track riding partner had a crash the other week and is now sporting an artificial shoulder
> >> and the reason for his crash has been identified as the wrong type of glue (as well as not
> >> enough) on his tubular tyre. As I have a Yankee mate that can get tubular glue for me and is
> >> even willing to send it it to me, But has no knowledge of cycling, let alone the noble sport of
> >> track riding. What is a good brand of tubular glue in America? The "multi purpose" glues here
> >> in New Zealand are obviously a bit dodgy.
>
> http://www.engr.ukans.edu/~ktl/bicycle/Cusa1.pdf
>
> I don't know if anybody else found this chart to be weird. In all the years I rode tubulars with
> various types of rim glue, I never had the glue separate from the rim. In fact the build-up on
> rims often became a problem and rim cleaning was in order. So how does the rim material affect how
> tight the tire stays on. It seems to me to be a case of how carefully the tire was uniformly glued
> with a minimum thickness glue film and one that was cured sufficiently.
>
> The whole chart seems odd. There is also no mention of the sample size, method of application and
> pre-cure for the tires. Somehow I don't believe the results shown are anything but a cursory test
> of tenacity of the adhesive to itself, neither tire not rim pulling away with bare patches.
>
> Who did these tests, and what sort of controls were used?
>
> Jobst Brandt [email protected]

Dear Jobst,

Well, the title lists Calvin C. Jones of the Barnett Bicycle Institute and C.S. Howat, Ph.D , P.E.,
of the Chemical and Engineering Dept. of the University of Kansas.

So you might email Professor Howat and ask him for the details. He's still in the university's
contact list at:

http://www.engr.ku.edu/facultystaff/people.php?departmentID=14

Try him at [email protected].

The article states that the charts are a subset of more extensive data and testing that isolated
such things as curing time and mentions cleaning procedures.

Whether the glue fails most often at the tire's base tape or at the rim sounds like a good question.
But your experience in the years that you rode tubulars might differ from the kinds of rims tested
in 1995. After all, these rims were anodized and hard anodized. Do you recall what kind of rims you
were gluing to?

As for why different brands of glue might stick differently to anodized and hard anodized rims, a
long FAQ follows from:

http://www.anodizing.org/faqs.html

that may address the question. Briefly, post-anodizing sealants vary widely. Also, different
anodizing procedures affect porosity, which might matter to glue.

Carl Fogel

from FAQ:

I am trying to glue a rubber grommet to clear anodized aluminum. I am using an industrial grade
instant adhesive on 6061-T6 alloy. The grommet is acting as a mechanical pivot so there is some
amount of force, but not a lot. I am having difficulty getting the adhesive to stick. Do you think
it is the adhesive I am using, or does the sealing of the anodic coating reduce the adhesion? Could
the anodize coating be coming off?

It's probably not the fault of the adhesive and, no, the anodizing is not coming off. You have most
likely touched on the problem in your question. The answer to your problem can be applied across any
number of situations involving the adhesion of bonding agents or organic coatings (paints) over
anodized aluminum. Anodizing can be an excellent surface for these applications, but the anodizing
must be done with this in mind. The solution to your problem involves the method of rinsing and
sealing of the anodic oxide after anodizing.

It is quite common to seal anodic coatings on so-called "proprietary" solutions that contain certain
wetting agents (surfactants). This is done primarily to help prevent the formation of **** on the
surface of the part. **** detracts from the appearance of the product and makes it look dirty or
hazy. If it is known that the anodic coating is to be used as a base for paint, or that adhesives
are going to be used (caulking around windows in an architectural application, for example), the
anodized parts may be sealed in either near-boiling deionized (DI) water or a dilute solution of
commercially available nickel acetate. Sealing with room temperature nickel fluoride is also
acceptable in this case. All three of these methods are free of surfactants. It also helps if the
parts can be thoroughly rinsed in clean DI water before and after the sealing step. This will give a
clean, "non-slippery" surface (no wetting agents) to which paint and most adhesives will bond.
(Anodized aluminum that is to be painted is sometimes left unsealed altogether.) It would also be
advisable to prime the anodized surface prior to applying the adhesive by wiping with a highly
volatile solvent such as methyl ethyl ketone (MEK) or acetone to remove all dirt, fingerprints, and
other possible contaminants.

Of course, you will still have to determine, by testing, which adhesive will give the best service
for your application.

http://www.anodizing.org/faqs.html

 

[Carl Fogel]

[email protected] (Calvin Jones) wrote in message news:<[email protected]>...
> The testing described in the link http://www.engr.ukans.edu/~ktl/bicycle/Cusa1.pdf was performed
> by Dr. Colin Howat at the University of Kansas.
>
> If you want more detail, I suggest you write him directly, see his contact page at
> http://www.engr.ukans.edu/~ktl/contact/contact.html

Dear Calvin,

Ah, the unexpected joys of browsing!

I imagine that your post is a reply to Jobst Brandt's questions about the 1995 article that you and
Professor Howat wrote on tubular glue.

But somehow your post has ended up being indexed (at least for the moment) on my news server under
an utterly unrelated "testing" thread, where people test their latest newsreader mis-configurations.

Glad to see that you're out there, but I was a bit startled to run into you here. Probably it's just
my news server having a bad day. In any case, I'd just posted a reply to Jobst with Professor
Howat's email address, so things should work out.

Carl Fogel

 

[Jobst Brandt]

Carl Fogel writes:

http://www.engr.ukans.edu/~ktl/bicycle/Cusa1.pdf

>> I don't know if anybody else found this chart to be weird. In all the years I rode tubulars with
>> various types of rim glue, I never had the glue separate from the rim. In fact the build-up on
>> rims often became a problem and rim cleaning was in order. So how does the rim material affect
>> how tight the tire stays on. It seems to me to be a case of how carefully the tire was uniformly
>> glued with a minimum thickness glue film and one that was cured sufficiently.
>>
>> The whole chart seems odd. There is also no mention of the sample size, method of application and
>> pre-cure for the tires. Somehow I don't believe the results shown are anything but a cursory test
>> of tenacity of the adhesive to itself, neither tire not rim pulling away with bare patches.
>>
>> Who did these tests, and what sort of controls were used?

> Well, the title lists Calvin C. Jones of the Barnett Bicycle Institute and C.S. Howat, Ph.D ,
> P.E., of the Chemical and Engineering Dept. of the University of Kansas.

Ooh! Facts by association arises again. I'm talking about the content of the article at the URL
listed above. It is mainly a faulted tutorial on how to mount tires rather than a test report. In
fact nothing about the test is described. That is where my doubts arise.

The method of mounting a tubular tells me that these folks are not users or at least not to the
degree that regularly ride tubulars.

> So you might email Professor Howat and ask him for the details. He's still in the university's
> contact list at:

http://www.engr.ku.edu/facultystaff/people.php?departmentID=14

> Try him at [email protected].

> The article states that the charts are a subset of more extensive data and testing that isolated
> such things as curing time and mentions cleaning procedures.

So where is the test report?

> Whether the glue fails most often at the tire's base tape or at the rim sounds like a good
> question. But your experience in the years that you rode tubulars might differ from the kinds of
> rims tested in 1995. After all, these rims were anodized and hard anodized. Do you recall what
> kind of rims you were gluing to?

> As for why different brands of glue might stick differently to anodized and hard anodized rims, a
> long FAQ follows from:

Yes, and the moon might be made of green cheese. These are purely hypotheses while somewhere a test
report should underlie these claims. You'll notice that no explanation of the empirical rules of how
to mount a tubular are given.

Jobst Brandt [email protected]

 

[tros]

[email protected] wrote:
>The method of mounting a tubular tells me that these folks are not users or at least not to the
>degree that regularly ride tubulars.

Does Jobst know any real mechanics (not the rec.bicycles.tech types)? We know he was never a
mechanic himself, never built wheels professionally, never glued tires professionally, never worked
for a team, etc but his credentials really stink when he doesn't even know the names of several-year
national team mechanics like Calvin.

Not that I agree with all the paper's recommendations, for example gluing base tape makes it too
difficult to remove tires from the rim, but for those who lack experience it is an excellent read.

>Yes, and the moon might be made of green cheese. These are purely hypotheses while somewhere a test
>report should underlie these claims. You'll notice that no explanation of the empirical rules of
>how to mount a tubular are given.

Talk about a pot calling the kettle black! Where's the Jobst-job "test report" backing up his
baseless hypothesis that rim glue causes rolling resistance?

If you want a description of how to mount tubulars read Roger Marquis' at
<http://www.roble.net/marquis/tubular>.

Tommy Roster

 

[Tim McNamara]

<[email protected]> writes:

> [email protected] wrote:
>
>>The method of mounting a tubular tells me that these folks are not users or at least not to the
>>degree that regularly ride tubulars.
>
> Does Jobst know any real mechanics (not the rec.bicycles.tech types)? We know he was never a
> mechanic himself, never built wheels professionally, never glued tires professionally, never
> worked for a team, etc but his credentials really stink when he doesn't even know the names of several-
> year national team mechanics like Calvin.

Umm, I was a real mechanic, built wheels professionally, etc. And I don't know who the f**k you're
talking about either. Stop being a troll.

BTW the mere fact that someone is a national team mechanic is not necessarily a credential-
especially if we're talking about the nepotistic family business that USACycling became. Other
national teams and national governing bodies in Europe etc. suffer from the same problems. I
remember a lovely story of Greg LeMond's fabled mechanic, Julian, drilling a hole through the stem
into the bar and screwing in a wood screw to keep the bars from rotating at Paris-Roubaix, reported
by Paul Turner. Sheesh.

> Talk about a pot calling the kettle black! Where's the Jobst-job "test report" backing up his
> baseless hypothesis that rim glue causes rolling resistance?

Well, it's been published for years and the URL has been given many times. Get off your ass and
check it out.

> If you want a description of how to mount tubulars read Roger Marquis' at
> <http://www.roble.net/marquis/tubular>.

Roger, why don't you just post under your real name?

 

[Jobst Brandt]

Tommy Roster writes:

>> The method of mounting a tubular tells me that these folks are not users or at least not to the
>> degree that regularly ride tubulars.

> Does Jobst know any real mechanics (not the rec.bicycles.tech types)? We know he was never a
> mechanic himself, never built wheels professionally, never glued tires professionally, never
> worked for a team, etc but his credentials really stink when he doesn't even know the names of several-
> year national team mechanics like Calvin.

I see you believe the mechanics know more about the technology than the engineers who design the
equipment. I think you'll find that the people who design lunar landers have never been to the moon
or for that matter, people who design race cars are not race car drivers.

> Not that I agree with all the paper's recommendations, for example gluing base tape makes it too
> difficult to remove tires from the rim, but for those who lack experience it is an excellent read.

Why is misinformation "an excellent read"? I find that condescending to people who want to know
the facts.

>> Yes, and the moon might be made of green cheese. These are purely hypotheses while somewhere a
>> test report should underlie these claims. You'll notice that no explanation of the empirical
>> rules of how to mount a tubular are given.

> Talk about a pot calling the kettle black! Where's the Jobst-job "test report" backing up his
> baseless hypothesis that rim glue causes rolling resistance?

I take it you don't read what gets posted here or you would know that is untrue. That you find the
data and curves baseless suggests you don't understand the nature of rolling resistance. It is not
caused by scrubbing on the road as has been the belief (and still is for many).

> If you want a description of how to mount tubulars read Roger Marquis' at
> <http://www.roble.net/marquis/tubular>.

In spite of the "heat in Davis CA" read for comparison:

http://draco.acs.uci.edu/rbfaq/FAQ/8b.28.html

Jobst Brandt [email protected]

 

[Tom Sherman]

Tim McNamara wrote:

> ... BTW the mere fact that someone is a national team mechanic is not necessarily a credential-
> especially if we're talking about the nepotistic family business that USACycling became. Other
> national teams and national governing bodies in Europe etc. suffer from the same problems. I
> remember a lovely story of Greg LeMond's fabled mechanic, Julian, drilling a hole through the stem
> into the bar and screwing in a wood screw to keep the bars from rotating at Paris-Roubaix,
> reported by Paul Turner. Sheesh.

Maybe he had inhaled too much tubular glue fumes.

Tom Sherman - Quad Cities (Illinois Side)

 

[John Dacey]

"Oderint, dum metuant." - Caligula
On Mon, 01 Mar 2004 05:58:33 GMT, [email protected]
wrote:

>John Dacey writes:
>> Shifted upward from where' That's my question. I don't mean to be obtuse, but I cannot glean from
>> this chart precisely where the tubular models would fall if they were otherwise uncompromised by
>> glue losses. That they would be better with shellac I'll accept, but I'm not prescient enough to
>> know exactly how much better.
>
>>> Therefore, Regardless of where they lie in the axes, the best tires don't gain as much from
>>> higher inflation than the slugs that have high losses when the flex. You could rearrange these
>>> tires purely by their curvature and have a correct rating without knowing any absolute values
>>> measured.
>
>>> It was strikingly conspicuous to me why the curves of well known and excellent silk criterium
>>> tires crossed through lesser tires. This finally gave me the answer to my question of why we
>>> have track glue that was almost never used... because no one knew what its real purpose was and
>>> the reasons given didn't convince anyone. The graph put all my prior experience with tubulars
>>> into perspective. I was always aware that tubulars moved on the rim as was evident from the grey
>>> contamination from rim metal, but when I saw the curves it became obvious.
>
>> Not to complicate this further, but it isn't clear to me why movement between tubular and its rim
>> causes rolling resistance to increase. Is the movement the greatest culprit or is it the squish
>> of a layer of cement that doesn't cure to a hardness that's to blame? Safety issues aside, would
>> a tubular blown up to 12 BAR with no rim cement whatsoever have lower rolling resistance yet?
>
>Pressure sensitive glues are plastic and move like thick honey. If you have used tubulars for any
>extensive riding, you will notice that the rim becomes abraded from the base tape of the tire,
>leaving a cloth pattern in the metal. To avoid this, I glued epoxy filled cotton webbing (like
>straps on a backpack) onto mu rims that were rigid and anchored themselves in the spoke sockets to
>which they conformed. This acted as an insulator and made descending steep curvy roads safe. I was
>not as concerned with RR losses as much as safe braking.
>
>>> It makes no difference how old or recent the tests, glue, tires, etc are, the characteristic is
>>> uncontrovertible. I sensed at the time that my assessment would irritate those who ride the
>>> track and anticipated their counter attack after my experience with analyzing stress in wheels
>>> and how they should be built to be reliable.
>
>> The only thing irritating is the absence of specifics. If you lay claim to having the Rosetta
>> Stone that unlocks the Speed Secrets of the Ancients, we just want to know that there's something
>> worth reading hidden there.
>
>The curves, as I explained reveal that unambiguously if you take the time to read the values. As I
>mentioned, even without numbers, these curves could be arranged in order and their valid spacing
>just from their shape. The flattest curves belong at the bottom. The flattest curves are the
>tubulars and they are far from their home level. That is how much road glue eats up in energy.
>There are values in the data and on the graphs.

I don't think you can make the leap you've taken here. There are other possible sources for energy
loss than simply the squirm of road glue. I don't think you've ruled out the possibility that the
bond between the tire's base tape and casing contributes to increased rolling resistance, nor have
you shown that the use of track cement has no loss of its own. Without an accounting of these issues
(perhaps others), assessments of the importance of your "discovery" are premature.

Your suggestion that these values are obvious and that I should be able to calculate this for
myself was disingenuous. Within the time this has been under recent discussion, there have
probably been more successful suitors to solve the riddles of Turandot than have been able to
calculate the rolling resistance differences between road and track rim cements based on your
data. Of the many technically ept readers here, only a single one (Benjamin Weiner) has offered
further speculation and he wisely declined to "eyeball" a new value based on the curves for tires
that were actually measured.

-------------------------------
John Dacey Business Cycles, Miami, Florida http://www.businesscycles.com Now in our twenty-first
year. Our catalog of track equipment: eighth year online
-------------------------------

 

[Mike S.]

<[email protected]> wrote in message
news:[email protected]...
> Tommy Roster writes:
>
> >> The method of mounting a tubular tells me that these folks are not users or at least not to the
> >> degree that regularly ride tubulars.
>
> > Does Jobst know any real mechanics (not the rec.bicycles.tech types)? We know he was never a
> > mechanic himself, never built wheels professionally, never glued tires professionally, never
> > worked for a team, etc but his credentials really stink when he doesn't even know the names of
> > several-year national team mechanics like Calvin.
>
> I see you believe the mechanics know more about the technology than the engineers who design the
> equipment.

I think you'll find that the people who design lunar landers have never been to the moon or for that
matter, people who design race cars are not race car drivers.

One of the things I heard on Speed/Windtunnel the other night with Dale Earnhart Jr. was that
they've scrapped several cars that tested exactly the same as his Daytona-winning car in the tunnel,
etc. but when they got it out on the track, they just didn't go as fast.

I believe that pure numbers don't tell the whole story when you get product X out in the real world.
Another case in point: the Kirk Magnesium frame. Neat idea but they rode like ****, and broke.

Yes, testing and engineering have lots to do with making things work, but that's why they have field
trials of new equipment too.
>
> > Not that I agree with all the paper's recommendations, for example gluing base tape makes it
> > too difficult to remove tires from the rim, but for those who lack experience it is an
> > excellent read.
>
> Why is misinformation "an excellent read"? I find that condescending to people who want to know
> the facts.
>
> >> Yes, and the moon might be made of green cheese. These are purely hypotheses while somewhere a
> >> test report should underlie these claims. You'll notice that no explanation of the empirical
> >> rules of how to mount a tubular are given.
>
> > Talk about a pot calling the kettle black! Where's the Jobst-job "test report" backing up his
> > baseless hypothesis that rim glue causes rolling resistance?
>
> I take it you don't read what gets posted here or you would know that is untrue. That you find the
> data and curves baseless suggests you don't understand the nature of rolling resistance. It is not
> caused by scrubbing on the road as has been the belief (and still is for many).
>
> > If you want a description of how to mount tubulars read Roger Marquis' at
> > <http://www.roble.net/marquis/tubular>.
>
> In spite of the "heat in Davis CA" read for comparison:
>
> http://draco.acs.uci.edu/rbfaq/FAQ/8b.28.html
>
> Jobst Brandt [email protected]

 

[Jp]

"David L. Johnson" <[email protected]> wrote in message news:<[email protected]>...
> Functionally, the casing ends at the point of rim contact, whether that contact is secured by glue
> or bead.

And that point on a clincher is functionally the sidewall of the tire. A clincher is supported by
the rim on the sidewall, a tubular is not. That could account for the difference in rolling
resistance. I clincher is functionally lower profile, for an equivalent tire.

> The reason that tubulars don't get as many pinch flats at a given pressure, and the only reason
> they can be run at lower pressure than clinchers, is that the rim edge is wider.

I thought they didn't get pinch flats at all because there was nothing for them to get pinched
between. I thought the reason they could be run at lower pressures was because they don't need air
pressure to force them onto the flanges of the rim.

> Yes, they can be lighter, both the rims and the tires (though the tires can be only slightly
> lighter than an equivalently-constructed kevlar bead clincher + tube). The rims can be lighter
> since they do not have to deal with the tire pressure on the flanges that clincher rims do,

And because they don't even have flanges.

JP

 

[Carl Fogel]

[email protected] wrote in message news:<[email protected]>...
> Carl Fogel writes:
>
> http://www.engr.ukans.edu/~ktl/bicycle/Cusa1.pdf
>
> >> I don't know if anybody else found this chart to be weird. In all the years I rode tubulars
> >> with various types of rim glue, I never had the glue separate from the rim. In fact the build-
> >> up on rims often became a problem and rim cleaning was in order. So how does the rim material
> >> affect how tight the tire stays on. It seems to me to be a case of how carefully the tire was
> >> uniformly glued with a minimum thickness glue film and one that was cured sufficiently.
> >>
> >> The whole chart seems odd. There is also no mention of the sample size, method of application
> >> and pre-cure for the tires. Somehow I don't believe the results shown are anything but a
> >> cursory test of tenacity of the adhesive to itself, neither tire not rim pulling away with bare
> >> patches.
> >>
> >> Who did these tests, and what sort of controls were used?
>
> > Well, the title lists Calvin C. Jones of the Barnett Bicycle Institute and C.S. Howat, Ph.D ,
> > P.E., of the Chemical and Engineering Dept. of the University of Kansas.
>
> Ooh! Facts by association arises again. I'm talking about the content of the article at the URL
> listed above. It is mainly a faulted tutorial on how to mount tires rather than a test report. In
> fact nothing about the test is described. That is where my doubts arise.
>
> The method of mounting a tubular tells me that these folks are not users or at least not to the
> degree that regularly ride tubulars.
>
> > So you might email Professor Howat and ask him for the details. He's still in the university's
> > contact list at:
>
> http://www.engr.ku.edu/facultystaff/people.php?departmentID=14
>
> > Try him at [email protected].
>
> > The article states that the charts are a subset of more extensive data and testing that isolated
> > such things as curing time and mentions cleaning procedures.
>
> So where is the test report?
>
> > Whether the glue fails most often at the tire's base tape or at the rim sounds like a good
> > question. But your experience in the years that you rode tubulars might differ from the kinds of
> > rims tested in 1995. After all, these rims were anodized and hard anodized. Do you recall what
> > kind of rims you were gluing to?
>
> > As for why different brands of glue might stick differently to anodized and hard anodized rims,
> > a long FAQ follows from:
>
> Yes, and the moon might be made of green cheese. These are purely hypotheses while somewhere a
> test report should underlie these claims. You'll notice that no explanation of the empirical rules
> of how to mount a tubular are given.
>
> Jobst Brandt [email protected]

Dear Jobst,

Actually, I notice that you ignored my question about when you rode tubulars and whether your
tubular rims were anodized, hard anodized, or polished:

> > Whether the glue fails most often at the tire's base tape or at the rim sounds like a good
> > question. But your experience in the years that you rode tubulars might differ from the kinds of
> > rims tested in 1995. After all, these rims were anodized and hard anodized. Do you recall what
> > kind of rims you were gluing to?

Perhaps I'm wrong, but my impression is that you switched to clinchers quite a few years ago. If you
did stop riding tubulars, when did you stop?

Were (or are) your tubular rims polished, anodized, hard anodized, or what?

If you stopped riding tubulars, did you continue researching them? I'm just curious whether you're
posting about current methods and materials from continuing experience, or from keeping up with the
subject by reading, or about the way things were ten or twenty or thirty years ago.

Do you know of any other tubular glue studies that contradict what Professor Howat and Calvin
Jones reported?

Have you emailed Professor Howat and asked whatever questions are on your mind? Again, his email
address is [email protected].

Carl Fogel

 

[Tom Compton]

John Dacey wrote:
> I don't want to resurrect the whole clincher/tubular debate. The original poster inquired about
> track tires, where tubulars are still the predominant format. I request again: can you estimate
> the time difference in a flying kilometer time trial ridden at 50kph, where the only difference is
> whether shellac or modern road rim cement is used to adhere the tires? Just how many seconds (or
> fractions thereof) per kilometer is shellac (track glue) likely to be worth?

Assume 25 gmf savings for gluing with a hard glue (a guesstimate based on the data from Brandt's
table of tire rolling resistance). This corresponds to about 0.0003 change in tire rolling
resistance ( http://www.analyticcycling.com/ForcesSource_Page.html ) or about 0.02 seconds in a
flying 200 (sorry, not the flying kilo for which you asked).

Flying 200 analysis: http://www.analyticcycling.com/Fly200_Page.html

Regards,

Tom Compton www.AnalyticCycling.com

 

[Jp]

"David L. Johnson" <[email protected]> wrote in message news:<[email protected]>...
> On Thu, 04 Mar 2004 03:55:22 -0800, JP wrote:
>
> > "David L. Johnson" <[email protected]> wrote in message
> > news:<[email protected]>...
> >> Functionally, the casing ends at the point of rim contact, whether that contact is secured by
> >> glue or bead.
> >
> > And that point on a clincher is functionally the sidewall of the tire. A clincher is supported
> > by the rim on the sidewall, a tubular is not.
>
> In terms of usual flex, the tubular is supported at the edge of the rim, because that is where the
> flex is prevented by the fact that it is in contact with the rim (aside from the squirm we are
> talking about).

More or less. I think it would be more accurate to think in terms of the rim damping the flex, but
the tire flexs over its entire circumference.

> >That could account for the difference in rolling resistance. I clincher is functionally lower
> >profile, for an equivalent tire.
>
> No, the edge of both rims would contact the tires in the same point of their sides. That would be
> part of the idea of an equivalent tire.

Not my idea of an equivalent tire. My idea of an equivalent tire would be same width and same
construction material where applicable (disregarding bead, base tape, sewup thread, etc.). The
flange of the clincher rim provides an external brace for the tire, not a large one by any means,
but perhaps enough to account for the difference in rolling resistance.

> >> The reason that tubulars don't get as many pinch flats at a given pressure, and the only reason
> >> they can be run at lower pressure than clinchers, is that the rim edge is wider.
> >
> > I thought they didn't get pinch flats at all because there was nothing for them to get pinched
> > between.
>
> The rim is still there. They do, reportedly, get pinch flats,

If you say so. It sounds preposterous to me, and this is the first I have ever heard of it. Really
beside the point of whether the flange of a clincher rim might brace the tire and reduce rolling
resistance, though.

> but it is not as easy as with a clincher -- though I have not had trouble with clinchers pinch-
> flatting.
>
> > I thought the reason they could be run at lower pressures was because they don't need air
> >pressure to force them onto the flanges of the rim.
>
> A clincher is held onto the rim with very little pressure -- or else you could never inflate it
> without the tube popping. Think about when you stop inflating to check that the bead is seated.
> That is only a few pounds of pressure.

Not that I really pump up clinchers that often, but I get your point. And it seems flawed to me. I
think that the amount of air it takes to hold a light clincher on its rim when it's not being used
is a lot less than the amount required to hold it on the rim when someone is sitting on the bike and
it's being ridden.

JP

 

[Jobst Brandt]

Carl Fogel writes:

> Actually, I notice that you ignored my question about when you rode tubulars and whether your
> tubular rims were anodized, hard anodized, or polished:

>>> Whether the glue fails most often at the tire's base tape or at the rim sounds like a good
>>> question. But your experience in the years that you rode tubulars might differ from the kinds of
>>> rims tested in 1995. After all, these rims were anodized and hard anodized. Do you recall what
>>> kind of rims you were gluing to?

> Perhaps I'm wrong, but my impression is that you switched to clinchers quite a few years ago. If
> you did stop riding tubulars, when did you stop?

I don't recall now but the rims I rode were Fiamme and Mavic and were all poised with no
anodizing. In those days no one would think of anodizing aluminum rims. From the mid 1960's on, I
glued my tires on insulators that I applied to the rims because melting glue had always been a
serious problem around here and in the Alps. This is especially true on dirt roads that are steep
because speed is not high enough to lose much energy to air resistance. Besides, at lower speed
cooling is worse.

I have described the process of applying the epoxied cotton webbing to the rims here often.

> If you stopped riding tubulars, did you continue researching them? I'm just curious whether you're
> posting about current methods and materials from continuing experience, or from keeping up with
> the subject by reading, or about the way things were ten or twenty or thirty years ago.

No one has made any better tires that the top of the line in the end of widespread use of them.

> Do you know of any other tubular glue studies that contradict what Professor Howat and Calvin
> Jones reported?

I don't know what his results are because no mention of failure mode was mentioned. The biggest
problem with tubulars is melting on descents. The ancients I talked to all mentioned this. Mr.
Cinelli remembered it well and had no great solutions for it, all pressure sensitive glues being
thermally affected.

> Have you emailed Professor Howat and asked whatever questions are on your mind? Again, his email
> address is [email protected].

Yes.

Jobst Brandt [email protected]

 

[tros]

David L. Johnson <[email protected]> wrote:
>Sorry to butt into what appears to be a private discussion, but can you explain the advances that
>the tubular-tire industry has made in the past 20 years?

Clearly, it's been some time since you've used tubbies. Otherwise you'd know that today's tires are
far more reliable. Clement criterium Setas may have been the best in their day but nearly any
tubular made by Vittoria today is several times better. Sidewall cuts are now almost non-existant
and treads commonly wear down to the casing. Still not as reliable as some clinchers but more
reliable by weight than any clincher made today or any tubular made 20 years ago.

>I raced back in what were the glory days of such tires.

So why are you basing your opinion of tubulars on such outdated information?

Tommy Roster

 

[tros]

David L. Johnson <[email protected]> wrote:
>I think you are talking about two different things. The casing above the bead on a clincher reacts
>equivalently to the casing away from the rim on a tubular.

This is pure speculation, based on a seriously flawed understanding of tire casing material and cross-
section. The difference between tubular and clincher casings is as different as auto radial and bias
plys. If you have evidence to the contrary please do present it.

Tommy Roster

 

[Tom Sherman]

David L. Johnson wrote:

> ... Sorry to butt into what appears to be a private discussion, but can you explain the advances
> that the tubular-tire industry has made in the past 20 years? I raced back in what were the glory
> days of such tires. When I got back on the bike in the mid '90s, I certainly saw no improvement in
> tubular technology. The glues were precisely the same brands available 30 years ago, and if they
> changed their formulas, they were not talking about
> it. The tires were a mere shadow of what was available in 1970. We all trained on silk tires --
> even as college students. Cotton were regarded, rightly, as inferior. No one would think of
> racing on them. Now a lightweight cotton is about as good as you can get.
>
> The only innovation would be aramid and other synthetic casing. But none of them are superior to
> silk, by anyone's estimation.
>
> If anything, the tubular tire technology has been in steady decline since about 1975-1980, when
> decent clinchers began appearing and the bottom fell out of the market. If Jobst's study is out of
> date, it is only in that the tubulars available now could not measure up to what he used.

I wonder if some manufacturers are stopping producing tubular tires for street use due to liability
reasons. The legal cost alone of setting a single lawsuit would likely be more than the yearly
profit from tubular sales.

Tom Sherman - Quad Cities (Illinois Side)

 

[Jobst Brandt]

Tommy Roster writes:

>> Sorry to butt into what appears to be a private discussion, but can you explain the advances that
>> the tubular-tire industry has made in the past 20 years?

> Clearly, it's been some time since you've used tubbies. Otherwise you'd know that today's tires
> are far more reliable. Clement criterium Setas may have been the best in their day but nearly any
> tubular made by Vittoria today is several times better. Sidewall cuts are now almost non-existant
> and treads commonly wear down to the casing. Still not as reliable as some clinchers but more
> reliable by weight than any clincher made today or any tubular made 20 years ago.

Would you expand on that. Sidewall cuts are something all bare sided tire, tubulars or clinchers
don't sustain. What causes the sidewall cuts to which you refer. The many years of riding on
tubulars that I did, didn't cause any sidewall cuts. How do you get them?

In the days of yore, tubulars had a fine bias ply belt under the tread that would show a short
distance before the cords were on the road themselves. My big problem with them were that a nail
or thorn required opening the tire, patching, sewing, and re-gluing the base tape with latex
emulsion. I just gave my last three 1pt jars of latex emulsion (Jiffytex) to Dave Prion at the
Bicycle Outfitter, where there still is need for it. There are riders today who don't patch their
tubulars, they bring them to the bicycle shop for repairs. Of these, the ones I saw were worth
throwing away even though they were essentially new. These guys have money but it won't buy the
tires we used to have.

>> I raced back in what were the glory days of such tires.

> So why are you basing your opinion of tubulars on such outdated information?

I've seen the tires of today and agree that they are poor replicas of something that was once an
art. I don't thin there are many people around today that ride the track on 110g Clement Tipo 00
tires, or road rider who ride criteriums on 220g tires. These tire would work with more pressure
than I care to ride on. The weight is a good indication of the rolling resistance.

I think you are not aware of the tires you imagine were poorer than those available today.

Jobst Brandt [email protected]

 

[Carl Fogel]

[email protected] wrote in message news:<[email protected]>...
> Carl Fogel writes:
>
> > Actually, I notice that you ignored my question about when you rode tubulars and whether your
> > tubular rims were anodized, hard anodized, or polished:
>
> >>> Whether the glue fails most often at the tire's base tape or at the rim sounds like a good
> >>> question. But your experience in the years that you rode tubulars might differ from the kinds
> >>> of rims tested in 1995. After all, these rims were anodized and hard anodized. Do you recall
> >>> what kind of rims you were gluing to?
>
> > Perhaps I'm wrong, but my impression is that you switched to clinchers quite a few years ago. If
> > you did stop riding tubulars, when did you stop?
>
> I don't recall now but the rims I rode were Fiamme and Mavic and were all poised with no
> anodizing. In those days no one would think of anodizing aluminum rims. From the mid 1960's on, I
> glued my tires on insulators that I applied to the rims because melting glue had always been a
> serious problem around here and in the Alps. This is especially true on dirt roads that are steep
> because speed is not high enough to lose much energy to air resistance. Besides, at lower speed
> cooling is worse.
>
> I have described the process of applying the epoxied cotton webbing to the rims here often.
>
> > If you stopped riding tubulars, did you continue researching them? I'm just curious whether
> > you're posting about current methods and materials from continuing experience, or from keeping
> > up with the subject by reading, or about the way things were ten or twenty or thirty years ago.
>
> No one has made any better tires that the top of the line in the end of widespread use of them.
>
> > Do you know of any other tubular glue studies that contradict what Professor Howat and Calvin
> > Jones reported?
>
> I don't know what his results are because no mention of failure mode was mentioned. The biggest
> problem with tubulars is melting on descents. The ancients I talked to all mentioned this. Mr.
> Cinelli remembered it well and had no great solutions for it, all pressure sensitive glues being
> thermally affected.
>
> > Have you emailed Professor Howat and asked whatever questions are on your mind? Again, his email
> > address is [email protected].
>
> Yes.
>
> Jobst Brandt [email protected]

Dear Jobst,

I sympathize with your honest don't-recall reply, since I'm terrible at remembering when things
happened or changed:

"I don't recall now but the rims I rode were Fiamme and Mavic and were all poised [polished?] with
no anodizing. In those days no one would think of anodizing aluminum rims. From the mid 1960's on, I
glued my tires on insulators . . ."

Here's what the chronology looks like to me:

The mid-1960's, when you began gluing your tires on insulators to solve glue-melting tubular
problems, were forty years ago.

Cino Cinelli retired in 1978, twenty-six years ago.

Your clincher and tubular tire rolling resistance graph is from 1986, eighteen years ago.

The article by Professor Howat and Calvin Jones is from 1995, nine years ago.

Parts of the BikePro site are dated 1997, seven years ago.

In October of 2001, you wrote that when it comes to cornering:

"My vote is on the Avocet Road that I designed to replace the Clement Campionato del Mundo tubular
that served us so well before their demise. I have not been disappointed and never want to go back
to tubulars after repairing them for more than 20 years and having their glue melt on steep
descents."

http://groups.google.com/groups?selm=ZCQx7.4755%24no1.54439%40typhoon.sonic.net&output=gplain

While you gave no date in the post about never wanting to go back to tubulars again, it sounds as if
you stopped using tubulars at least as far back as the appearance of the Avocet Road clincher model.

You may be perfectly correct in your doubts about the glue study, but there's also the possibility
that glues and rim materials have changed since those days and that newer glues and different rim
materials might behave differently than you expect.

After all, from what you've been saying in this thread, you stopped using tubulars before the
widespread anodizing of rims and the general reduction of tubulars to track applications.

I hope that Professor Howat still has the data and can clear up your questions, but I wouldn't be
surprised if nine-year-old data is now out of date. The materials world seems to be obsessed with
change and improvement.

Nor would I be surprised if your skepticism turns out to be perfectly correct, whatever its
specifics may be.

I'm just not willing to trash what seems like a reasonable study of how well glue sticks to
anodized, hard anodized, and carbon rims without specific evidence, preferably even more recent than
the study in question.

Like most of the people who've been posting in this thread, I don't want much--just clear, complete
tables showing extensive recent test results for any subject uder the sun that interests me.

Alas, practical limits often leave us wondering about the things that we'd most like to see
tested. Real testing is much harder than theorizing and quibbling, which is what we love to do
here on rec.bicycles.tech, whether it's how well glue sticks to rims, how easily glued tires roll
compared to shellac, how long an anodized rim takes to lose how much stiffness, or actual data on
spoke fatigue:

"The fatigue resistance of spokes was not tested for lack of suitable equipment." --The Bicycle
Wheel, "Part III, Equations and Tests"

I hope that you can get some answers from Professor Howat and share them with us.

Carl Fogel

 

[Carl Fogel]

"David L. Johnson" <[email protected]> wrote in message news:<[email protected]>...
> On Thu, 04 Mar 2004 11:32:22 -0800, Carl Fogel wrote:
>
> > If you stopped riding tubulars, did you continue researching them? I'm just curious whether
> > you're posting about current methods and materials from continuing experience, or from keeping
> > up with the subject by reading, or about the way things were ten or twenty or thirty years ago.
>
> Sorry to butt into what appears to be a private discussion, but can you explain the advances that
> the tubular-tire industry has made in the past 20 years? I raced back in what were the glory days
> of such tires. When I got back on the bike in the mid '90s, I certainly saw no improvement in
> tubular technology. The glues were precisely the same brands available 30 years ago, and if they
> changed their formulas, they were not talking about
> it. The tires were a mere shadow of what was available in 1970. We all trained on silk tires --
> even as college students. Cotton were regarded, rightly, as inferior. No one would think of
> racing on them. Now a lightweight cotton is about as good as you can get.
>
> The only innovation would be aramid and other synthetic casing. But none of them are superior to
> silk, by anyone's estimation.
>
> If anything, the tubular tire technology has been in steady decline since about 1975-1980, when
> decent clinchers began appearing and the bottom fell out of the market. If Jobst's study is out of
> date, it is only in that the tubulars available now could not measure up to what he used.

Dear David,

The more, the merrier--you join me, Jobst, Tim McNamara, Tommy Roger, Tom Sherman, Mike S., John
Dacey, and others, so it's hardly private.

Sadly, I'm not the one to explain advances in tubulars over the last thirty or forty years. I'm just
fascinated with the odd details in what seems like a small and hotly debated area.

Briefly, two of the topics we're thrashing with more heat than light include whether hard shellac
rolls faster than glue (no direct data has been mentioned so far, just theories and extrapolation)
and whether various glues stick better or worse to different kinds of rims (anodized, hard anodized,
and carbon are mentioned in a study that's being questioned).

There may have been no significant changes, as you suggest, in tubulars, rims, and glue since
tubulars fell out of favor decades ago.

But the study that's being questioned addresses how well glues stick to three kinds of rim
materials that may not have been in use twenty or thirty years ago. Even without going into the
details of anodizied and carbon rims, it seems plausible that glue might stick diffferently to
different surfaces.

As for whether the glues are the same after several decades, I don't know of anyone who's actually
checked with the manufacturers. You may be right that glues today are exactly the same as they were
decades ago, but the rims that the glue sticks to have pretty much turned to anodizing.

Earlier in this thread, I posted a link to an anodizing group's FAQ about why-doesn't-glue-stick-to-anodized-
surfaces? What we mistakenly think of as only two surfaces (anodized and hard anodized) turns out to
be annoyingly varied. There's more to it than just dunking it in a vat of acid and flipping the
electric switch.

Seat-of-the-pants testing is notoriously unreliable, silent changes are common in manufacturing, and
so are unnoticed changes, so I'm cautious about your notion of no-change in tubulars. I'm not
doubting your sincerity or honesty, nor snarling that you must be a fool or a liar--after all, you
may well be right. But it's surprising how blind we can be to changes that make, after all, only a
small difference.

In the current not-all-mavic-rims-suck thread, for example, I was startled to find that Damon Rinard
(as experienced, curious, careful, and sensible a bicycle enthusiast as you can name) simply lumped
three different sub-models of the fabled Mavic MA2 rim together in his weight table, not realizing
that Mavic sold three kinds of eyelets that accounted for most of the weight disparities.

(I must add that I'm not attacking Damon, whom I admire for his extensive efforts to test things
for our benefit. Testing is much harder than the kind of chattering that you're reading at this
very moment.)

Jobst's study, of course, was not a direct glue stickiness study. He set out to measure rolling
resistance in both clinchers and tubulars. From the curves plotted off detailed data points
available elsewhere at the same site, he has theorized about glue effects and possibly extrapolated
this to shellac.

Jobst's theories strike me as quite plausible. And I'm baffled by claims that his test was somehow
designed to favor one tire brand--how can you design a rolling drum to favor one label over another?

The theories that he derives from the relative curves of the two tubular tires versus the clinchers
are less convincing. True, glue seems like the obvious suspect, but tubulars differ from clinchers
in other ways, include rims, base tape, and general construction.

I wish that we had a test that somehow compared the same tire as both a tubular and clincher and
somehow isolated the glue, the base tape, the rim, and everything else.

But I doubt that this test will ever be happen, so we'll just have to do the best we can, raising
questions and trying to answer them. Jobst did us all a service with his 1986 rolling resistance
study. So did Howat and Jones with their 1995 tubular glue study. Neither study deserves the kind of
surprising ill-will that we've seen.

As for good silk tubulars, John Dacey will happily sell you some silks in pink or black from
Andre Dugast:

http://www.businesscycles.com/trcomp.htm#tires

Over the last thirty years, it's possible that the track crowd has seen cotton tubulars improve to
the point that they've driven silk out. Or maybe silk as a general tire is just too expensive for
such a small market to support, so it's now limited to fanatics. Do you know of any recent studies
of the performance difference between current cotton and silk tubulars?

Carl Fogel