Re: Tubular rim glue ???

[psycholist]

"David L. Johnson" <[email protected]> wrote in message
news[email protected]...
> On Tue, 01 Feb 2005 09:27:22 -0500, psycholist wrote:
>
>> <[email protected]> wrote in message
>> news:[email protected]...
>>> Just found a new article on tubular tire adhesives, this time including
>>> carbon rims.
>>>
>>> http://www.engr.ku.edu/~ktl/bicycle/bicycle.html
>>>
>>> It's part 7 in the series by Howat and Jones.
>>> "Howat: Tubular Tires: Tubular Tire Adhesion to Carbon Fiber Rims.
>>> (Part 7)"
>
> Seven "parts" on how to glue tires? Can you say obsessive?
>
>> questions. The way my LBS is mounting tubular tires, he's probably going
>> to
>> end up getting someone seriously hurt and getting himself sued.
>> (According
>> to him, slap a little glue on the rim and the tire, mount it up and in 20
>> minutes you're good to go.)
>
> For one thing, your bike shop should not be mounting tires, you should be.
> It's your butt on the line, anyway. You decide how much glue to use.
>
> --
>
> David L. Johnson
>
> __o | It is a scientifically proven fact that a mid life crisis can
> _`\(,_ | only be cured by something racy and Italian. Bianchis and
> (_)/ (_) | Colnagos are a lot cheaper than Maserattis and Ferraris. --
> Glenn Davies

OK wiseass. The very reason I'm reading this stuff is that I don't believe
my LBS should be mounting tubular tires ... or any tires, either. And I
especially don't think he should be doing it wrong. But he IS mounting them
for a number of people I know. And based on the preponderance of the things
I'm reading, he's not doing a very good job.

He's not touching mine. I'm doing my homework on the internet to learn the
right way to do it. Unfortunately, it's been worse than the helmet debate.
There are a zillion opinions on what is the right way versus what ways are
adequate versus what ways are inadequate to mount tubular tires. Then there
are the folks who are just plain jerks who blurt out something stupid that's
of no value to the discussion.
--
Bob C.

"Of course it hurts. The trick is not minding that it hurts."
T. E. Lawrence (of Arabia)

 

[psycholist]

"Tom Sherman" <[email protected]> wrote in message
news:[email protected]...
> psycholist wrote:
>
>> <[email protected]> wrote in message
>> news:[email protected]...
>>
>>>Just found a new article on tubular tire adhesives, this time including
>>>carbon rims.
>>>
>>>http://www.engr.ku.edu/~ktl/bicycle/bicycle.html
>>>
>>>It's part 7 in the series by Howat and Jones.
>>>"Howat: Tubular Tires: Tubular Tire Adhesion to Carbon Fiber Rims.
>>>(Part 7)"
>>>
>>
>>
>> Dianne,
>>
>> Thank you for posting this link. I'm new to tubulars and it answered
>> many questions. The way my LBS is mounting tubular tires, he's probably
>> going to end up getting someone seriously hurt and getting himself sued.
>> (According to him, slap a little glue on the rim and the tire, mount it
>> up and in 20 minutes you're good to go.)...
>
> A certain service oriented, bike shop owner who is a rec.bicycles.tech
> regular apparently mounts tubular tires successfully within this timeframe
> <http://www.yellowjersey.org/frontwheel.html>.
>
> --
> Tom Sherman - Earth

Tom,

Thanks for that link. I visited that website and read the info there. One
observation. If you read the posts on this thread from Jobst, there are
concerns that tires can roll off on fast descents and under high brake loads
where rims can be heated to 140 degrees or so. I have high-speed descents
with switchbacks in my area. I can't think of too many in Wisconsin where
the guy you linked to is gluing up tires.

Just an observation.

--
Bob C.

"Of course it hurts. The trick is not minding that it hurts."
T. E. Lawrence (of Arabia)

 

[[email protected]]

Peter Chisholm writes:

> Clinchers are for Nancys

....or for girlymen, as our California governor might add.

Jobst Brandt
[email protected]

 

[[email protected]]

JP replies anonymously:

>>> Hmmm, let's see: logic would suggest that despite people largely
>>> giving up on tubulars, glues wouldn't have gotten any worse, so
>>> they could only get better or stay the same. I think Jobst gave
>>> up on tubulars in the early 70s; it is extremely unimaginative to
>>> assume that in thirty years there have been no advances in
>>> adhesives that could be applied to gluing tubulars. Maybe you
>>> should go read the report yourself. FastTack tests mediocre at
>>> best. I'll even go further: when I first heard of using FastTack,
>>> about 1980, maybe it _was_ the best thing available.

>> Stop Hmmming and give it some thought. Tubular track glue was as
>> good as it gets and is still the same.

> No one was talking about track glue. It is utterly irrelevant to
> this discussion.

"glues wouldn't have gotten any worse" are your words, not mine.
Glues for tubular tires have not gotten better for the reasons I
mentioned.

>> Tubular road glue must meet the same criteria it did 50 years ago,
>> that of being tacky enough to adhere to a tire when putting on a
>> spare and be rigid and adhesive enough to keep a tire from
>> creeping. These two requirements have not changed and that such
>> adhesives are temperature sensitive has also remained constant.
>> Instead of hypothesizing, how about speaking from experience and
>> results.

> I'm not hypothesizing in my fundamental statement of fact: that
> according to the published experimental data, there is at least one
> road glue that is as good or better on a rim heated by braking than
> many glues are at normal temperature. Whether that glue existed in
> its present form at the time you were using tubulars is subject
> _only_ to hypothesizing (unless you happen to have a thirty year old
> tube of it that you would be willing to test against the current
> formula), and the two possible hypotheses are: (1) it did not exist
> in its current form, and that is the reason for your negative
> experience with tubular glues under alpine conditions. (2) It did
> exist then, you don't know what you are talking about, and have been
> spreading BS about tubular glues and rim heating for thirty years as
> a result of your inadequate experience with tubular glues. Since I
> don't think you are an idiot, I have gone with hypothesis #1;
> however, if you insist that glues have not changed and yet we have
> experimental evidence that there is one glue that retains more than
> adequate strength under extended downhill braking, we may have to
> reconsider. One thing of which there is no doubt: your experience
> with softening glue is either wrong, dated or simply too limited.

Your stance is hypothesizing. Now you are asking me to do research to
prove your hypothesis. I should ask, do you ride tubulars on a
regular basis now and if not, why not? As I mentioned, those of us
who suffered under those tires are glad where they are today, a relic
of the past.

> My second hypothesis is that FastTack may have been the best glue 25
> years ago. We have experimental data that shows it to be only
> mediocre now. While it would not be the first time that "common
> knowledge" of cycling technology turned out to be nothing but
> superstition, I am giving all of us who used FastTack the benefit of
> the doubt and suggesting that it may have had an advantage at some
> point. That would also indirectly support the earlier hypothesis #1
> that glues have indeed improved over the course of thirty years.

I haven't used Fast Tack (TM) but have used most of the bicycle tire
specific glues and found them inadequate for the reasons mentioned.

http://www.aircraftspruce.com/catalog/appages/fasttack.php
http://tinyurl.com/5a2jh

> In summary, as I said, glues would not get worse, they would stay
> the same or get better. There is at least indirect evidence that
> they might have improved; there is strong direct evidence that with
> the right glue selection rim heating need not be a major concern (at
> least on alloy rims). Certainly, adhesives technology in general
> has had huge advances in thirty years- I just don't understand why
> anyone would feel the need to insist that tubular glues could not
> have improved the modest amount needed to show the experimental
> results noted.

First you claim not to be hypothesizing and then write: "My second
hypothesis is..." I notice you use the subjunctive in true
hypothetical style. Keep up the good posture!

Jobst Brandt
[email protected]

 

[David L. Johnson]

On Wed, 02 Feb 2005 11:34:43 -0500, psycholist wrote:

> OK wiseass. The very reason I'm reading this stuff is that I don't believe
> my LBS should be mounting tubular tires ... or any tires, either. And I
> especially don't think he should be doing it wrong. But he IS mounting them
> for a number of people I know. And based on the preponderance of the things
> I'm reading, he's not doing a very good job.

It's not "wrong" just because it does not follow the rituals you read
about on the Web. Whether or not you think I was contributing anything
of value to the discussion, the fact is that I used tubulars for years,
and never bothered with such things as four separate coats before
mounting the first tire, leaving each one to dry for 24 hours, and
all that rot. You quickly learn not to try to mount a new tire without
pre-stretching it, and you learn not to put a tire on with wet glue.

If you want to follow these arcane rituals, it probably won't hurt. But
it's not necessary, either. No, it will not make you safer. If there
is enough glue to keep the tire from creeping, that is it. Beyond
that you are just making the tire harder to remove.

That 7-part instruction manual mentioned on this thread was way off base.
For one thing, the pictures they showed of Clement glue on carbon rims was
way over the top. They must have used two tubes for each rim. Way too much.

My experience was that, as long as there was a good layer on the tire, and
layer on the rim, it'd stick. The only time I rolled a tire was on a long
descent, with panniers on the back. More glue would not have helped that
situation.

--

David L. Johnson

__o | When you are up to your ass in alligators, it's hard to remember
_`\(,_ | that your initial objective was to drain the swamp. -- LBJ
(_)/ (_) |

 

[Tom Sherman]

psycholist wrote:

> "Tom Sherman" <[email protected]> wrote in message
> news:[email protected]...
>
>>psycholist wrote:
>>
>>
>>><[email protected]> wrote in message
>>>news:[email protected]...
>>>
>>>
>>>>Just found a new article on tubular tire adhesives, this time including
>>>>carbon rims.
>>>>
>>>>http://www.engr.ku.edu/~ktl/bicycle/bicycle.html
>>>>
>>>>It's part 7 in the series by Howat and Jones.
>>>>"Howat: Tubular Tires: Tubular Tire Adhesion to Carbon Fiber Rims.
>>>>(Part 7)"
>>>>
>>>
>>>
>>>Dianne,
>>>
>>>Thank you for posting this link. I'm new to tubulars and it answered
>>>many questions. The way my LBS is mounting tubular tires, he's probably
>>>going to end up getting someone seriously hurt and getting himself sued.
>>>(According to him, slap a little glue on the rim and the tire, mount it
>>>up and in 20 minutes you're good to go.)...
>>
>>A certain service oriented, bike shop owner who is a rec.bicycles.tech
>>regular apparently mounts tubular tires successfully within this timeframe
>><http://www.yellowjersey.org/frontwheel.html>.
>>
>>--
>>Tom Sherman - Earth
>
>
> Tom,
>
> Thanks for that link. I visited that website and read the info there. One
> observation. If you read the posts on this thread from Jobst, there are
> concerns that tires can roll off on fast descents and under high brake loads
> where rims can be heated to 140 degrees or so. I have high-speed descents
> with switchbacks in my area. I can't think of too many in Wisconsin where
> the guy you linked to is gluing up tires.

There are very steep roads in western Dane County, and some tight
corners. However the elevation changes are much less than the Alps,
Rockies, Sierra Nevada’s, etc.

--
Tom Sherman - Earth

 

[David L. Johnson]

On Wed, 02 Feb 2005 08:05:54 -0800, SocSecTrainWreck wrote:

> I'm not hypothesizing in my fundamental statement of fact: that
> according to the published experimental data, there is at least one
> road glue that is as good or better on a rim heated by braking than
> many glues are at normal temperature. Whether that glue existed in its
> present form at the time you were using tubulars is subject _only_ to
> hypothesizing (unless you happen to have a thirty year old tube of it
> that you would be willing to test against the current formula), and the
> two possible hypotheses are: (1) it did not exist in its current form,
> and that is the reason for your negative experience with tubular glues
> under alpine conditions. (2) It did exist then, you don't know what you
> are talking about, and have been spreading BS about tubular glues and
> rim heating for thirty years as a result of your inadequate experience
> with tubular glues. Since I don't think you are an idiot, I have gone
> with hypothesis #1; however, if you insist that glues have not changed
> and yet we have experimental evidence that there is one glue that
> retains more than adequate strength under extended downhill braking, we
> may have to reconsider. One thing of which there is no doubt: your
> experience with softening glue is either wrong, dated or simply too
> limited.

Be careful about the assumptions you are making. If you read the test,
they tested these glues at a rather lower temperature than they might
encounter on a long downhill. I would not presume that that glue is any
more "adequate" than others under extended downhill braking.

I will suggest that it would have been possible to devote the kind of
research and development to tubular tires that would have resulted in a
better tire, and better glue, than was around 30 years ago. It is quite
clear to me that the tires themselves are a poor imitation of what was
available then. Since there aren't any functional silk tires from those
days any longer, I can't convince you of that, but it is true.

Since the tires are not as good, despite the claims you read here, it's
questionable that anyone has put in the R&D time to develop a better glue.
I read that report mentioned here, but remain skeptical since it sounds
too much like it was written by someone with a stake in the product.

--

David L. Johnson

__o | And what if you track down these men and kill them, what if you
_`\(,_ | killed all of us? From every corner of Europe, hundreds,
(_)/ (_) | thousands would rise up to take our places. Even Nazis can't
kill that fast. -- Paul Henreid (Casablanca).

 

[David L. Johnson]

On Wed, 02 Feb 2005 08:27:50 -0800, SocSecTrainWreck wrote:

>
> David L. Johnson wrote:
>>
>> Could be, maybe, but we had Tubasti and Clement glue back then, which
> were
>> still available, with seemingly the same properties, in the 90s.
>
> You really should go read the report:
>
> http://www.engr.ku.edu/~ktl/bicycle/Part6.pdf

Oh, I did. I am rather skeptical about it, though. For one thing, my
experience was that Wolber glue was ****. Since that does not appear in
the tests, I am skeptical. It also sure seems like this is ad copy for
Mastik One. Call me cynical, but take the results with some grain of
salt. Just because the report came from a university does not mean the
research was not sponsored by the company that makes that glue.

This engineer is wrong when he says that he waited until the glues cured.
Tubular glue does not cure, or it would not do its job properly. It has
to remain flexible and sticky; it doesn't cure, it dries to a sticky
residue.

60 degrees C is inadequate to presume the glue will hold on a downhill.
Go find a serious, winding downhill. Take it as fast as you can. Grab
the rim. Then tell me the rim is only 60 degrees.

One point they do make that I agree with. It is possible for a glue to
hold too well. If the tire separates before the glue does, then the glue
is too sticky. You may actually have to change a tire sometime (if you
don't think so, use track glue. It'll hold better, anyway). If taking
the tire off is impossible, you're in trouble.

--

David L. Johnson

__o | If all economists were laid end to end, they would not reach a
_`\(,_ | conclusion. -- George Bernard Shaw
(_)/ (_) |

 

[Tom Paterson]

From David L. Johnson:

> If the tire separates before the glue does, >then the glue is too sticky.
You may >actually have to change a tire sometime (snip)

>If taking
>the tire off is impossible, you're in trouble.

The closest I've seen to "impossible" was someone's little "20 section"
clincher ("don't get me started").

(YMMV Dept.):
I'd prefer the base tape to stay stuck on both sides while riding, especially
when riding/racing in groups, and riding on dirt/gravel roads where if you do
"pinch pop" or cut a tire causing a blowout or ERD, you want as much help as
possible staying saddle-up while slowing down enough to step off (and thanks
for no flopping tire carcass interfering with wheel turning, too).

If (IMHO, thank you) the base tape peels off the tire when replacing a flat, a)
those are fixable, b) that tire was in harm's way anyhow, and c) be glad it
didn't peel when leaned over for a recent corner.

Back in the day, on hot Texas roads, Clement Red seemed to be the best of the
few choices available, but as the test quoted here found, results with C-R
seemed inconsistent even with pretty close duplication of gluing/mounting
procedure. Ahem: thin layers of well-mixed cement that cover rim bed and
approx.central 2/3 of the base tape (one application each, preferably), wait
until dry to the touch (pref. before you touch, of course), mount, adjust with
soft pressure, then air up to 90psi or more for at least an hour or so, pref.
overnight. That drill gave minimum slop of excess cement onto braking surfaces,
etc., and at least "good" bonds, if not always the type I preferred where you
had to use a tool to get the base tape started off the rim. (Yes, I know tires
that peel off pretty easily will stay on in use, and that's OK too.)

I guess this poor old horse will learn to keep his head down someday but
meanwhile, I have a fixie project in the works that includes using some old
non-clincher race wheels (never throw anything away) and new tires. A friend
has a can of Conti "white" (brown) but maybe I'll go for some Vitt M1 so we can
compare notes, since I used up my last Clement Red tube putting on track tires
(<g> "gotta stick with what you know") five or six years ago. --TP

 

[[email protected]]

David L. Johnson wrote:
> On Wed, 02 Feb 2005 08:05:54 -0800, SocSecTrainWreck wrote:
>
> Be careful about the assumptions you are making. If you read the
test,
> they tested these glues at a rather lower temperature than they might
> encounter on a long downhill.

Maybe. Do you have any measurements about what the temperature is
likely to be? 60oC is pretty hot but it could get hotter; given the
other changes they were seeing at that temperature, like inflation
pressures, I think that you would want to be concerned if the temp got
above that, regardless of tubular or clincher tires. Another issue
could be carbon rims: with relatively poor heat conductivity they might
get considerably hotter than alloy rims under the same circumstances.

> I would not presume that that glue is any
> more "adequate" than others under extended downhill braking.

No one has to "presume" anything. The objective data is there, and
Vittoria Mastik is not more adequate, it is arguably the only one that
_is_ adequate. At the same time, I would not assert that there is no
temperature at which even it would fail; however, the bottom line is
that no one has any evidence whatsoever that it is likely to occur, and
the data presents an argument about why it is likely _not_ to occur.

> I will suggest that it would have been possible to devote the kind of
> research and development to tubular tires that would have resulted in
a
> better tire, and better glue, than was around 30 years ago. It is
quite
> clear to me that the tires themselves are a poor imitation of what
was
> available then. Since there aren't any functional silk tires from
those
> days any longer, I can't convince you of that, but it is true.

LA is known to ride on handmade Hutchinson silk tubulars. He has a very
large R&D budget by cycling team standards, so research very likely
could be continuing. Regardless, though, all the available evidence
suggests, although admittedly indirectly, that glue has improved at
some time in the last twenty five years (since FastTack was the top
choice). There is absolutely no evidence AT ALL that the best glue is
no longer in production.

> Since the tires are not as good, despite the claims you read here,

I rode tubulars both then and now, and I don't think tires are worse
now, I think that the good tires are a lot more expensive, and the
bottom of the line tires are crappier. Certainly tire rubber compound
technology has advanced, and it is equally applicable to tubulars.
Personally, I would rather be riding my Hutchinson Carbon Comp tubulars
on a twisty descent in the rain than Clement Criterium Seta Extras.

> it's
> questionable that anyone has put in the R&D time to develop a better
glue.

Tubulars have always been a relatively small market, and of course it
is relatively much smaller now than in the 80s. That does not mean that
there is no incentive for glue development. The incentive is racing,
sponsorship, and identification with cycling champions, which is what
it has always been and is what drives the high end in the bicycle
market.

> I read that report mentioned here, but remain skeptical since it
sounds
> too much like it was written by someone with a stake in the product.

Then why didn't both Vittoria products rate highly? The other Vittoria
glue tested as ****.

JP

 

[[email protected]]

David L. Johnson wrote:
> On Wed, 02 Feb 2005 08:27:50 -0800, SocSecTrainWreck wrote:
>
> >
> > David L. Johnson wrote:
> >>
> >> Could be, maybe, but we had Tubasti and Clement glue back then,
which
> > were
> >> still available, with seemingly the same properties, in the 90s.
> >
> > You really should go read the report:
> >
> > http://www.engr.ku.edu/~ktl/bicycle/Part6.pdf
>
> Oh, I did. I am rather skeptical about it, though. For one thing,
my
> experience was that Wolber glue was ****. Since that does not appear
in
> the tests, I am skeptical.

Are you sure you read the report? Wolber glue _was_ in it, and it
appeared at the bottom of the rankings, next to last, so the tests
provide objective data to support your own experience.

According to the report, "Continental and Clement supplied tires. The
Barnett Bicycle Institute, the USCF, Clement and Cycleworks of
Lawrence, Kansas supplied adhesives." If there's any bias in the report
it doesn't relate to anything I could see.

JP

 

[[email protected]]

JP writes surreptitiously:

>> Be careful about the assumptions you are making. If you read the
>> test, they tested these glues at a rather lower temperature than
>> they might encounter on a long downhill.

> Maybe. Do you have any measurements about what the temperature is
> likely to be? 60oC is pretty hot but it could get hotter; given the
> other changes they were seeing at that temperature, like inflation
> pressures, I think that you would want to be concerned if the temp
> got above that, regardless of tubular or clincher tires. Another
> issue could be carbon rims: with relatively poor heat conductivity
> they might get considerably hotter than alloy rims under the same
> circumstances.

Until I get some numeric data from planned heating tests, I'll rely on
the generation of steam audibly exiting from the valve stem hole (from
water in the hollow section rim) when braking into turns. That gives
more than 100 degrees C.

In addition, having had enough experience with variuos glues on hot
descents, I tried wooden rims that had no such problems at
all... except that the rims were non conductors so brake pads burned
off rapidly, whoch was noticable as hot materail burned my legs.
Hence, I don't believe carbon fiber rims ar a solution to that
problem.

>> I would not presume that that glue is any more "adequate" than
>> others under extended downhill braking.

> No one has to "presume" anything. The objective data is there, and
> Vittoria Mastik is not more adequate, it is arguably the only one
> that _is_ adequate. At the same time, I would not assert that there
> is no temperature at which even it would fail; however, the bottom
> line is that no one has any evidence whatsoever that it is likely to
> occur, and the data presents an argument about why it is likely
> _not_ to occur.

I'll assert that all these pressure sensitive glues fail at 0ver 100
degrees C. As I said, I tried them all and chemists weren't stupid
then. To believe that someone spent time devising such a glue for
tubular tires is not warranted by the market these tires have.

>> I will suggest that it would have been possible to devote the kind
>> of research and development to tubular tires that would have
>> resulted in a better tire, and better glue, than was around 30
>> years ago. It is quite clear to me that the tires themselves are a
>> poor imitation of what was available then. Since there aren't any
>> functional silk tires from those days any longer, I can't convince
>> you of that, but it is true.

> LA is known to ride on handmade Hutchinson silk tubulars. He has a
> very large R&D budget by cycling team standards, so research very
> likely could be continuing. Regardless, though, all the available
> evidence suggests, although admittedly indirectly, that glue has
> improved at some time in the last twenty five years (since FastTack
> was the top choice). There is absolutely no evidence AT ALL that
> the best glue is no longer in production.

Fast Tack was not the choice for performance although riders swore by
it because it had a shorter curing time than others. It did not work
any better on descents.

>> Since the tires are not as good, despite the claims you read here,

> I rode tubulars both then and now, and I don't think tires are worse
> now, I think that the good tires are a lot more expensive, and the
> bottom of the line tires are crappier. Certainly tire rubber
> compound technology has advanced, and it is equally applicable to
> tubulars. Personally, I would rather be riding my Hutchinson Carbon
> Comp tubulars on a twisty descent in the rain than Clement Criterium
> Seta Extras.

You can make such statements in the absence of comparative tests but
having used and repaired tubulars over the years and even recently, I
do not agree with your assessment. I find the quality of manufacture
and the wear durability poorer.

>> It' questionable that anyone has put in the R&D time to develop a
>> better glue.

> Tubulars have always been a relatively small market, and of course
> it is relatively much smaller now than in the 80s. That does not
> mean that there is no incentive for glue development. The incentive
> is racing, sponsorship, and identification with cycling champions,
> which is what it has always been and is what drives the high end in
> the bicycle market.

The incentive is money as in other businesses. THis is not a charity
affair.

>> I read that report mentioned here, but remain skeptical since it
>> sounds too much like it was written by someone with a stake in the
>> product.

> Then why didn't both Vittoria products rate highly? The other
> Vittoria glue tested as ****.

That may be but I find the report not credible and not done in a
scientific method that is yet to be explained. What I would believe
is a standard smooth surface and test strip showing peel strength from
low to high temperature in the range that one expects to see in
bicycle use. That would need to span at least from 0 to 100 degrees
C. Bar graphs, no matter how wide the bars, are not a reasonable
diagnostic for such a test.

Continuity of data is in itself reassuring and reveals much more than
a single number. The bar graph is only a smoke screen for lack of data.

You can compare that with RR data taken by reliable sources:

http://www.sheldonbrown.com/brandt/rolling-resistance-tubular.html

Jobst Brandt
[email protected]

 

[[email protected]]

JP writes surreptitiously:

>> Be careful about the assumptions you are making. If you read the
>> test, they tested these glues at a rather lower temperature than
>> they might encounter on a long downhill.

> Maybe. Do you have any measurements about what the temperature is
> likely to be? 60oC is pretty hot but it could get hotter; given the
> other changes they were seeing at that temperature, like inflation
> pressures, I think that you would want to be concerned if the temp
> got above that, regardless of tubular or clincher tires. Another
> issue could be carbon rims: with relatively poor heat conductivity
> they might get considerably hotter than alloy rims under the same
> circumstances.

Until I get some numeric data from planned heating tests, I'll rely on
the generation of steam audibly exiting from the valve stem hole (from
water in the hollow section rim) when braking into turns. That gives
more than 100 degrees C.

In addition, having had enough experience with various glues on hot
descents, I tried wooden rims that had no such problems at all...
except that wood rims are non conductors so brake pads burned off
rapidly, which I noticed as hot material burned my legs. Hence, I
don't believe carbon fiber rims are a solution to the heating problem.

>> I would not presume that that glue is any more "adequate" than
>> others under extended downhill braking.

> No one has to "presume" anything. The objective data is there, and
> Vittoria Mastik is not more adequate, it is arguably the only one
> that _is_ adequate. At the same time, I would not assert that there
> is no temperature at which even it would fail; however, the bottom
> line is that no one has any evidence whatsoever that it is likely to
> occur, and the data presents an argument about why it is likely
> _not_ to occur.

I'll assert that all these pressure sensitive glues fail at over 100
degrees C. As I said, I tried Clement, Vittoria, Continental,
Pastali, Tubasti and various rim tapes. I don't believe chemists
were ignorant then or any smarter today. To believe that someone
spent time devising such a glue for tubular tires more recently is not
warranted by the current market.

>> I will suggest that it would have been possible to devote the kind
>> of research and development to tubular tires that would have
>> resulted in a better tire, and better glue, than was around 30
>> years ago. It is quite clear to me that the tires themselves are a
>> poor imitation of what was available then. Since there aren't any
>> functional silk tires from those days any longer, I can't convince
>> you of that, but it is true.

> LA is known to ride on handmade Hutchinson silk tubulars. He has a
> very large R&D budget by cycling team standards, so research very
> likely could be continuing. Regardless, though, all the available
> evidence suggests, although admittedly indirectly, that glue has
> improved at some time in the last twenty five years (since FastTack
> was the top choice). There is absolutely no evidence AT ALL that
> the best glue is no longer in production.

Fast Tack was not the choice for performance although riders swore by
it because it had a shorter curing time than others. It did not work
any better on descents and didn't work well when changing tires.

>> Since the tires are not as good, despite the claims you read here,

> I rode tubulars both then and now, and I don't think tires are worse
> now, I think that the good tires are a lot more expensive, and the
> bottom of the line tires are crappier. Certainly tire rubber
> compound technology has advanced, and it is equally applicable to
> tubulars. Personally, I would rather be riding my Hutchinson Carbon
> Comp tubulars on a twisty descent in the rain than Clement Criterium
> Seta Extras.

You can make such statements in the absence of comparative tests but
having used and repaired tubulars over the years and even recently, I
do not agree with your assessment. I find the quality of manufacture
and the wear durability poorer.

>> It' questionable that anyone has put in the R&D time to develop a
>> better glue.

> Tubulars have always been a relatively small market, and of course
> it is relatively much smaller now than in the 80s. That does not
> mean that there is no incentive for glue development. The incentive
> is racing, sponsorship, and identification with cycling champions,
> which is what it has always been and is what drives the high end in
> the bicycle market.

The incentive is money as in other businesses. This is not a charity
affair.

>> I read that report mentioned here, but remain skeptical since it
>> sounds too much like it was written by someone with a stake in the
>> product.

> Then why didn't both Vittoria products rate highly? The other
> Vittoria glue tested as ****.

That may be but I find the report not credible and not done in a
scientific method that is yet to be explained. What I would believe
is a standard smooth surface and test strip showing peel strength from
low to high temperature in the range that one expects to see in
bicycle use. That would need to span at least from 0 to 100 degrees
C. Bar graphs, no matter how wide the bars, are not a reasonable
diagnostic for such a test.

Continuity of data is in itself reassuring and reveals much more than
a single number. The bar graph is only a smoke screen for lack of data.

You can compare that with RR data taken by reliable sources:

http://www.sheldonbrown.com/brandt/rolling-resistance-tubular.html

Jobst Brandt
[email protected]

 

[David L. Johnson]

On Fri, 04 Feb 2005 13:01:00 -0800, SocSecTrainWreck wrote:

>> I read that report mentioned here, but remain skeptical since it
> sounds
>> too much like it was written by someone with a stake in the product.
>
> Then why didn't both Vittoria products rate highly? The other Vittoria
> glue tested as ****.

Maybe they were just promoting this particular product, or aware of the
fact that most people thought the old glue was **** as well.

What I meant by the report sounding like marketing was, for example, the
fact that all the comparisons were in deci-Vittorias. This one glue was
the standard for measurement of all the others. Nothing else was
indicated on the scale except what percentage of the Vittoria
Mastic-one glue the others achieved. No indication of what that scale
really was, or even whether it was linear with respect to energy applied.
Those graphs had no more intrinsic meaning than the 0-60 graphs on a car
ad, showing the car they are advertising clearly out-performing everyone
else.

--

David L. Johnson

__o | Do not worry about your difficulties in mathematics, I can
_`\(,_ | assure you that mine are all greater. -- A. Einstein
(_)/ (_) |

 

[David L. Johnson]

On Fri, 04 Feb 2005 14:17:58 -0800, SocSecTrainWreck wrote:

> Are you sure you read the report? Wolber glue _was_ in it, and it
> appeared at the bottom of the rankings, next to last, so the tests
> provide objective data to support your own experience.

Wolber was in the middle of the pack on the first graph, of "adhesive
performance", being 55% of the "standard", which was
the Vittoria. It was third in "adhesive performance comparison in gluing
procedures", whatever that means. The part 5 table did put it last, but
that is not consistent with the other graphs.

>
> According to the report, "Continental and Clement supplied tires. The
> Barnett Bicycle Institute, the USCF, Clement and Cycleworks of Lawrence,
> Kansas supplied adhesives." If there's any bias in the report it doesn't
> relate to anything I could see.

Yeah, it doesn't. But that does not convince me.

--

David L. Johnson

__o | When you are up to your ass in alligators, it's hard to remember
_`\(,_ | that your initial objective was to drain the swamp. -- LBJ
(_)/ (_) |

 

[A Muzi]

[email protected] wrote:
-snip-
>>>You really should go read the report:
>>>http://www.engr.ku.edu/~ktl/bicycle/Part6.pdf

> David L. Johnson wrote:
-snip-
>>Oh, I did. I am rather skeptical about it, though. For one thing,
> my
>>experience was that Wolber glue was ****. Since that does not appear
> in the tests, I am skeptical.

[email protected] wrote:
> Are you sure you read the report? Wolber glue _was_ in it, and it
> appeared at the bottom of the rankings, next to last, so the tests
> provide objective data to support your own experience.
>
> According to the report, "Continental and Clement supplied tires. The
> Barnett Bicycle Institute, the USCF, Clement and Cycleworks of
> Lawrence, Kansas supplied adhesives." If there's any bias in the report
> it doesn't relate to anything I could see.

Except that Clement _is_ Vittoria.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971