Tubular rim glue ???
Trackie
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 Yanky 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.
Thanks in advance
Trackie, or more commonly "The Old one"
Steven L. Sheffield
<r...@net.nz> wrote:
>
> 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 Yanky 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.
What brand of tubbies are you using?
--
Steven L. Sheffield
stevens at veloworks dot com
veloworks at worldnet dot ay tea tee dot net
bellum pax est libertas servitus est ignoratio vis est
ess ay ell tea ell ay kay ee sea aye tee why you ti ay aitch
aitch tee tea pea colon [for word] slash [four ward] slash double-you
double-yew double-ewe dot veloworks dot com [four word] slash
Qui si parla Campagnolo
Either Continental or Vittoria, both are specific to tubies and work well.
Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
Calvin Jones
The gluing procedures and techniques are typically as critical, if not
more critcal, than the brand of glue. (There are, however, some very
pour brands as well.)
For gluing procedure see:
http://www.parktool.com/repair_help/tubular.shtml
John Everett
>
>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 Yanky 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
jeverett3<AT>earthlink<DOT>net http://home.earthlink.net/~jeverett3
David L. Johnson
>
> 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)
Any tubular glue would be plenty strong enough, if applied properly and if
the tires are decent. I think blaming the glue for your friend's accident
deflects attention from the real issue -- it's the "too little" part that
is a problem.
I have used Tubasti, Clement, and Fas-Tac (automotive trim adhesive). All
worked fine except on one brand of tire (Wolber) whose base tape came
loose due to, I was told, incompatibility between the glue they used and
the rim cement I was using. Since I never had any trouble with any other
tire that way, I tend to think there that the fault was with Wolber.
If you want seriously well-glued tires; put a layer on the tire, and a
layer on the rim. Let dry, then put the tire on the rim. I have had to
use tools to remove tires glued on that way. Impossible to cause trouble
on the track. On the road, though, any glue can be overheated in a
serious downhill with lots of braking.
For the track, you can also use shellac. Much harder glue, less rolling
resistance. PITA to fix a flat.
--
David L. Johnson
__o | Arguing with an engineer is like mud wrestling with a pig... You
_`\(,_ | soon find out the pig likes it!
(_)/ (_) |
Ted B
well. No more glue!
--
daveornee
Great article John! This article is very detailed and helpful. Quality
information like this helps tubular riders ride with maximum safety
and security.
--
John Dacey
si potentior, tibi." - Seneca
>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.
It seems particularly cruel to blame the victim whenever someone
suffers more than a little road rash, but if a crash is initiated by a
rolled tire, it generally has to be regarded as a self-inflicted
wound. Although some rim adhesives can be better than others, failure
to follow proper gluing technique is far and away the most likely
culprit when rims and tires go their separate ways.
>As I have a Yanky 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.
Because the adhesive securing track tires won't generally have to
suffer the thermal problems associated with rims superheated from
brake pad friction and track racing rarely happens in the rain,
arguably the selection of a glue for track use is less critical than
for road racing. Even so, I have rather less confidence in some brands
than others. I believe that Vittoria Mastik One, Continental and Soyo
rim cements are all solid choices. An automotive trim adhesive from 3M
("Fast Tack") is also popular among track racers, notable for its fast
cure time compared to dedicated rim cement.
-------------------------------
John Dacey
Business Cycles, Miami, Florida
Now in our twenty-first year.
Our catalogue of track equipment: eighth year online.
http://www.businesscycles.com
Mike S.
"Qui si parla Campagnolo " <vecc...@aol.com> wrote in message
news:20040227085701...@mb-m11.aol.com...
> ro-<< What is a good brand of tubular glue in America? >><BR><BR>
>
> Either Continental or Vittoria, both are specific to tubies and work well.
>
brush!
Mike
John Dacey
"Omne ignotum pro magnifico est." - Tacitus
>For the track, you can also use shellac. Much harder glue, less rolling
>resistance.
These claims for lowered rolling resistance recur here sporadically,
but they never seem to include supporting documentation to quantify
them.
Isn't it time we learned whether we're talking about picoseconds per
kilometer or if glue selection for track racers really merits more
consideration than it currently receives?
jobst....@stanfordalumni.org
>> For the track, you can also use shellac. Much harder glue, less
>> rolling resistance.
> These claims for lowered rolling resistance recur here sporadically,
> but they never seem to include supporting documentation to quantify
> them.
You can see the difference on the graphs that have been explained
often here. The tubulars that have the best RR by their nature
(flattest curve) lie higher than clinchers due to glue squirm. That
this is the case should be obvious when inspecting rims that have been
ridden a lot. They have base tape wear marks and the glue is full of
grey aluminum wear dust.
http://www.terrymorse.com/bike/imgs/rolres.gif
> Isn't it time we learned whether we're talking about picoseconds per
> kilometer or if glue selection for track racers really merits more
> consideration than it currently receives?
It is significant enough that the ancients in the days of tubulars
invented hard glue to get rid of this parasitic loss for record events
on the track. It took me a few seconds to recognize this on seeing
the curves in these rolling resistance tests. Besides, around here
riders often wore through the base tape from all the creep on road
glue from Pirelli, Clement, D'Allesandro' Tubasti, Pastali, etc.
I was grateful to the Specialized Touring-II tire that absolved me of
messing with tubulars. Those FAQ items on manufacture, repair and
gluing of tubulars did not come from empirical thinking. That was a
lot of impractical tire repair... a pain in the ass.
Jobst Brandt
jobst....@stanfordalumni.org
David L. Johnson
>>For the track, you can also use shellac. Much harder glue, less rolling
>>resistance.
>
> These claims for lowered rolling resistance recur here sporadically,
> but they never seem to include supporting documentation to quantify
> them.
>
> Isn't it time we learned whether we're talking about picoseconds per
> kilometer or if glue selection for track racers really merits more
> consideration than it currently receives?
I don't have the data, but Jobst often points out tests that show that
road tubulars have more rolling resistance than clinchers, which he
ascribes to flex of the glue. That was well beyond the
picosecond/kilometer range, but how far beyond I don't recall.
The _assumption_ is that the hard shellac will return a track tubular to
rolling resistance numbers more like a clincher --- begging the question
about using clinchers instead.
--
David L. Johnson
__o | If all economists were laid end to end, they would not reach a
_`\(,_ | conclusion. -- George Bernard Shaw
(_)/ (_) |
Mike S.
<jobst....@stanfordalumni.org> wrote in message
news:NzS%b.4299$_3.6...@typhoon.sonic.net...
> John Dacey writes:
>
> >> For the track, you can also use shellac. Much harder glue, less
> >> rolling resistance.
>
> > These claims for lowered rolling resistance recur here sporadically,
> > but they never seem to include supporting documentation to quantify
> > them.
>
> You can see the difference on the graphs that have been explained
> often here. The tubulars that have the best RR by their nature
> (flattest curve) lie higher than clinchers due to glue squirm. That
> this is the case should be obvious when inspecting rims that have been
> ridden a lot. They have base tape wear marks and the glue is full of
> grey aluminum wear dust.
>
> http://www.terrymorse.com/bike/imgs/rolres.gif
>
Dude, that chart is WAY out of date! We're talking about Michelin
Supercomps and other tires that haven't been made for YEARS.
I'd be interested to see a new chart with some updated tires... Anyone
else?
For example: where do my Tufos stand? How bout the Michelin HiLite Prestige
tires I train on? Or the Hutchison Carbon Comps? Or...?
Mike
tr...@notarealaddr.com
>> but they never seem to include supporting documentation to quantify
>> them.
That's because there is not supporting documentation outside of Jobst
Brandt's imagination. rec.bicycles.tech readers will recognize JB's
posts in most every thread despite no actual experience as a bicycle
mechanic or component designer outside of the Avocet cyclometer.
>It is significant enough that the ancients in the days of tubulars
>invented hard glue to get rid of this parasitic loss for record events
>on the track.
The use of ad hominem, "the ancients" is a Jobst signature, crudely
inserted to divert attention from the actual issues. In fact there is
no such rolling resistance due to tubular glues of any kind.
Problem is Jobst's data is based on a machine of his design for
illustrating performance advantages of the tires of his employer
(Avocet). It in no way simulates actual riding conditions. It should
also be pointed out that the slick, high-pressure Avocet clinchers
that showed such high performance in Jobst's "tests" are no available.
Too many real world cyclists lost traction in real world conditions
and suffered many square yards of road rash as a result. Take note,
and heed, if you should be so foolish as to take Jobst's advice on any
subject related to bicycles.
Tommy Roster
carlfogel
Dear Tommy,
If you go to the site suggested by the address of the graph link, you'll
find what looks like extensive data:
http://www.terrymorse.com/bike/rrdiscuss.htm
As for the possible disappearance of the tires from the market, are tire
models from the 1986 testing still available 18 years later?
To use Chalo Colina's immortal phrase, I doubt that I'll be "pasting my
own tires on with frog snot anytime soon," but it seems reasonable that
an extremely thin, hard layer of frog snot would contribute less to
rolling resistance than a thick, soft layer of amphibian mucous.
Which lane would you rather race in, one covered with a thin layer of
hard stuff or one with a thin layer of soft stuff?
Carl Fogel
--
jobst....@stanfordalumni.org
>>> These claims for lowered rolling resistance recur here
>>> sporadically, but they never seem to include supporting
>>> documentation to quantify them.
> That's because there is not supporting documentation outside of
> Jobst Brandt's imagination. rec.bicycles.tech readers will
> recognize JB's posts in most every thread despite no actual
> experience as a bicycle mechanic or component designer outside of
> the Avocet cyclometer.
I take it you are more impressed by people who post unsupported claims
while citing their educational titles while using scientific jargon to
give credibility to their claims. As Richard Feynman said "If you
can't explain it in plain English, you probably don't understand it
yourself." I suggest you respond to the statements I made rather than
use insults to put forth your point of view.
>> It is significant enough that the ancients in the days of tubulars
>> invented hard glue to get rid of this parasitic loss for record
>> events on the track.
> The use of ad hominem, "the ancients" is a Jobst signature, crudely
> inserted to divert attention from the actual issues. In fact there
> is no such rolling resistance due to tubular glues of any kind.
Oh! "the ancients" refers to those professionals who long ago
developed high performance tubulars and their use. To whom do you
believe this was an ad hominem? I use the term often to refer to
those who came before my time and made significant contributions to
the art. How do you explain the existence of road and track glue? To
what do you attribute the data in those curves and how do you explain
wear on base tapes that leaves cloth abrasion marks in aluminum rims.
I'm interested on what you base your claim that pressure sensitive rim
glue has no losses. Have you ridden tubulars over any significant
distance?
> Problem is Jobst's data is based on a machine of his design for
> illustrating performance advantages of the tires of his employer
> (Avocet).
These tests were done in Japan by IRC tire company on a standard RR
machine that is used to compare tires. Since RR is caused by tire
flex, measuring all tires against a steel drum is a valid comparison
that favors no specific tire. Motor vehicle tire RR is tested on such
machines.
> It in no way simulates actual riding conditions. It should
> also be pointed out that the slick, high-pressure Avocet clinchers
> that showed such high performance in Jobst's "tests" are no available.
I think you'll find them in various bicycle shops and that people who
read this newsgroup have had good service from them. What is it you
feel is missing in the rolling resistance test that makes the
comparisons invalid? How do you propose they be done? You'll find
that Michelin and Continental use the same test method for their
evaluations. Michelin even brought such a machine to the InterBike
trade show in 2002 for anyone to use.
> Too many real world cyclists lost traction in real world conditions
> and suffered many square yards of road rash as a result.
Let's see some evidence of this. Meanwhile evidence to the contrary
abounds.
> Take note, and heed, if you should be so foolish as to take Jobst's
> advice on any subject related to bicycles.
I'm curious what it is that makes you so venomous.
Jobst Brandt
jobst....@stanfordalumni.org
JP
> Which lane would you rather race in, one covered with a thin layer of
> hard stuff or one with a thin layer of soft stuff?
I would rather race on which ever is better. Soft stuff versus hard
stuff could also be described as supple stuff versus brittle stuff.
A few questions come to mind: How well were the tires glued on when
they were tested and were they glued on by a Clement technician or
Avocet? Also, has anyone proven that the advantages of tubulars do not
more than make up for supposed difference in rolling resistance? For
example, despite all the discussion on the subject, I have yet to see
any evidence that rotaional inertia, and therefore the weight of tires
and rims, can be dismissed as insignificant. Or, in real world
conditions does the equation change somehow because clinchers require
higher relative pressures? Does the softer ride of tubulars save
enough energy of the rider (since vibrating muscles are known as a
cause of fatigue) to offset an admittedly very small at most
difference in rolling resistance?
I don't know, and neither does anyone else. It seems clear that
tubulars at one time held a performance advantage. What is not clear
is whether the advantage has slipped due to improvements in clinchers
or as a result of paying pros big bucks to use them, with trickle down
acceptance. As a consultant to Avocet, one of the early proponents of
high performance clincher tires, Jobst is someone worth listening to,
but should be treated with healthy scepticism.
JP
John Dacey
wrote:
>John Dacey writes:
>> These claims for lowered rolling resistance recur here sporadically,
>> but they never seem to include supporting documentation to quantify
>> them.
>
>You can see the difference on the graphs that have been explained
>often here. The tubulars that have the best RR by their nature
>(flattest curve) lie higher than clinchers due to glue squirm. That
>this is the case should be obvious when inspecting rims that have been
>ridden a lot. They have base tape wear marks and the glue is full of
>grey aluminum wear dust.
>
>http://www.terrymorse.com/bike/imgs/rolres.gif
You say I can see the difference, but I don't. There's no mention of
the kind of adhesive used for the two tubular models in the results
you cite. Where does the plot lie for tires with a hard cement?
>
>> Isn't it time we learned whether we're talking about picoseconds per
>> kilometer or if glue selection for track racers really merits more
>> consideration than it currently receives?
>
>It is significant enough that the ancients in the days of tubulars
>invented hard glue to get rid of this parasitic loss for record events
>on the track. It took me a few seconds to recognize this on seeing
>the curves in these rolling resistance tests. Besides, around here
>riders often wore through the base tape from all the creep on road
>glue from Pirelli, Clement, D'Allesandro' Tubasti, Pastali, etc.
It seems to me that your "recognition" of this is conjecture, inasmuch
as the tubular results with hard glue aren't actually included on the
graph. Also, from the recitation of the brands of cements on which
your comments are derived, it's clear that you're opinions are based
upon products of 25 years ago and perhaps not consistent with results
that might be had from contemporary tire adhesives from Continental,
Vittoria, Soyo and 3M. The "squirminess" of Tubasti is probably much
greater than for Mastik One.
The Ancients, whom you credit with inventing hard glue for select
track events are the same ones who began the custom of inflating those
tires to very high pressures; yet you've regularly described high
pressure as gratuitous excess. High (10+ BAR) pressure for track
tubulars remains a common practice, while using shellac and
track-specific tubular cement is rarely (if ever) still done. Why
would one bit of ancient wisdom that you say is significant (hard
glue) fall from use while another that you regard as needless risk
(high pressure) remain common practice unless people found rewards
with the one and none in the other?
>
>I was grateful to the Specialized Touring-II tire that absolved me of
>messing with tubulars. Those FAQ items on manufacture, repair and
>gluing of tubulars did not come from empirical thinking. That was a
>lot of impractical tire repair... a pain in the ass.
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?
-------------------------------
John Dacey
Business Cycles, Miami, Florida
Now in our twenty-first year.
Our catalog of track equipment: eighth year online
-------------------------------
Mike S.
"JP" <SocSecTr...@earthlink.net> wrote in message
news:1f323b67.04022...@posting.google.com...
Holy Cow! Skepticism of the "fount of all cycling-related knowledge?"
Blasphemer!
While I admit that Jobst knows a bunch more than I do, he's not
all-knowledgeable.
I reserve the right to think for myself rather than parrot what I've been
told.
Mike
Werehatrack
said:
>>> These claims for lowered rolling resistance recur here sporadically,
>>> but they never seem to include supporting documentation to quantify
>>> them.
>
>That's because there is not supporting documentation outside of Jobst
>Brandt's imagination. rec.bicycles.tech readers will recognize JB's
>posts in most every thread despite no actual experience as a bicycle
>mechanic or component designer outside of the Avocet cyclometer.
Well, that little rant deserves just one terse response.
Plonk.
--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.
carlfogel
> On Sat, 28 Feb 2004 01:57:01 GMT, jobst....@stanfordalumni.org wrote:
> >John Dacey writes:
> >> These claims for lowered rolling resistance recur here
> >> sporadically, but they never seem to include supporting
> >> documentation to quantify them.
> >
> >You can see the difference on the graphs that have been explained often
> >here. The tubulars that have the best RR by their nature (flattest
> >curve) lie higher than clinchers due to glue squirm. That this is the
> >case should be obvious when inspecting rims that have been ridden a
> >lot. They have base tape wear marks and the glue is full of grey
> >aluminum wear dust.
> >
> twenty-first year. Our catalog of track equipment: eighth year online
> -------------------------------
Dear John,
Nicely done.
I'm sorry that I wandered off and lost sight of your question. If no
one has done tests to compare the losses for the different kinds of
glue and shellac, then we're all chattering in bad theoretical light,
if not the dark.
The lack of specific data addressing our questions may explain why so
many of our threads descend into yes-it-is, no-it-isn't arguments.
I predict that hard shellac should roll with less loss than soft
glue, but I'm absolutely certain that neither glue nor shellac care
what I predict.
Speaking of specific data, does anyone have a handy link to tests of
rolling resistance versus inflation for modern tires?
Carl Fogel
P.S. Do you know whether Japanese keirin racers glue their tires on? If
so, with what?
C.F.
--
jobst....@stanfordalumni.org
http://www.terrymorse.com/bike/imgs/rolres.gif
Your complaints strike me as so much deja-vu. Just because these
matters are not understood in bicycling today does not mean they
weren't and aren't as I describe. This was the attack I received
these past 20+ years about "the Bicycle Wheel", attacks that were, as
yours, based on what was commonly believed.
When I began racing there were no high performance clinchers or
clincher rims. With tubular tires, the first thing that came to my
attention was that there were two kinds of glue, road and track. No
one could tell me why and the reasons given were so incredible,
although solidly embedded in common knowledge, that no one questioned
that track riders have a greater tendency to roll tires and must
therefore use harder glue.
This is patently untrue. Road riders rolled tires far more often than
track riders, most of whom used road glue on their track wheels.
Besides, road glue was susceptible to melting on descents so that the
only thing holding the tire in place was the clinch caused by
inflation pressure (formula for this in "the Bicycle Wheel") and the
valve stem that kept the tire from sliding around the rim.
> The Ancients, whom you credit with inventing hard glue for select
> track events are the same ones who began the custom of inflating
> those tires to very high pressures; yet you've regularly described
> high pressure as gratuitous excess. High (10+ BAR) pressure for
> track tubulars remains a common practice, while using shellac and
> track-specific tubular cement is rarely (if ever) still done. Why
> would one bit of ancient wisdom that you say is significant (hard
> glue) fall from use while another that you regard as needless risk
> (high pressure) remain common practice unless people found rewards
> with the one and none in the other?
Well? If you looked at the curves carefully, you will see that these
are a family of curves, their curvature being dependent on their
casing losses that reduce with increased inflation pressure. That the
tubulars are shifted upward shows how large the glue losses are.
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.
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.
>> I was grateful to the Specialized Touring-II tire that absolved me
>> of messing with tubulars. Those FAQ items on manufacture, repair
>> and gluing of tubulars did not come from empirical thinking. That
>> was a lot of impractical tire repair... a pain in the ass.
> 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?
You have the values on the graphs. Why don't you tell me what
difference it makes. I don't know what the other losses are for your
rider and bicycle. I know that if I were a contender and trying to
set a pursuit record, I would use hard glue or clinchers and those
clinchers would have minimal tread rubber. The Tipo-00 clement silks
used thin latex inner tubes and tread because carbon black increases
hysteretic losses in rubber. Latex has the best coefficient of
restitution of available rubbers.
By the way, you could probably find this response through Google for
previous years. It hasn't changed. Only the attacks have become more
personal and accusatory.
Jobst Brandt
jobst....@stanfordalumni.org
Werehatrack
trollish traffic.
Carl Fogel
Dear Jobst,
Wouldn't it have been shorter and simpler to reply
that no, you can't answer John's specific question?
I can't answer it, either, but he isn't attacking or
accusing either of us personally.
As has been said, your tone makes enemies of those
who agree with you.
Carl Fogel
Mike S.
<snip>
> Dear Jobst,
>
> Wouldn't it have been shorter and simpler to reply
> that no, you can't answer John's specific question?
>
> I can't answer it, either, but he isn't attacking or
> accusing either of us personally.
>
> As has been said, your tone makes enemies of those
> who agree with you.
>
> Carl Fogel
While I don't always agree with what JB says, for the most part, I find that
he does in fact know his stuff. In general, I don't particularly care for
the way his answers come across.
Having said that, where's the data for tires made in the last 20 years?
Why can't anyone answer John's question(s)?
Mike
John Dacey
wrote:
I’m not attacking you. Yes, we’ve been here before - the last time a
few weeks ago; but the website hosting the rolling resistance graphic
was not working then, so without that reference at hand I let the
matter drop. Over time, you’ve gotten quite a lot of mileage out of
your claims for rediscovering the importance of hard glue. I’ve simply
sought to quantify how much the track community has been missing by
being cavalier about its use of rim cements.
>
>When I began racing there were no high performance clinchers or
>clincher rims. With tubular tires, the first thing that came to my
>attention was that there were two kinds of glue, road and track. No
>one could tell me why and the reasons given were so incredible,
>although solidly embedded in common knowledge, that no one questioned
>that track riders have a greater tendency to roll tires and must
>therefore use harder glue.
>
>This is patently untrue. Road riders rolled tires far more often than
>track riders, most of whom used road glue on their track wheels.
>Besides, road glue was susceptible to melting on descents so that the
>only thing holding the tire in place was the clinch caused by
>inflation pressure (formula for this in "the Bicycle Wheel") and the
>valve stem that kept the tire from sliding around the rim.
I am in basic agreement with the above and have written so in this
thread in my reply to the original poster.
>
>> The Ancients, whom you credit with inventing hard glue for select
>> track events are the same ones who began the custom of inflating
>> those tires to very high pressures; yet you've regularly described
>> high pressure as gratuitous excess. High (10+ BAR) pressure for
>> track tubulars remains a common practice, while using shellac and
>> track-specific tubular cement is rarely (if ever) still done. Why
>> would one bit of ancient wisdom that you say is significant (hard
>> glue) fall from use while another that you regard as needless risk
>> (high pressure) remain common practice unless people found rewards
>> with the one and none in the other?
>
>Well? If you looked at the curves carefully, you will see that these
>are a family of curves, their curvature being dependent on their
>casing losses that reduce with increased inflation pressure. That the
>tubulars are shifted upward shows how large the glue losses are.
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?
>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.
>
>>> I was grateful to the Specialized Touring-II tire that absolved me
>>> of messing with tubulars. Those FAQ items on manufacture, repair
>>> and gluing of tubulars did not come from empirical thinking. That
>>> was a lot of impractical tire repair... a pain in the ass.
>
>> 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?
>
>You have the values on the graphs. Why don't you tell me what
>difference it makes.
If I could solve for X, I wouldn't have dirty fingernails every day. I
read this group in the hope that from time to time there's a kernel of
useful information that falls from the plates of professionals with
real expertise in these matters.
>I don't know what the other losses are for your
>rider and bicycle.
Don't overcomplicate things -- I just want to isolate how much the
choice of glue matters. Assume a 180 lb package of bike and rider that
can knock out flying kilos @ 50kph with metronomic consistency without
ever fatiguing.
> I know that if I were a contender and trying to
>set a pursuit record, I would use hard glue or clinchers and those
>clinchers would have minimal tread rubber. The Tipo-00 clement silks
>used thin latex inner tubes and tread because carbon black increases
>hysteretic losses in rubber. Latex has the best coefficient of
>restitution of available rubbers.
You've pretty much described the Andre Dugast tubulars whose bright
pink latex treads are so conspicuous in many pix from elite track
championships in recent years.
>
>By the way, you could probably find this response through Google for
>previous years. It hasn't changed. Only the attacks have become more
>personal and accusatory.
No, it hasn't changed but I remain hopeful that someday more details
will come forth. Now that I know that your comments about the
importance of the choice of cement comes from deduction rather than
actual measurement though, I guess I'll stop asking.
jobst....@stanfordalumni.org
>> Well. If you looked at the curves carefully, you will see that
>> these are a family of curves, their curvature being dependent on
>> their casing losses that reduce with increased inflation pressure.
>> That the tubulars are shifted upward shows how large the glue
>> losses are.
> 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 believe in magic and don't believe much of what bicycle
manufacturers claim to be better if it shows the slightest
contradiction. Therefore, since energy cannot be spirited away and we
know that the tubular tire is lighter, thinner and has less tread and
tube, the obvious result is that the out of character RR losses must
be glue. When we got these curves and data from IRC, it struck all
who saw them that the two tubulars were way out of character. Having
much experiences with tubulars at that time my mentioning that it was
rim glue made the others say "why didn't I think of that?"
Today that is less obvious, so few people riding tubulars for all
their bicycling.
Jobst Brandt
jobst....@stanfordalumni.org
John Dacey
>P.S. Do you know whether Japanese keirin racers glue their tires on? If
> so, with what?
Insofar as I know, only tubular tires are used in professional keirin
racing. I understand that a set of tires is issued to the racer prior
to the beginning of each race meet by the organizing body (the tires
may have been used before by another racer) and it is the
responsibility of the racer to properly adhere the tires to his
wheels. I don't know if there is a list of approved rim cements that
must be used, but I suspect that this would be the case. One brand is
"Soyo", there may be others - I dunno.
-------------------------------
John Dacey
Business Cycles, Miami, Florida
Mike S.
"John Dacey" <jda...@businesscycles.com> wrote in message
news:8qj54015u5c5jh3ua...@4ax.com...
> "In velo, veritas." - Pseudolus
> On Sun, 29 Feb 2004 20:51:06 GMT, carlfogel
> <usenet...@cyclingforums.com> wrote:
>
>
> >P.S. Do you know whether Japanese keirin racers glue their tires on? If
> > so, with what?
>
> Insofar as I know, only tubular tires are used in professional keirin
> racing. I understand that a set of tires is issued to the racer prior
> to the beginning of each race meet by the organizing body (the tires
> may have been used before by another racer) and it is the
> responsibility of the racer to properly adhere the tires to his
> wheels. I don't know if there is a list of approved rim cements that
> must be used, but I suspect that this would be the case. One brand is
> "Soyo", there may be others - I dunno.
>
Everything else is regulated. I'd bet that the glue is too. I've never
seen any glue with NJS on it, but then, I ride Euro glues.
Mike
tr...@notarealaddr.com
>Speaking of specific data, does anyone have a handy link to tests of
>rolling resistance versus inflation for modern tires?
Apparently not. I suspect because it is nowhere near the most important
factor in tire performance. If you want low rolling resistance there are
several options: use smaller tires, higher pressure, a stiffer casing,
harder tread compound... All of these are reasons why any given tire
might show variations both in comparison to other identical tires and
to different types of tires.
The problem with a simple measurement like roling resistance is it is just
one of many factors in *real-world* tire performance. Another problem
is that low rolling resistance negatively correlates with traction.
In a straight line, on a smooth clean road, lower rolling resistance =
better performance. As soon as you introduce imperfect pavement or
turns rolling resistance = worse performance.
This is part of why a small rotating steel drum is no measure of tire
performance and why hypothesizes regarding the effect of tubular glue
on rolling resistance have gone unsubstantiated. This is not why Jobst
continues to make such claims as if they were facts but that's another
story.
Tommy Roster
jobst....@stanfordalumni.org
>> Speaking of specific data, does anyone have a handy link to tests
>> of rolling resistance versus inflation for modern tires?
> Apparently not. I suspect because it is nowhere near the most
> important factor in tire performance. If you want low rolling
> resistance there are several options: use smaller tires, higher
> pressure, a stiffer casing, harder tread compound... All of these
> are reasons why any given tire might show variations both in
> comparison to other identical tires and to different types of tires.
Not so. The items you list other than higher inflation pressure only
cause higher rolling losses. As has been mentioned here often, the
more easily the tire, casing tube and tread bend, the less loss. That
is why record attempts are made with silk tires with condom like tubes
and tread, latex having less hysteretic losses than synthetic rubber.
You could get lower RR with larger cross section tires if you could
get them with thin casings and thin tread rubber. The selection of
tube is also open but latex would be the lowest loss. The reason this
is not done is that durability is poor and air loss high. Those who
haven't had the opportunity to ride on high performance tubulars are
not aware how soon pumping tires becomes tedious after a short while.
Typical Clement tubulars required daily inflation.
> The problem with a simple measurement like rolling resistance is it
> is just one of many factors in *real-world* tire performance.
> Another problem is that low rolling resistance negatively correlates
> with traction. In a straight line, on a smooth clean road, lower
> rolling resistance = better performance. As soon as you introduce
> imperfect pavement or turns rolling resistance = worse performance.
Can you explain what you mean by this. I take it you are saying that
tires that have better rolling properties than others on a smooth
surface somehow have poorer performance than others on rougher
surfaces. How does this occur?
> This is part of why a small rotating steel drum is no measure of
> tire performance and why hypothesizes regarding the effect of
> tubular glue on rolling resistance have gone unsubstantiated. This
> is not why Jobst continues to make such claims as if they were facts
> but that's another story.
From what you say, it seems you are unaware of the source of rolling
losses. Would you explain why a tire that has lower RR than others on
a smooth surface would have poorer performance on a rougher surface?
Jobst Brandt
jobst....@stanfordalumni.org
Benjamin Weiner
> >http://www.terrymorse.com/bike/imgs/rolres.gif
> >Well? If you looked at the curves carefully, you will see that these
> >are a family of curves, their curvature being dependent on their
> >casing losses that reduce with increased inflation pressure. That the
> >tubulars are shifted upward shows how large the glue losses are.
> 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.
Jobst's point in analyzing this plot is that the curves suggest that
rolling resistance of any given tire can be modeled as a constant term
plus a term that depends on inflation pressure. For example
(the rest of this post is my speculation based on previous discussions)
Resistance = C + K / Pressure
would probably provide an acceptable fit to the curves (Whether
it's 1/Pressure, 1/Pressure^2 etc is a side issue). Each tire
might have different values of C and K. The K term is easy to
understand, that comes largely from energy lost to deformation of
the tire and tube at the contact patch, which declines with increasing
pressure. As pressure is increased this term declines and the
resistance gradually approaches some asymptotic value, C.
One might expect that K should depend mostly on the weight and
flexibility of the tire and tube, and not on the method by which
the tire it attached to the rim.
The very gradual curvature of the data for the two tubulars on
that graph suggests that as pressure increases, they asymptote
to a higher C value than the clinchers do. Perhaps about 280 g
vs 220 for the better clinchers. This suggests some additional
source of resistance for tubulars, which Jobst has attributed to
rim glue. If that additional source of resistance were eliminated,
the tubular curves would move down the plot. I don't know
the precise amount and trying to get it off the plot is just
eyeballing.
jobst....@stanfordalumni.org
http://www.terrymorse.com/bike/imgs/rolres.gif
With some good software different 'K' factors could be applied to the
tubular curve until it matched a clincher in shape (being entirely
parallel), the offset would be entirely the glue and easily added or
subtracted. This value (glue loss) would then become numerically
obvious. I found this family of curves are so identical in nature
that their meaning was immediately obvious. There is no other
difference between tubulars and clinchers so it must be the glue, and
as I said, I am painfully aware of that loss from years of riding
these things and seeing the wear on the rim from base tire tape
motion. Besides, the existence of track glue had been nagging me for
many years.
This is the kind of thing researchers need to see at a glance to
arrive at new discovery. The data is before ones eyes waiting to be
understood. It may no longer be apparent today but nearly all the key
elements of spoke failures and wheel strength in "the Bicycle Wheel"
were unknown 20 years ago, and to some in the business they remain a
mystery today as attacks by infidels demonstrate.
Jobst Brandt
jobst....@stanfordalumni.org
JP
> Therefore, since energy cannot be spirited away and we
> know that the tubular tire is lighter, thinner and has less tread and
> tube, the obvious result is that the out of character RR losses must
> be glue.
I don't know. Maybe. The fact that tubulars have a cloth instead of
aluminum sidewall seems to me could lead to more flex and hence
rolling resistance. Shellac could work better because it soaks into
the fibers of the base tapes of tires themselves and rigidifies them,
sorta like fiberglass, not because it avoids "glue flow". I'm not
saying it does, I'm just saying that it's not that hard to come up
with an alternative hypothesis.
Personally, I had always assumed that that dark contaminant that
*sometimes* showed up on a rim was just dirt. Did you do a chemical
analysis on it?
> When we got these curves and data from IRC, it struck all
> who saw them that the two tubulars were way out of character. Having
> much experiences with tubulars at that time my mentioning that it was
> rim glue made the others say "why didn't I think of that?"
I haven't been able to look at the data. Was there any effort made to
insure the quality of the glue job? I would not be comfortable with
the validity a tubular test conducted by clincher advocates and
dependent on them to test the tubular under best possible conditions.
There, there's another alternative hypothesis.
Having cycled in Germany for several years with people whose
experience should have made them aware of it, I never once heard
anyone raise the issue of melting glue on mountain descents. Maybe if
I had spoken better German. But I still would like to see data on the
temperatures at which various glues become squirmy, and how it relates
to the expected rim temperatures during a descent. I'm not asking this
to be argumentative, but because I would really like to know for my
own safety more about under what conditions glue melts.
JP
David L. Johnson
>
> Personally, I had always assumed that that dark contaminant that
> *sometimes* showed up on a rim was just dirt. Did you do a chemical
> analysis on it?
The gray color suggests aluminum oxide.
>
> Having cycled in Germany for several years with people whose
> experience should have made them aware of it, I never once heard
> anyone raise the issue of melting glue on mountain descents. Maybe if
> I had spoken better German.
Were any of your buddies yelling "Scheiss!" during the descent?
> But I still would like to see data on the
> temperatures at which various glues become squirmy, and how it relates
> to the expected rim temperatures during a descent.
I've only experienced it with Clement glue, but it does happen. More,
probably, with fresh glue than with old, but other than that I would
expect a wide range of glues to do this. Since the glue has to remain
sticky in order to hold a spare tire after a field change, it probably has
enough stickiness to melt under field conditions.
--
David L. Johnson
__o | Become MicroSoft-free forever. Ask me how.
_`\(,_ |
(_)/ (_) |
tr...@notarealaddr.com
>Maybe. The fact that tubulars have a cloth instead of
>aluminum sidewall seems to me could lead to more flex and hence
>rolling resistance.
Seems to be the obvious conclusion. Not only do tubular casings have
more flexible casings but they also have more casing fabric relative to
the cross-section. This allows tubulars to be run at lower pressures,
for a more comfortable ride, with higher traction. Add the significant
weight savings and lack of snake bites and you can see the performance
gap is substantial. Small increases in rolling resistance are well worth
these trade-offs unless you're on the track or only ride in a straight
line on clean, dry, perfect pavement.
>Personally, I had always assumed that that dark contaminant that
>*sometimes* showed up on a rim was just dirt. Did you do a chemical
>analysis on it?
It has been done though I don't have a ref. Much of that is in fact
aluminum.
>I haven't been able to look at the data. Was there any effort made to
>insure the quality of the glue job?
Perhaps you're not familiar with Jobst-job research. To sum it up Jobst
only tests the minimum number of carefully chosen variables necessary
to illustrate his hypothesies.
>Having cycled in Germany for several years with people whose
>experience should have made them aware of it, I never once heard
>anyone raise the issue of melting glue on mountain descents.
I don't know if the problem is with melting, unless you're using a cold
weather glue like Tubasti. Most tires will creep, at least on the front
rim, during long descents. To stop this use a different glue, let the
glue dry longer before fitting the tire, or flip the front wheel around
after a long, hot descent.
Tommy Roster
Carl Fogel
[snip]
> I found this family of curves are so identical in nature
> that their meaning was immediately obvious. There is no other
> difference between tubulars and clinchers so it must be the glue
[snip]
> This is the kind of thing researchers need to see at a glance to
> arrive at new discovery. The data is before ones eyes waiting to be
> understood. It may no longer be apparent today but nearly all the key
> elements of spoke failures and wheel strength in "the Bicycle Wheel"
> were unknown 20 years ago, and to some in the business they remain a
> mystery today as attacks by infidels demonstrate.
>
> Jobst Brandt
> jobst....@stanfordalumni.org
Dear Jobst,
Perhaps the blinding light obscured a few of the other ways,
besides glue, in which tubulars may differ from clinchers?
I've heard rumors about different rims, the use of base tape,
integrated construction, and lighter weight.
I look forward to your next episode of Job(st)'s sufferings
in the Book of the Bicycle Wheel Lamentations.
One of the infidels,
Carl Fogel
Carl Fogel
> On 27 Feb 2004 19:10:23 +1300, "Trackie" <r...@net.nz> wrote:
>
> >
> >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 Yanky 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
>
>
> jeverett3<AT>earthlink<DOT>net http://home.earthlink.net/~jeverett3
Dear John,
Awfully nice link to that study about the stickiness
of the different tubular glues.
I noticed that the charts showed that each glue had
its own preference for clear and hard anodized rims,
with some sticking better to clear and some sticking
better to hard.
This might shed some light on why the glues are able to
distinguish between the two kinds of anodized aluminum.
It's a section from the FAQ at:
http://www.anodizing.org/faqs.html.
Carl Fogel
"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 smut on the surface of the part.
Smut 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."
Carl Fogel
[snip]
> >I know that if I were a contender and trying to
> >set a pursuit record, I would use hard glue or clinchers and those
> >clinchers would have minimal tread rubber. The Tipo-00 clement silks
> >used thin latex inner tubes and tread because carbon black increases
> >hysteretic losses in rubber. Latex has the best coefficient of
> >restitution of available rubbers.
>
> You've pretty much described the Andre Dugast tubulars whose bright
> pink latex treads are so conspicuous in many pix from elite track
> championships in recent years.
>
[snip]
> -------------------------------
> John Dacey
> Business Cycles, Miami, Florida
> http://www.businesscycles.com
> Now in our twenty-first year.
> Our catalog of track equipment: eighth year online
> -------------------------------
Dear John,
By heavens, those track racers are secure in their
masculinity!
http://users.tpg.com.au/ricknt/DUGASTSILKlatex.jpg
[Deep voice.] Those damn tires really are pink!
[Mumble.] Black for traction, pink for speed.
Black for traction, pink for speed . . .
Carl Fogel
jobst....@stanfordalumni.org
>> 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
jobst....@stanfordalumni.org
Calvin Jones
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
JP
> JP <SocSecTr...@earthlink.net> wrote:
> >Having cycled in Germany for several years with people whose
> >experience should have made them aware of it, I never once heard
> >anyone raise the issue of melting glue on mountain descents.
>
> I don't know if the problem is with melting, unless you're using a cold
> weather glue like Tubasti. Most tires will creep, at least on the front
> rim, during long descents. To stop this use a different glue, let the
> glue dry longer before fitting the tire, or flip the front wheel around
> after a long, hot descent.
I don't know if "melt" is the right term either but it seems to
describe increased flow from heat. The mountains in and around
Mannheim-Heidelberg, while definitely mountains with challenging
climbs and descents, are not the Alps and do not have descents of the
type Jobst did. However, among the group of pros, ex-pros, amateurs,
tourists and old guys that I got to ride with, I never saw anyone pay
the slightest attention to their tires during descents (they were all
using tubulars). So my point is that since this problem problem only
begins to occur somewhere between the moderate conditions I
experienced and the extreme conditions of alpine descents, some
quantification of the parameters might help to find or develop glues
or systems approaches that withstand the heat under these extreme
conditions. It might be within the range of the most heat resistant
glues already available or even dependent on braking style.
JP
David L. Johnson
> Seems to be the obvious conclusion. Not only do tubular casings have
> more flexible casings but they also have more casing fabric relative to
> the cross-section.
What? Plenty of clinchers have exactly the same casings as corresponding
tubulars, except for that part of the tubular that is stuck onto the rim
with glue. The only way you get "more casing fabric relative to the
cross-section" is to count that part. Functionally, the casing ends at
the point of rim contact, whether that contact is secured by glue or bead.
> This allows tubulars to be run at lower pressures,
> for a more comfortable ride, with higher traction. Add the significant
> weight savings and lack of snake bites
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. 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,
--
David L. Johnson
__o | Let's not escape into mathematics. Let's stay with reality. --
_`\(,_ | Michael Crichton
(_)/ (_) |
Carl Fogel
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 csh...@ku.edu.
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:
Carl Fogel
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....@stanfordalumni.org
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 csh...@ku.edu.
> 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
jobst....@stanfordalumni.org
tr...@notarealaddr.com
>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
> jobst....@stanfordalumni.org 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?
Tom Sherman
> ...
> 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)
jobst....@stanfordalumni.org
>> 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
jobst....@stanfordalumni.org
John Dacey
On Mon, 01 Mar 2004 05:58:33 GMT, jobst....@stanfordalumni.org
wrote:
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.
Mike S.
<jobst....@stanfordalumni.org> wrote in message
news:3wv1c.5617$_3.7...@typhoon.sonic.net...
> 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 crap, 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.
JP
> 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
David L. Johnson
> "David L. Johnson" <david....@lehigh.edu> wrote in message news:<pan.2004.03.03....@lehigh.edu>...
>> 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).
>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.
>
>> 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, 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.
>
>> 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.
True.
--
David L. Johnson
__o | You will say Christ saith this and the apostles say this; but
_`\(,_ | what canst thou say? -- George Fox.
(_)/ (_) |
Carl Fogel
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 csh...@ku.edu.
Carl Fogel
Tom Compton
> 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
> On Thu, 04 Mar 2004 03:55:22 -0800, JP wrote:
>
> > "David L. Johnson" <david....@lehigh.edu> wrote in message news:<pan.2004.03.03....@lehigh.edu>...
> >> 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....@stanfordalumni.org
> 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 csh...@ku.edu.
Yes.
Jobst Brandt
jobst....@stanfordalumni.org
David L. Johnson
> 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.
Only to the extent that it is not securely glued (which is where this
conversation started).
> 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.
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. Yes, the rim provides stability, which lowers the rolling
resistance because there is not the energy losses from the squirm, but
that does not substantially affect the behavior of the that part of the
tire away from the rim.
> 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.
Once pumped up to the pressure needed to support the rider, the holding of
the tire on the rim is achieved for free. It is the rim which holds the
tire, no extra air pressure is needed to hold the tire in place. The rim
serves the same function as the thread holding a tubular together, no
extra pressure needed for that, either.
--
David L. Johnson
__o | the people can always be brought to the bidding of the leaders.
_`\(,_ | That is easy. All you have to do is tell them they are being
(_)/ (_) | attacked, and denounce the peacemakers for lack of patriotism
and exposing the country to danger. It works the same in any
<country. -- Hermann Goering
David L. Johnson
> 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.
--
David L. Johnson
__o | Arguing with an engineer is like mud wrestling with a pig... You
_`\(,_ | soon find out the pig likes it!
(_)/ (_) |
tr...@notarealaddr.com
>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
tr...@notarealaddr.com
>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
jobst....@stanfordalumni.org
>> 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
jobst....@stanfordalumni.org
Tom Sherman
> ...
> 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.
David L. Johnson
That simply is not so. You could not tell whether you had a tubular or a
clincher tire in your hands if someone had cut it off just past where the
tire contacted (one way or the other) the rim. Some clincher tires, such
as Clement, tried to sell themselves as "open tubulars" --- of course,
that would legitimately describe all clincher tires, but that is
marketing. BTW, those tires sold poorly, and are now available for cheap
in swap meets. I got one, Kevlar bead, for $5, which I use as a spare.
--
David L. Johnson
__o | There is always an easy solution to every human problem - neat,
_`\(,_ | plausible, and wrong. --H.L. Mencken
(_)/ (_) |
David L. Johnson
> 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.
I don't think so. For one thing, there really is no added liability issue
with tubulars, most rolled tires being operator error. The other is:
what profits? Tubulars have been a niche market for 20+ years, and no one
is getting rich off of them.
David L. Johnson
> David L. Johnson <david....@lehigh.edu> 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.
Thanks for the chuckle.
> Clement criterium Setas
> may have been the best in their day but nearly any tubular made by
> Vittoria today is several times better.
Sorry. I have ridden Vittoria tubulars in recent years. No. Have you
ever ridden a Clement silk?
--
David L. Johnson
__o | "Business!" cried the Ghost. "Mankind was my business. The common
_`\(,_ | welfare was my business; charity, mercy, forbearance, and
(_)/ (_) | benevolence, were, all, my business. The dealings of my trade
were but a drop of water in the comprehensive ocean of my
<business!" --Dickens, "A Christmas Carol"
Carl Fogel
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
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
Carl Fogel
Dear David, Tommy, and Jobst,
Here's a link to John Dacey's track tire page:
http://www.businesscycles.com/trcomp.htm#tires
It should give some idea of weights and prices,
but I have no idea how to compare long-vanished
tires to what's available today in terms of
reliability or performance.
I vaguely recall Jobst posting about track silks
exploding if treated carelessly. Could this be
the kind of reliability problem Tommy is getting
at?
Is it fair to say that tubulars are pretty much
limited to track use now?
Would you say that the pink latex silks that John
Dacey sells are roughly as painful to buy as whatever
was available and comparable twenty or thirty years
ago before clinchers overwhelmed tubulars?
Have cotton tubulars improved, or are silks just
too expensive to make for such a small market?
What are the advantages of silk over cotton?
Lightness, strength, lower rolling resistance?
Does anyone know of a recent rolling resistance
table for tubulars that might be compared to
what Jobst's 1986 table showed for two tubulars?
I'm curious whether the tubular situation is roughly
similar to the motorcycle world's 50cc class, where
no modern machines come near the Lilliputian grandeur
of the 1960's when Honda and Suzuki went mad and
fought for the world championships with ever more
incredible miniature engines. Once the two giant
companies came to their senses, the bottom dropped
out of the 50cc racing world.
But I suppose that Tommy could be right and that
modern tubulars have improved. Have the rims or
base tape improved from a racing point of view?
Carl Fogel
Mike S.
<snip>
>
> 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.
>
lighter tires. I am a trackie by nature, and have even seen some 110g tires
in the last year or so.
I actually had a 130-140g tire for about 4 races... Cords wore thru 'cause
there just wasn't enough rubber.
I haven't had the pleasure of racing silk tires. They were on their way out
as I was getting into cycling. I couldn't see the need to afford them.
> I think you are not aware of the tires you imagine were poorer than
> those available today.
Actually, one of the tires that I think would probably still work is the
Wolber Invulnerable. Something nice and reassuring about steel mesh under
your tread... Yeah, I know kevlar does a better job, but still...
steeelllll... mmmmm.
I will say that the selection of tubulars is fewer and farther between than
it used to be. With only a small percentage of riders knowing WTF they're
doing, and willing to do it, tubulars are destined to be "too much hassle,
and too expensive." Pity. The only thing stopping the trend of tubulars
vanishing completely are trackies and carbon aero rims. ...and they're
trying like hell to get a carbon clincher that'll stay together!
Mike
Mike S.
"David L. Johnson" <david....@lehigh.edu> wrote in message
news:pan.2004.03.05....@lehigh.edu...
> On Fri, 05 Mar 2004 02:58:41 +0000, tros wrote:
>
> > David L. Johnson <david....@lehigh.edu> 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.
>
> That simply is not so. You could not tell whether you had a tubular or a
> clincher tire in your hands if someone had cut it off just past where the
> tire contacted (one way or the other) the rim. Some clincher tires, such
> as Clement, tried to sell themselves as "open tubulars" --- of course,
> that would legitimately describe all clincher tires, but that is
> marketing. BTW, those tires sold poorly, and are now available for cheap
> in swap meets. I got one, Kevlar bead, for $5, which I use as a spare.
>
IIRC, Conti tubulars are the same as their clinchers except for that
bead/base tape thing. Comp = Grand Prix, Sprinter = Ultra. Look on the
boxes...
Mike
Tom Sherman
> On Thu, 04 Mar 2004 21:24:46 -0600, Tom Sherman wrote:
>
>
>>I wonder if some manufacturers are stopping producing tubular tires for
>>street use due to liability reasons. The legal cost alone of setting a
>>single lawsuit would likely be more than the yearly profit from tubular
>>sales.
>
>
> I don't think so. For one thing, there really is no added liability issue
> with tubulars, most rolled tires being operator error. The other is:
> what profits? Tubulars have been a niche market for 20+ years, and no one
> is getting rich off of them.
Going to court and proving that a tubular tire rolled off the rim due to
operator error would cost several hundred thousand dollars. Settling
lawsuit out of court would typically cost more than fifty thousand
dollars in legal fees alone.
A Muzi
>>>Actually, I notice that you ignored my question about when you rode
>>>tubulars and whether your tubular rims were anodized, hard anodized,
>>>or polished:
>>>>>Whether the glue fails most often at the tire's base tape or at
>>>>>the rim sounds like a good question. But your experience in the
>>>>>years that you rode tubulars might differ from the kinds of rims
>>>>>tested in 1995. After all, these rims were anodized and hard
>>>>>anodized. Do you recall what kind of rims you were gluing to?
> jobst....@stanfordalumni.org wrote in message news:<JFN1c.5860$_3.8...@typhoon.sonic.net>...
>>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.
-snip snip snip-
Carl Fogel wrote:
-snip much-
> 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.
Cotton hasn't changed.
Anodized or polished rims exhibit no difference whatsoever
in glue adhesion (aside from gross negligence of a raw
aluminum rim with polishing crud still on the surface).
Jobst refers to the nature of mastic cements. AFAIK no one
is advocating a rigid epoxy or some such adhesive here. All
pliable cements will exhibit thermal breakdown at expected
rim temperatures on the routes Jobst famously describes.
I ride tubulars exclusively and I'm quite satisfied
especially given the price and quality improvements of the
last five or eight years. [I'll probably not outlive my
supply of vintage #6 and #13 setas for the one bike I still
use them on. Its mileage is pretty low nowadays. No time.]
Given routes, temperatures, road surface and hills, I have
never experienced tire shift from braking heat _ within a
day's ride of here_. I have seen that phenomenon on a steep
long descent. It's a true and predictable effect. Just not
here, a thousand miles from a mountain.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
SMMB
Lawyers' fees of around 20-25K ; plus experts, through a trial, should cost
around 8K ; so around $35K. And the defense is going to be commensurate
with the damages. Settling, if there is real fault in other than the
complaining party, may not get beyond the adjuster, if insured.
If you are just whining about skinned knees and a little bike damage, no one
would pay attention. Nuisance award.
--
Bonne route,
Sandy
Paris FR
"Tom Sherman" <tshe...@qconline.com> a écrit dans le message de :
news:c29pq3$1qg1h6$1...@ID-81487.news.uni-berlin.de...>
JP
>
> > 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.
>
> Only to the extent that it is not securely glued (which is where this
> conversation started).
Well, of course. The limit on flex is where the tire is glued
perfectly, meaning no flex at all between the edges of the rim,
something presumably impossible to achieve. But this would make
documentation and standardization of the gluing technique and material
utterly critical to any analysis of the rolling resistance of
tubulars, just as it would be to any analysis of glue performance
under the high temperature conditions caused by extended high speed
downhill braking.
> > 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.
>
> Yes, the rim provides stability, which lowers the rolling
> resistance because there is not the energy losses from the squirm,...
I don't think I ever suggested more than this.
> > 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.
>
> Once pumped up to the pressure needed to support the rider, the holding of
> the tire on the rim is achieved for free. It is the rim which holds the
> tire, no extra air pressure is needed to hold the tire in place. The rim
> serves the same function as the thread holding a tubular together, no
> extra pressure needed for that, either.
If you say so. It would follow then that there is no particular reason
to pump clincher tires to a higher pressure than tubulars, and it
seems to me that we have eliminated pinch flats with the force of pure
logic. Or perhaps the pressure needed to support the rider while
moving under real world conditions is about 120psi.
JP
JP
> 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.
>
> 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.
This all makes sense to me now. Constant hard braking because on dirt
your speed is much more limited by traction than air resistance. And
Mr. Cinelli would of course recall the days when much of the climbing
and descending in the classics was done on unpaved roads. It seems
like the great solutions may have been paved roads for road bikes and
mountain bikes for dirt roads, obviating the need for research into
glues that resisted higher temperatures (although I don't think it has
been established that such research has not been conducted, nor that
such glues are not currently available).
JP
David L. Johnson
> If you say so. It would follow then that there is no particular reason
> to pump clincher tires to a higher pressure than tubulars,
No, that would not follow at all. The sharper edge of the clincher rim is
real, and is the reason you need to be careful about inflation pressure
with clinchers.
> seems to me that we have eliminated pinch flats with the force of pure
> logic. Or perhaps the pressure needed to support the rider while moving
> under real world conditions is about 120psi.
No, and I don't use that much pressure with clinchers, either. I use
about 110psi for 23mm clinchers, and I used about the same for tubulars.
The real difference with clinchers is that you have to be vigilant about
checking tire pressure, since if it falls much you will have to worry
about pinch flats. In both cases, though, the optimum inflation pressure
is about the same. You _can_ use lower pressures with tubulars, but that
will add to the rolling resistance with not much comfort benefit.
--
David L. Johnson
__o | You will say Christ saith this and the apostles say this; but
David L. Johnson
> 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.
True.
> 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 didn't claim no change, I claim degeneration. Tubular tires have always
been a cottage industry, involving a lot of hand labor. It is fast
becoming a lost art, with most surviving tires being machine-produced
compromises to the original design. I really wish I could find some old
good tires to show people the construction that was used. These days, the
biggest brag about a particular tire is that it is round and straight.
Gee, such standards.
> 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 think you are over-estimating the differences. General construction
should not be an issue, since the same processes are used on both, except
for the bead/vs/seam. I think rim differences are minor in this regard,
as are base tape. OK, though, this is not backed up by testing. I'm a
theoretical type.
> But I doubt that this test will ever be happen,
Mostly because the market is so small now.
> 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
Such bargains!. No standard-size tubular at all under $72.95, and the
silks at least twice that. My. I notice you can also still get Clement
track silks, the 170g version, for only $139.50. I wonder if it is the
same as I bought, for maybe $15, back in 1971 or so... That was a great
tire; very durable and very fast. I still have one, which I have cut up
into pieces to use as boot material.
> 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.
I choose b.
> Do you know of any
> recent studies of the performance difference between current cotton and
> silk tubulars?
No, I don't. Maybe the prejudice from the old days against cotton was not
so much due to the material as the workmanship, since cotton tires were
cheap. The tank-like Clement Alvisio (sp?) weighed over 300 grams, had
very coarse cotton casing, and lasted less than 1000 miles in my
experience. It cost $6.50 or so, versus only twice that much for silk
Campionato del Mundo, a 280-gram dream of a tire. There were better
cotton tires, but little demand for them because silk was so much better
at about the same price.
Of course, there has been huge inflation since then. But tire prices are
kept low by the existence of cheap, but good, clinchers. You can get an
Avocet, which to my mind rides just like the old del Mundo, for $25 on
sale. Handmade tubulars can't be made of any material at that price, or
anywhere near it. Accounting for inflation, actually the prices of the
tires you pointed out are in line with the old days, but our expectations
aren't.
--
David L. Johnson
__o | Accept risk. Accept responsibility. Put a lawyer out of
_`\(,_ | business.
(_)/ (_) |
David L. Johnson
> Dear David, Tommy, and Jobst,
>
> Here's a link to John Dacey's track tire page:
>
> http://www.businesscycles.com/trcomp.htm#tires
>
> It should give some idea of weights and prices,
> but I have no idea how to compare long-vanished
> tires to what's available today in terms of
> reliability or performance.
As I mentioned on another sub-thread, the only tire on that list
surviving from the early '70s is the Clement silk 170g tire. It was the
workhorse track tire. Very nice. Price is comparable to todays,
adjusting for inflation. Problem is, you can get clincher tires that are
as nice for $40, and they are nearly as light. Rims aren't, of course.
> I vaguely recall Jobst posting about track silks exploding if treated
> carelessly. Could this be the kind of reliability problem Tommy is
> getting at?
I missed Tommy's issue, but the problem with the track tires was only that
the sidewalls were totally unprotected. It was naked silk threads, and
they could easily abrade if the wheel was mishandled. I used to use old
tubular tires, cut open, as tire covers to protect them. Other than that
the only reliability issue would be the very thin latex tube, which would
rot if not properly stored.
>
> Is it fair to say that tubulars are pretty much limited to track use
> now?
No. Pro road racers use them. They have mechanics to take care of them,
though. Maybe some amateurs do. I also see a smattering of old farts on
club rides with them. Hell, I used to be one.......... No, I'm still an
old fart, but I gave up on the tubulars.
>
> Would you say that the pink latex silks that John Dacey sells are
> roughly as painful to buy as whatever was available and comparable
> twenty or thirty years ago before clinchers overwhelmed tubulars?
Probably. Latex tread tires were rare at the San Jose velodrome, since
the track back then would have torn them to shreds. But I did see a few.
I imagine they were expensive then, too. But then you could buy a bike
for $200 (nice track bike), so $30 tires would seem about the same as
$220 tires now.
>
> Have cotton tubulars improved, or are silks just too expensive to make
> for such a small market?
Silks probably required more hand labor -- skilled hand labor. Plus, the
market is much smaller now.
> What are the advantages of silk over cotton?
> Lightness, strength, lower rolling resistance?
Silk did not stretch under load, so was ideal as casing material. It was
also much stronger for a given thread size, and did not rot like cotton
does. Rolling resistance is proportional to weight, and so you could
build a very low rolling resistance tire using silk.
> But I suppose that Tommy could be right and that modern tubulars have
> improved. Have the rims or base tape improved from a racing point of
> view?
I would imagine not, if there is any validity to the glue-sticking problem
on anodized rims.
--
David L. Johnson
__o | It doesn't get any easier, you just go faster. --Greg LeMond
_`\(,_ |
(_)/ (_) |
dvt
> I would imagine not, if there is any validity to the glue-sticking problem
> on anodized rims.
I can vouch for the fact that some types of anodized aluminum are much
more difficult to adhere than bare aluminum. I spent a few months last
year finding a procedure that coated hard anodized aluminum with good
peel strength (>20 piw).
Here are a few things I found: sealed hard anodizing is very difficult
to adhere. The aluminum oxide coating has low surface energy. Unsealed
type II anodizing was easier to adhere. I specified unsealed to leave
pores in the aluminum surface, and maybe those pores contributed to the
mechanical strength of the bond. I'll probably never know. I wasn't able
to use bare aluminum, but according to adhesive manufacturers, bare
aluminum is the easiest to adhere.
--
Dave
dvt at psu dot edu
Carl Fogel
Dear Andrew,
You may be right when you say that "anodized or polished
rims exhibit no difference whatsoever in glue adhesion."
But the study by Professor Howat and Calvin Jones seems to
show that even anodized and hard anodized rims do exhibit
such a difference:
http://www.engr.ukans.edu/~ktl/bicycle/Cusa1.pdf
For example, the first chart calibrates Vittoria Mastik
One on a hard anodized rim as a stickiness of 1.00, but
on a merely anodized rim, it drops to what looks like
about 0.93.
The next best brand, Continental, drops to 0.80 on hard
anodized and even further to 0.70 on merely anodized.
Pana cement, the weakest glue, reverses the pattern and
does best on merely anodized rims, about 4.2, and only
3.9 on hard anodized rims.
Here's my eyeball take on that bar chart:
Adhesive Performance Continental 250 Sprinter Tires
Plain-Anodized
| Hard Anodized
| | change from plain to hard
| | |
0.42 0.39 -0.03 Pana
0.50 0.51 +0.01 Vittoria Gutta
0.56 0.54 -0.02 Wolber
0.63 0.57 -0.06 3M Fast Track
0.61 0.71 +0.10 Clement
0.71 0.81 +0.10 Continental
0.93 1.00 +0.07 Vittoria Mastik One
While some of these changes between how a glue sticks
to one rim or the other are quite small, they look like
about 10% or more on the two best glues.
Of course, this variation between rims could be
merely the range of experimental error, but it
looks as if the best glue is about twice as sticky
as the worst. If I ever decide to paste my tires
onto my wheels with frog snot, I'll look in the
Vittoria Mastik One pond.
You could also be right in the practical sense if
all the glues stick to all the rims well enough
that they never come off. With luck, Jobst will
get the details from Professor Howat, do the hard
work for us, and explain just how sticky things
are, how it was all tested, and what practical
limits exist.
Carl Fogel
Tom Sherman
> ...Just not here, a thousand miles from a mountain.
I guess that the "Ocooch Mountains" do not really count as mountains.
They do give flatland cyclists quite a workout, however.
A Muzi
>>Cotton hasn't changed.
>>Anodized or polished rims exhibit no difference whatsoever
>>in glue adhesion (aside from gross negligence of a raw
>>aluminum rim with polishing crud still on the surface).
-blah blah blah-
Carl Fogel wrote:
> You may be right when you say that "anodized or polished
> rims exhibit no difference whatsoever in glue adhesion."
>
> But the study by Professor Howat and Calvin Jones seems to
> show that even anodized and hard anodized rims do exhibit
> such a difference:
-snip-
> Plain-Anodized
> | Hard Anodized
> | | change from plain to hard
> | | |
> 0.42 0.39 -0.03 Pana
> 0.50 0.51 +0.01 Vittoria Gutta
> 0.56 0.54 -0.02 Wolber
> 0.63 0.57 -0.06 3M Fast Track
> 0.61 0.71 +0.10 Clement
> 0.71 0.81 +0.10 Continental
> 0.93 1.00 +0.07 Vittoria Mastik One
I'll freely admit that if there is truly an average 5%
difference and the entire range is safely below any danger
of a tire rolling, then I wouldn't know about that, wouldn't
have noticed and still maintain, rephrased "no practical
difference" (rather than "none whatsoever" which does seem a
bit strong.)
[nice ascii chart, BTW]
Semantically yours,
A Muzi
>> ...Just not here, a thousand miles from a mountain.
Tom Sherman wrote:
> I guess that the "Ocooch Mountains" do not really count as mountains.
> They do give flatland cyclists quite a workout, however.
Very figurative. At least within a day's ride, you can't
melt tub glue on a hill by braking.
(and haven't been to that mountain, either)
Tim McNamara
> Here are a few things I found: sealed hard anodizing is very
> difficult to adhere. The aluminum oxide coating has low surface
> energy.
Eh? What does that mean, and what does it have with gluing something
to it? I don't know nothin' about how adhesives actually work.
JP
> On Fri, 05 Mar 2004 07:47:50 -0800, JP wrote:
>
> > If you say so. It would follow then that there is no particular reason
> > to pump clincher tires to a higher pressure than tubulars,
>
> No, that would not follow at all. The sharper edge of the clincher rim is
> real, and is the reason you need to be careful about inflation pressure
> with clinchers.
In other words, you have to keep the tires pumped up to a very high
pressure to keep them seated so the tube does not have a chance to
come in contact with this sharp edge.
> No, and I don't use that much pressure with clinchers, either. I use
> about 110psi for 23mm clinchers, and I used about the same for tubulars.
110, 120 what's the difference? 110 psi is more than just minimal
pressure that you said was necessary to seat the tire and keep it
seated. There's no real need to pump up a tubular that high, and a
tubular can be ridden on any air pressure from 0-120psi and it will
still not get a pinch flat.
> You _can_ use lower pressures with tubulars, but that
> will add to the rolling resistance with not much comfort benefit.
That is a subjective judgement and there are plenty of people who
disagree with you.
JP
David L. Johnson
>> No, that would not follow at all. The sharper edge of the clincher rim is
>> real, and is the reason you need to be careful about inflation pressure
>> with clinchers.
>
> In other words, you have to keep the tires pumped up to a very high
> pressure to keep them seated so the tube does not have a chance to
> come in contact with this sharp edge.
No, that is not how a snake bite works. A snake bite is when the tube is
pinched between the two layers of the tire, one contacting the road, the
other just past the bead. If the tire came unseated, the tube would pop
with a rather loud report.
--
David L. Johnson
__o | If all economists were laid end to end, they would not reach a
_`\(,_ | conclusion. -- George Bernard Shaw
(_)/ (_) |
Tom Paterson
> There's no real need to pump up a tubular that high, and a
>tubular can be ridden on any air pressure from 0-120psi and it will
>still not get a pinch flat.
I hit a rock once or twice (riding on dirt roads), tubular tire went flat. Have
seen others do the same. Also got forced wide in a crit once, got the front
wheel over the curb but not the back. Flat (pow!) that time too. If those
weren't pinch flats, what were they, please? --TP
jobst....@stanfordalumni.org
> 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.
There is no market for them. That's the reason they have not been
further developed and why so few are made.
Jobst Brandt
jobst....@stanfordalumni.org
jobst....@stanfordalumni.org
>> 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.
Beyond saying that it is so, can you explain how these tires differ
and what effect these differences have in a comparative way? Such
statements would be more convincing backed up by some explanation why
one should believe such things.
I think you'll notice that the tubular tire does not flex or change
its cross section in the region between the rim contact edges, the
tire being deformed into an oval outside the contact with the rim. I
see no difference between this and a clincher and in fact on cannot
discern a tubular form a high performance clincher without careful
close up inspection the being no visible difference.
Please explain what you had in mind.
Jobst Brandt
jobst....@stanfordalumni.org
Mike Krueger
<< There is no market for them. That's the reason they have not been
further developed and why so few are made.
Continental, Veloflex, Clement, Hutchinson, Vredestein, Tufo, and Gommitalia
all offer tubulars, not to mention Vittoria, who has introduced an extensive
new range of re-engineered tubulars this year. Plenty of amateurs still prefer
tubulars, as do most of the pro riders in Europe.
Carl Fogel
> > A Muzi wrote:
> >> ...Just not here, a thousand miles from a mountain.
>
> Tom Sherman wrote:
> > I guess that the "Ocooch Mountains" do not really count as mountains.
> > They do give flatland cyclists quite a workout, however.
>
> Very figurative. At least within a day's ride, you can't
> melt tub glue on a hill by braking.
>
> (and haven't been to that mountain, either)
Dear Andrew,
I hadn't even heard of Wisconsin's answer to the Andes:
http://www.trails.com/explore/Tcatalog_trail.asp?TrailID=BGM006-038
"Here's a tour to take on once you've gotten your climbing
legs in shape. You'll have to tackle four steep, 400-foot cli..."
I look forward to "Andrew Muzi's Tour of the Ocooch" page.
Carl Fogel
Carl Fogel
Dear David,
Where tubulars are concerned, it's all theoretical
to me, so I enjoyed all your details.
So here's a truly ignorant question: compared to silk
or cotton, would Kevlar be better, worse, the same,
or impossible?
Thanks again for the interesting post,
Carl Fogel
Charles Hizark
I think that tire sidewall technology has improved a lot over the
years. One downsided is that the prices of tires has increased a lot
over the years. It almost seems better to spend the money on a tubular
instead. On the otherhand sewups are still a lot more comfortable and
handle better.
> 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
> jobst....@stanfordalumni.org
Zog The Undeniable
> There is no market for them. That's the reason they have not been
> further developed and why so few are made.
It's admittedly a small market, but they're still strongly recommended
on the track (although not mandatory). As a very occasional track rider
who always has to use the loan bikes, I've never actually looked to see
what type they're using. I spend long enough trying to find one with a
vaguely straight wheel.
David L. Johnson
> So here's a truly ignorant question: compared to silk
> or cotton, would Kevlar be better, worse, the same,
> or impossible?
Well, there are some synthetic-fiber tubulars available. The first ones
were nylon, and had to be so small to begin with (since the thread
stretched) that they were damn near impossible to put on. I have tried
some modern ones, but I am not sure what the fibers were; probably a lot
of polyester, but maybe some aramid (kevlar) as well. I would imagine
kevlar would be pretty good, since it does not stretch and is very strong,
but I don't know how it is used for tubular tires.
--
David L. Johnson
__o | You will say Christ saith this and the apostles say this; but
Tom Sherman
Dear Carl,
I used to live in Richland Center and I have most likely ridden the
"four steep, 400-foot cli..." on the Peugeot P-8 [1] I purchased from
Andrew Muzi back in the Dark Ages. While 400-ft of elevation gain may
not sound like much to a Coloradan, it becomes quite challenging when
the climb is less than a mile long. I did not find the hills too bad at
the time, since I was 14 years old and had a body fat percentage that
many in the UCI peleton would have been jealous of (sadly this is no
longer the case).
[1] Regrettably destroyed by a stop sign running truck.
David L. Johnson
> jobst....@stanfordalumni.org wrote in message news:<JeS1c.5959$_3.8...@typhoon.sonic.net>...
>
> I think that tire sidewall technology has improved a lot over the
> years. One downsided is that the prices of tires has increased a lot
> over the years.
You are dreaming. Compared to inflation, high-quality (clincher) tire
prices have become a bargain. When I was 21, I paid $20 for a good tire.
I paid $24 recently for one almost as good. I was 21 a long, long time
ago.
> It almost seems better to
> spend the money on a tubular
> instead.
Tubular tire prices are much closer to keeping up with inflation. They
are severly undercut by clincher tires, for equivalent performance.
> On the otherhand sewups are still a lot more comfortable and
> handle better.
I don't think so.
--
David L. Johnson
__o | If all economists were laid end to end, they would not reach a
Carl Fogel
> On Mon, 08 Mar 2004 12:38:56 -0800, Carl Fogel wrote:
>
> > So here's a truly ignorant question: compared to silk
> > or cotton, would Kevlar be better, worse, the same,
> > or impossible?
>
> Well, there are some synthetic-fiber tubulars available. The first ones
> were nylon, and had to be so small to begin with (since the thread
> stretched) that they were damn near impossible to put on. I have tried
> some modern ones, but I am not sure what the fibers were; probably a lot
> of polyester, but maybe some aramid (kevlar) as well. I would imagine
> kevlar would be pretty good, since it does not stretch and is very strong,
> but I don't know how it is used for tubular tires.
Dear David,
Good lord, I hadn't thought of nylon!
I always get muddled with Kevlar. I keep reading that
Kevlar-bead tires are stretchier, but that's compared
to steel-wire bead. So when you say that Kevlar doesn't
stretch, are you comparing it not to steel, but to
cotton and silk?
Carl Fogel
jobst....@stanfordalumni.org
> So here's a truly ignorant question: compared to silk or cotton,
> would Kevlar be better, worse, the same, or impossible?
No. Kevlar has high losses and does not adhere well to inter-ply
casing elastomers. This was first discovered with Kevlar belts to
prevent flats. If the belt is thick enough to do much good, the tire
performs like a slug. That is why Kevlar belts don't do much good,
they being made so thin to leave some life in the tire.
Silk has far more strength than cotton because the filaments are many
times longer that the longest filament in a cotton boll. Cotton
relies partly on filament overlap and friction to give its thread
tensile strength. Silk can do that with far fewer filaments because
they are so long. Thin casings that could hold high pressure were two
important features of silk tires, and of course the resulting weight.
These tires were truly paper thin.
Jobst Brandt
jobst....@stanfordalumni.org
JP
> On Sat, 06 Mar 2004 09:23:55 -0800, JP wrote:
>
>
> >> No, that would not follow at all. The sharper edge of the clincher rim is
> >> real, and is the reason you need to be careful about inflation pressure
> >> with clinchers.
> >
> > In other words, you have to keep the tires pumped up to a very high
> > pressure to keep them seated so the tube does not have a chance to
> > come in contact with this sharp edge.
>
> No, that is not how a snake bite works. A snake bite is when the tube is
> pinched between the two layers of the tire, one contacting the road, the
> other just past the bead. If the tire came unseated, the tube would pop
> with a rather loud report.
Maybe but I'm not entirely unconvinced that there could not be a pinch
between the bead and some spot in the interior of the rim, as the bead
is suddenly forced away from the hook on the flange toward the base of
the rim. I don't ride clinchers so I have no personal experience about
it, nor have I read about how pinch flat are supposed to happen. You
are probably basing your knowledge on high speed photography that
someone has done to investigate the phenomenon.
Nevertheless, tubulars can be ridden at almost any pressure without
risk of pinch flats, unlike equivalent width clinchers which have a
pretty narrow inflation range.
JP
Tom Paterson
>Nevertheless, tubulars can be ridden at almost any pressure without
>risk of pinch flats, unlike equivalent width clinchers which have a
>pretty narrow inflation range.
You can "pinch" either clinchers or tubulars. Or at least I can. It takes a
bigger tire to prevent clincher flats than tubular flats, other factors being
approx. equal.
--TP
David L. Johnson
> I always get muddled with Kevlar. I keep reading that
> Kevlar-bead tires are stretchier, but that's compared
> to steel-wire bead. So when you say that Kevlar doesn't
> stretch, are you comparing it not to steel, but to
> cotton and silk?
No, to nylon and polyester. Read Jobst's reply to your question, which
will explain why kevlar is not a good casing material.
--
David L. Johnson
__o | "Business!" cried the Ghost. "Mankind was my business. The common
_`\(,_ | welfare was my business; charity, mercy, forbearance, and
(_)/ (_) | benevolence, were, all, my business. The dealings of my trade
were but a drop of water in the comprehensive ocean of my
<business!" --Dickens, "A Christmas Carol"
Carl Fogel
Dear Jobst,
Another excellent explanation!
I take it that the strength of silk allows its
paper-thin construction, which in turn reduces
rolling resistance--not much left to deform.
Thanks,
Carl Fogel