More glue is better

Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. More goo reduces rolling resistance:
http://www.biketechreview.com/forum/...php?f=1&t=2347

Robert Chung mentioned the thread over on RBR.

Cheers,

Carl Fogel

Carl Fogel wrote:

Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. More goo reduces rolling
resistance:

http://www.biketechreview.com/forum/...php?f=1&t=2347

Robert Chung mentioned the thread over on RBR.

Carl, you're trolling, considering how often the RR tests have been
discussed here. For those who are not aware of the circumstances
under which the most commonly sued tires were tested for RR, let me
repeat.

When Avocet introduced smooth tread on their tires (slicks), knowing
that IRC had made them with a new tread compound that was claimed to
wear better, have better traction and lower RR. The cornering was
never tested other than on a bicyle on a tilt-bed of asphalt on which
45° was the limit, but then it seemed that that was not substantially
different from good tubulars.

Then RR was tested with the same tubes for clinchers and all tires the
same size inflated to a series of pressures. The results were widely
shown in magazines and here on the web. It was there that I
discovered why there were two kinds of tubular glue after inquiring
everywhere from shops and riders for the two types.

You'll nootice that the tubulars that have thinner tread rubber and
more flexible sidewalls... and thin latex tubes showed that they had
inherent low RR by their response to changinf inflation pressure
(almost none). BUT - they had poorer overall RR than the best
clinchers with heqvier casings, tubes and tread thickness.

Having ridden tubulare for more than 30 years, I was aware that they
moved on the rim so much that the rim glue and base tape were grey
with aluminum wear materoial and ultimately tires occasionally failed
when the base tape wopre through. THis did not occur with track glue
(shellac) that rigidly (hard glue) secured tires so much so that they
were difficult to remove manually.

Track glue was used to reduce RR to the intrinsic values one expects
of such a light casing, tube, and tread. This was practical because
at the track one grabs another wheel if a tire has a flat. On the
road, tires needed to be changed by hand before the days of wheel
changes by equip-cars.

Here you can see the values:

http://www.sheldonbrown.com/brandt/r...e-tubular.html

================================================== ==================
The following scenario is unbelievable and contrary to measured values:

http://www.biketechreview.com/forum/...php?f=1&t=2347

The text:

Bottom line is that it is much better to use too much glue than not
enough - Mastik 1 may be better than Conti.

Long story but I was contacted by a rider last August a month before
an important international race - she was trying to decide whether to
go with clinchers or tubulars. The had a tubular Zipp 900 disc with a
Vittoria Crono on it. The tire had been glued 2 months previous using
Mastik 1 glue (2 tubes I was told) - the process was 2 coats on the
rim and 2 coats on the base tape with 24 hours to dry between each
coat - then a third coat on the rim and immediately mount the tire -
the tire had zero miles on it when I tested it. I was a bit skeptical
about the outcome as the consensus and my belief was that a thin and
hard glue layer would be less compliant and would reduce the losses
due to compression of the glue. Well I did the test and got a Crr of
0.00225 - Wow!! Quickly emailed the result which was very well
received as she really wanted to race on tubulars. She couldn't pick
up the wheel right away so I told them I'd retest the next day to
confirm although my control tire looked. Funny as she tried to talk
me out of it fearing a bad result which would put them back on
clinchers - I guess confidence in equipment is a big factor at that
and any level of racing. Did the follow up test and it was actually a
bit better. Subsequently I've repeated the test using 5 different
Crono tires glued the same way on five different wheels including my
36 spoke Mavic Reflex rimmed test wheel. The first tire seems to be a
hot one but the other 4 all had Crr's of ~ 0.00235. The Crono is both
fast and narrow but not particularly durable - I've flatted one at
Natz as did JV and Nico has also lost 2 but not in a race. All of
these were in wet conditions. Have received reports from others on
flatting of Cronos as well.

I've also been talking with Jack Watts who has been doing his own
testing and also confirmed good results with the "too much glue"
process. He has gotten good results with the Vittoria CX 20 and 23
and also reported that the Bontrager RXL Pro Tubular was fast. Damon
graciously sent me out another Bonty which I tested last week (full
disclosure - he allowed me to keep the tire after the test). It was
installed on a Zipp 900 disc and was used by my wife in the rain at
Moriarty on 8/30/08 - about 20 miles total on it. I glued it using a
slight variation (suggested by Jack) on the "too much glue" procedure
(3 coats of Mastik 1 on the rim and 2 coats on the tire - 24 hours
between each coat except for the last coat on the rim). I had
previously immediately installed the tire after that fresh coat on the
rim. The problem with that process is that it gets very messy - the
Mastik 1 sets up quickly and centering the tire can be a problem. I
used 4 coats on the rim but allowed the last coat to dry for ~ 2
hours. Installing and centering the tire was much, much easier.
Additionally I did not remove the latex coating on the base tape.

Results were quite good. The raw test yielded Crr of 0.00235 but it
was warm at 76F. Correcting to 68F the Crr was 0.00245. The Bonty
measured 21.2 mm in width so is fairly narrow. I may switch the rear
tires to the Bonty's. Giving up a tad of rolling resistance but I'm
sure they are more reliable. The Cronos are probably good on the
front as they won't see stuff kicked up by a lead tire and they are
more narrow. It would be interesting to test out the Vittoria Evo CX
tubulars as well.

When testing tubulars initially I was using a 2 coats of Continental
glue on the rim of my test wheel with no glue on the tire so as to
minimize the affect on the tire for future use/sale. The tire was
fairly easy to remove but seemed to be stuck quite well to the rim.
This was described to me as the "triathlete process" - so named as it
was easy to remove and reinstall a tubie in the midst of a race. Most
of the tubular tires in the list were installed in this manner
although some were given to me already glued onto wheels. For the
Crono and Bonty the Crr results are much better with more layers of
Mastik 1. The Bontrager RXL Pro tested at 0.00276 with light glue and
0.00245 with Mastik 1. A similar improvement as seen in the Crono
which went from 0.00276 to ~ 0.00235.

So, have we come full circle on gluing? Possibly the old timers had
it right but more for reliability? In my initial tubular tests using
2 light coats of Conti glue on the rim only, it seemed as though the
tires were stuck on sufficiently but obviously not. My thought is
that it is imperative to achieve a solid bond over 100% of the base
tape. I'm wondering if a lot of the tests out there showing the
relatively poor performance of tubulars is due more to incomplete glue
bond than compression of the glue layer? As Jack points out and
published over on ST - this glue method is not a good option for
triathletes who need to be able to change tires quickly on the road.
It literally took me a couple of days to get the flatted Crono off my
disc - I'm sure that pro mechanics could do it much, much faster but
those tires are stuck on! Arguing based exclusively on rolling
resitance the best option in a triathlon are the fast clinchers IMHO.
================================================== ====================

Jobst Brandt

On 18 Sep 2008 01:56:11 GMT, wrote:

Carl Fogel wrote:

Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. More goo reduces rolling
resistance:

http://www.biketechreview.com/forum/...php?f=1&t=2347

Robert Chung mentioned the thread over on RBR.

Carl, you're trolling, considering how often the RR tests have been
discussed here.

[snip]

Dear Jobst,

Nope, I'm posting a link to a thread about glue on tubulars.

Robert Chung found Kraig's comments plausible.

If you have tests showing anything about glue thickness, let us know.

Cheers,

Carl Fogel

Carl Fogel wrote:

Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. More goo reduces rolling
resistance:

http://www.biketechreview.com/forum/...php?f=1&t=2347

Robert Chung mentioned the thread over on RBR.

Carl, you're trolling, considering how often the RR tests have been
discussed here.

Nope, I'm posting a link to a thread about glue on tubulars.

Robert Chung found Kraig's comments plausible.

If you have tests showing anything about glue thickness, let us know.

The whole idea of a thick layer of glue acting as a sponge,
compressively absorbing tubular tire radial motion, is bizarre. That
is not where losses occur, but rather in shear of the glue film as the
tire cross section changes from its original unloaded round, to a
flattened oval in the road contact area, and back to round. This is
shown by base tape wear and the reason for using hard glue (tipo
pista) where tire changes are not anticipated and 1/100 of seconds are
at stake in competition.

Tubular tires sit nicely in the semicircular recess of rims when
inflated with no load. When the tire deforms, bulging laterally in
the load affected zone, tension causes tire casings to take a shorter
path across the rim, raising at midpoint out of the "groove" in the
rim. This causes lateral shift on rim side ridges and shears the glue
while abrading the base tape. Any used tubular that was on an
aluminum rim will have grey aluminum debris on the edge of the glue
zone and a worn base tape.

I believe that is an adequate test of hundreds of tires.

Jobst Brandt

On Sep 18, 9:10*am, wrote:
Carl Fogel wrote:
Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. *More goo reduces rolling
resistance:

*http://www.biketechreview.com/forum/...php?f=1&t=2347

Robert Chung mentioned the thread over on RBR.
Carl, you're trolling, considering how often the RR tests have been
discussed here.
Nope, I'm posting a link to a thread about glue on tubulars.
Robert Chung found Kraig's comments plausible.
If you have tests showing anything about glue thickness, let us know.

The whole idea of a thick layer of glue acting as a sponge,
compressively absorbing tubular tire radial motion, is bizarre.

Probably. But he finds a reduction in rolling resistance nonetheless.
Why?

while abrading the base tape. *Any used tubular that was on an
aluminum rim will have grey aluminum debris on the edge of the glue
zone and a worn base tape.

I believe that is an adequate test of hundreds of tires.

That is not a test of rolling resistance.

-pm

On 18 Sep 2008 16:10:22 GMT, wrote:

Carl Fogel wrote:

Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. More goo reduces rolling
resistance:

http://www.biketechreview.com/forum/...php?f=1&t=2347

Robert Chung mentioned the thread over on RBR.

Carl, you're trolling, considering how often the RR tests have been
discussed here.

Nope, I'm posting a link to a thread about glue on tubulars.

Robert Chung found Kraig's comments plausible.

If you have tests showing anything about glue thickness, let us know.

The whole idea of a thick layer of glue acting as a sponge,
compressively absorbing tubular tire radial motion, is bizarre. That
is not where losses occur, but rather in shear of the glue film as the
tire cross section changes from its original unloaded round, to a
flattened oval in the road contact area, and back to round. This is
shown by base tape wear and the reason for using hard glue (tipo
pista) where tire changes are not anticipated and 1/100 of seconds are
at stake in competition.

Tubular tires sit nicely in the semicircular recess of rims when
inflated with no load. When the tire deforms, bulging laterally in
the load affected zone, tension causes tire casings to take a shorter
path across the rim, raising at midpoint out of the "groove" in the
rim. This causes lateral shift on rim side ridges and shears the glue
while abrading the base tape. Any used tubular that was on an
aluminum rim will have grey aluminum debris on the edge of the glue
zone and a worn base tape.

I believe that is an adequate test of hundreds of tires.

Jobst Brandt

Dear Jobst,

Er, what did it _test_ about comparative rolling resistance?

Cheers,

Carl Fogel

arl Fogel wrote:

Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. More goo reduces rolling
resistance:

http://www.biketechreview.com/forum/...php?f=1&t=2347

Robert Chung mentioned the thread over on RBR.

Carl, you're trolling, considering how often the RR tests have been
discussed here.

Nope, I'm posting a link to a thread about glue on tubulars.

Robert Chung found Kraig's comments plausible.

If you have tests showing anything about glue thickness, let us know.

The whole idea of a thick layer of glue acting as a sponge,
compressively absorbing tubular tire radial motion, is bizarre.
That is not where losses occur, but rather in shear of the glue
film as the tire cross section changes from its original unloaded
round, to a flattened oval in the road contact area, and back to
round. This is shown by base tape wear and the reason for using
hard glue (tipo pista) where tire changes are not anticipated and
1/100 of seconds are at stake in competition.

Tubular tires sit nicely in the semicircular recess of rims when
inflated with no load. When the tire deforms, bulging laterally in
the load affected zone, tension causes tire casings to take a
shorter path across the rim, raising at midpoint out of the
"groove" in the rim. This causes lateral shift on rim side ridges
and shears the glue while abrading the base tape. Any used tubular
that was on an aluminum rim will have grey aluminum debris on the
edge of the glue zone and a worn base tape.

I believe that is an adequate test of hundreds of tires.

Er, what did it _test_ about comparative rolling resistance?

I think you missed the cause of tubular rolling resistance and the use
of hard glue to get rid of that source. Increasing the source does
not get rid of it. Even if the glue were to gel and become latex
rubber, it would still have more RR because rubber is hysteretic and
its flexing increases with volume in this application.

In contrast, where are the measured RR values for this report and how
was the data taken. I explained how tubular tires squirm on rims and
what the result is. If you have used tubulars with other than shellac
to bond them to the rim, you have the evidence of how these tires,
using road glue (pressure sensitive adhesive), squirm. It takes an
act of faith to believe that more high viscosity adhesive can reduce
these losses.

Jobst Brandt

On 18 Set, 21:57, wrote:
arl Fogel wrote:
Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. *More goo reduces rolling
resistance:
*It
takes an
act of faith to believe that more high viscosity adhesive can reduce
these losses.

Let me venture onto a comment (without having read the references
quoted by the previous posters).

'More goo' or 'more adhesive' really meaning nothing, they being too
vague from a quantative point of view.
Evidently, little may be too little whereas much may be too much.
And it's kind of hard to quantify these qualifications, especially
without knowing what the rim is like, nor how rough the inside of the
tube is.
So, you got to rely on feel, I guess. Which is what all the mechanics
I have watched do, by all means.

Sergio
Pisa

On 18 Sep 2008 19:57:10 GMT, wrote:

arl Fogel wrote:

Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. More goo reduces rolling
resistance:

http://www.biketechreview.com/forum/...php?f=1&t=2347

Robert Chung mentioned the thread over on RBR.

Carl, you're trolling, considering how often the RR tests have been
discussed here.

Nope, I'm posting a link to a thread about glue on tubulars.

Robert Chung found Kraig's comments plausible.

If you have tests showing anything about glue thickness, let us know.

The whole idea of a thick layer of glue acting as a sponge,
compressively absorbing tubular tire radial motion, is bizarre.
That is not where losses occur, but rather in shear of the glue
film as the tire cross section changes from its original unloaded
round, to a flattened oval in the road contact area, and back to
round. This is shown by base tape wear and the reason for using
hard glue (tipo pista) where tire changes are not anticipated and
1/100 of seconds are at stake in competition.

Tubular tires sit nicely in the semicircular recess of rims when
inflated with no load. When the tire deforms, bulging laterally in
the load affected zone, tension causes tire casings to take a
shorter path across the rim, raising at midpoint out of the
"groove" in the rim. This causes lateral shift on rim side ridges
and shears the glue while abrading the base tape. Any used tubular
that was on an aluminum rim will have grey aluminum debris on the
edge of the glue zone and a worn base tape.

I believe that is an adequate test of hundreds of tires.

Er, what did it _test_ about comparative rolling resistance?

I think you missed the cause of tubular rolling resistance and the use
of hard glue to get rid of that source. Increasing the source does
not get rid of it. Even if the glue were to gel and become latex
rubber, it would still have more RR because rubber is hysteretic and
its flexing increases with volume in this application.

In contrast, where are the measured RR values for this report and how
was the data taken. I explained how tubular tires squirm on rims and
what the result is. If you have used tubulars with other than shellac
to bond them to the rim, you have the evidence of how these tires,
using road glue (pressure sensitive adhesive), squirm. It takes an
act of faith to believe that more high viscosity adhesive can reduce
these losses.

Jobst Brandt

Dear Jobst,

I think you missed the fact that the subject is the results of tests.

It takes an act of faith to insist that the tests must be wrong.

Feel free to produce some tests showing the effect of thicker and
thinner layers of glue on rolling resistance.

Cheers,

Carl Fogel

On Thu, 18 Sep 2008 13:35:36 -0700 (PDT), sergio
wrote:

On 18 Set, 21:57, wrote:
arl Fogel wrote:
Here's a thread for those who paste tubular tires to their rims with
frog snot, as Chalo once put it. *More goo reduces rolling
resistance:
*It
takes an
act of faith to believe that more high viscosity adhesive can reduce
these losses.

Let me venture onto a comment (without having read the references
quoted by the previous posters).

'More goo' or 'more adhesive' really meaning nothing, they being too
vague from a quantative point of view.
Evidently, little may be too little whereas much may be too much.
And it's kind of hard to quantify these qualifications, especially
without knowing what the rim is like, nor how rough the inside of the
tube is.
So, you got to rely on feel, I guess. Which is what all the mechanics
I have watched do, by all means.

Sergio
Pisa

Dear Sergio,

The thread goes into some detail about how many coats and tubes of
glue were used. More goo does indeed seem to be more goo.

Cheers,

Carl Fogel