Latex on tubular base tape

On Tue, 02 Aug 2005 16:18:38 -0400, Tom Reingold
wrote:


No, I think max speed is much more relevant than average speed. The pros
cruise at higher speeds than recreational cyclists, but they're not
hitting bumps harder than when a cyclist -- any cyclist -- hits a bump
at 40 mph.



The bump most likely to cause a flat is your hardest bump, which you
make at max speed.

The fact that the pros might -- might -- have more bumps along the way
(due to their higher average speed), doesn't stress the tube at all, so
the likelihood of a flat isn't any higher for them.

Pros, and racers in general, are going to hit more bumps also because
they often can't see the road in front of them -- just riders.

JT

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On 2 Aug 2005 14:37:07 -0700, "41"
wrote:


wrote:


What will we hear next? That the difficulties of
Paris-Roubaix a re greatly exaggerated because grandmothers
and college girls on single-speed bicycles eventually cover
all those cobblestones without flats or damaged wheels?

Have you ever ridden on cobblestones? They are not a great source of
pinch flats clincher or tubular at any human speed, instead a
bone-shaking. Paris-Roubaix riders use 25mm tires and how many
cobblestone roads have you seen with stones sticking up more than one
inch or with a gap between them big enough to drop a 622 tire that
much?

You're also missing the point about average speed. You don't hit bumps
with your average speed you hit them with the speed you happen to be
going at, at that instant. And you don't get pinch flats from repeated
blows, one will suffice and more make no difference. So, any high speed
descent on a bumpy road is as good as anything else for determing
whether clinchers are particularly susceptible to them..

Dear 41,

I think that 2,000 miles at an average speed of 27 mph is
more likely to produce impact flats than 2,000 miles at an
average speed of 15-20 mph.

My reasoning is that you're far more likely to flat when
you're doing 30-35 mph on blocked-off roads on the plains
and hills in a tight peloton through village intersections
than when you're chugging up one side of an Alpine pass at
very low speeds and then descending only the other half at
higher speeds (the same as the Tour riders) with excellent
visibility.

So I expect more impact flats on the non-mountain stages
because of the much longer distances covered at much higher
speeds with poorer visibility and roads as bad or worse than
the Alpine descents.

But I'm willing to learn that I'm wrong. Are the Tour's
downhills notorious for impact flats? I haven't noticed
anyone claiming this--the usual fuss is about fears that hot
rims will melt glues and cause tubulars to roll off. The
flats that I recall seem to be out on the flatter stages. If
I'm mistaken, I expect someone will dig up some articles
showing otherwise.

I'm still baffled by the idea that Jobst going up and down
remote Alpine passes at an average of 15-20 mph is at the
same risk for impact flats as Lance Armstrong going the same
distance at an average of 27 mph overall, including numerous
climbs and descents.

Why would the "bumps" that Lance hit at an average speed of
34 mph on the first day pose no more threat to his tires
than Jobst hitting them at less than 20 mph? Are only bumps,
potholes, and rocks hit while descending passes eligible to
cause impact flats?

Carl Fogel

wrote:


I've no idea if these are the stretches of road in question
or if they're straight enough to allow high speeds, but at
least anyone can look them up.



There are hairpins at the steepest sections. They always slowing me
down. No way I did 60 mph there.

Lou


Dear Lou,

No offense, but were you a Tour-de-France class professional
racer trying to win a race?

Hell no, but I did my best and there was almost no traffic I remember.

I do appreciate your comment, which has far more content
that what I've seen before--lots of hairpins close together
will indeed slow anyone down, even racers. The elevation and
distance profiles don't show that sort of interesting stuff.

Do you have any idea what your top speed was? And which side
of the Galibier (or both) you descended?

http://www.salite.ch/galibier.htm

http://www.salite.ch/galibier2.htm

That's the same side you referring to Carl. The other side is
http://www.salite.ch/galibier1.htm. I descended both sides. On the
descent to the Lauteret I got my maximum speed, about 75-80 km/hr.
Although it's less steep on average than the descent to Valloire there
are, after a couple of hairpins just below the top, long straights were
you can gain speed.


A map would be nice to look at, but I haven't found one yet.

Look at www.viamichelin.com and search for Valloire en choose Valloire
Savoie en pan a little south.

If I seem too skeptical of Jobst's lower-speed claims, it's
partly because I doubt that my daily "descent" that often
reaches 40-50 mph at 5,000 feet on the western edge of the
Great Plains matches what Tour de France riders achieve on
Alpine passes at higher altitudes.

I rarely reach speeds over 80 km/hr in the Alpes and the Dolomites,.
There is always some traffic, hairpins, bad pavement etc. etc. that
slows me down. My maximum speed in this years Maratona dles Dolomiti
(http://www.maratona.it/home.php) was 76.3 km/hr. In that race the roads
are closed for all traffic so I could cut corners and so on. Still only
76.3 km/hr and I was overtaking a lot of people in the descents.


Lou
--
Posted by news://news.nb.nu

Mike Krueger writes:

The last seven Tours de France were won on tubular tires, and the
guy who won never suffered a flat tire during the race.

So what? On most of my trips in the Alps that cover about the same
distance and more climbing than the TdF, I never pump my clincher
tires for the distance. What does that prove other than that the
tubes do not leak down as fast as the Clement Tubulars with latex
tubes that I used to ride on these tours, pumping them up daily.

I'm not getting your point. What do your experiences touring in the
Alps have to do with whether or not Tour De France riders race on
tubulars or clinchers?

No doubt. With suitable editing and commission none of this makes
much sense. The claim was that tubulars would get fewer flats on such
a difficult assignment. My response was that I ride similar courses
that are longer and do more climbing and don't get flats so much so
that I don't pump the tires for the duration of the ride. I thought
you might be able to see the parallel but I guess not in this
contentious exchange. You see what Carl Vogel has made of it?

I have been riding tubulars exclusively for over a decade, and I
have never suffered a pinch flat, even at pressures as low as 90
psi. Prior to that, while riding clinchers, pinch flats were a
common occurrence, even at higher inflation pressures. And latex
inner tubes, the few times that I was foolish enough to buy them,
were the worst. They wouldn't just puncture, they would rip
apart.

What's "as low as 90 psi?" that's a reasonable pressure for road
riding on a 25mm cross section tire, that is unless you are one of the
pseudo racers who would not admit to riding on less than 140psi on
22mm tires or smaller.

I guess you don't get on rough roads or off pavement. Either that
or you don't weigh as much as the average rider.

I weigh 185 lbs, and the roads here are terrible, but, no, I don't
generally ride my road bikes off-road.

I didn't suggest you ride "off-road" but there are many unpaved roads
in the world that are eminently worth riding.

There is little doubt that it is easier to deal with cleaning and
bandaging a clean-shaven wound, than one that is matted with thick
hair. Having smooth legs also facilitates massage.

Running into these old wive's tales now and then is entertaining.
"Matted with thick hair" do you shave your arms and chest too?

Hmmm, 99.99% of the pro peloton also believe the same "old wives'
tales about leg shaving. It must be a good feeling to know that all
the professional cyclists in the world are wrong, and you are right.

They also believed in tying and soldering spokes for 100 years after
the practice lost its purpose... the high wheeled bicycle. Bicycling
is full of religious beliefs, religious in that they are based
entirely on faith.

Jobst Brandt

Carl Fogel writes:

Impact speed is irrelevant minutiae when the subject is impact
flats? Kinetic energy has no effect?

Again, please tell us your average speed for your tour, the one
that led you to write "So what?" when the Tour de France was
mentioned in connection with impact flats. Was your average speed
15 mph? Eighteen?

The average speed, after all, should have a strong relation to the
average speed of impact--unlike the distance or the elevation
change, which were the two details that you mentioned.

No, I think max speed is much more relevant than average speed. The
pros cruise at higher speeds than recreational cyclists, but
they're not hitting bumps harder than when a cyclist -- any cyclist
-- hits a bump at 40 mph.

The bump most likely to cause a flat is your hardest bump, which
you make at max speed.

The fact that the pros might -- might -- have more bumps along the
way (due to their higher average speed), doesn't stress the tube at
all, so the likelihood of a flat isn't any higher for them.

I think that we disagree.

A rider averaging 27 mph for over 2,000 miles should expect more
impact flats than a rider averaging 15 mph, even if both of them
reach the same top speed.

My point was that if there are zero impact flats then 100% more impact
flats is till zero. Sometime I am at a loss to make clear such self
evident logic. That is why I mentioned that on longer trips with more
descending I don't even pump the tires.

My reasoning is that there are plenty of bumps out there that can be
avoided or survived at 15-20 mph, but which will go bang! when hit
at 25-30 mph.

I suppose you could achieve that with a clumsy choice of where and how
fast to ride on a road. The way you say that I get the impression
that your riding is done almost exclusively at the KBD hypothetically.
The following derivation seems to fit that model. You should also
note that downhill speed is not determined on age or profession and
has little to do with what team jersey is worn.

This year, the leading Tour de France riders averaged around 27 mph,
riding for huge prizes and prestige. They zoom along roads blocked
off to other traffic, going through towns and intersections at
speeds well above what ordinary riders can maintain on open roads.
They spend much of their time in a peloton, unable to see much
besides the wheel right in front of them, with little chance to
dodge or react.

From this I take it you only ride alone and not in close proximity of
other riders. Group riding is usually developed early in life when
many of us raced in close packs. It doesn't work the way you envision
it... that the leading rider try to suck followers into pot holes and
gratings.

Jobst hasn't mentioned his average speed this year, but he's
retired, thirty years or forty years older than Lance and the rest
of the Tour, and unlikely to average anywhere near 27 mph. (He may
well average a very respectable 15-20 mph, but closer to 15 mph
would be more likely.) He prefers Alpine passes, not the kind of
much faster foothills and flats riding that characterizes many of
the Tour stages. Obviously, he will avoid many bumps because he's
going slower and doesn't have a peloton blocking his vision.

Kinetic energy increases with the square of velocity. At an average
speed of 15-20 mph, a rider hits bumps with 225 to 400 units of
bang, compared to a rider averaging 25-30 mph and hitting bumps with
625 to 900 units of bang. Hitting things twice as hard on average
should make impact flats more likely.

So I'm at a loss to understand Jobst's "So what?" comment that
equates his private-tour chances of an impact flat on Alpine passes
with a Tour de France rider's chances of an impact while racing over
bad pavement through French villages in a peloton.

Think about it.

What will we hear next? That the difficulties of Paris-Roubaix are
greatly exaggerated because grandmothers and college girls on
single-speed bicycles eventually cover all those cobblestones
without flats or damaged wheels?

Keep trying!

Jobst Brandt

Mike Krueger writes:

The last seven Tours de France were won on tubular tires, and the
guy who won never suffered a flat tire during the race.

So what? On most of my trips in the Alps that cover about the same
distance and more climbing than the TdF, I never pump my clincher
tires for the distance. What does that prove other than that the
tubes do not leak down as fast as the Clement Tubulars with latex
tubes that I used to ride on these tours, pumping them up daily.

I'm not getting your point. What do your experiences touring in the
Alps have to do with whether or not Tour De France riders race on
tubulars or clinchers?

No doubt. With suitable editing and ommissions none of this makes
much sense. The claim was that tubulars would get fewer flats on such
a difficult assignment. My response was that I ride similar courses
that are longer and do more climbing and don't get flats so much so
that I don't pump the tires for the duration of the ride. I thought
you might be able to see the parallel but I guess not in this
contentious exchange. You see what Carl Vogel has made of it?

I have been riding tubulars exclusively for over a decade, and I
have never suffered a pinch flat, even at pressures as low as 90
psi. Prior to that, while riding clinchers, pinch flats were a
common occurrence, even at higher inflation pressures. And latex
inner tubes, the few times that I was foolish enough to buy them,
were the worst. They wouldn't just puncture, they would rip
apart.

What's "as low as 90 psi?" that's a reasonable pressure for road
riding on a 25mm cross section tire, that is unless you are one of the
pseudo racers who would not admit to riding on less than 140psi on
22mm tires or smaller.

I guess you don't get on rough roads or off pavement. Either that
or you don't weigh as much as the average rider.

I weigh 185 lbs, and the roads here are terrible, but, no, I don't
generally ride my road bikes off-road.

I didn't suggest you ride "off-road" but there are many unpaved roads
in the world that are eminently worth riding.

There is little doubt that it is easier to deal with cleaning and
bandaging a clean-shaven wound, than one that is matted with thick
hair. Having smooth legs also facilitates massage.

Running into these old wive's tales now and then is entertaining.
"Matted with thick hair" do you shave your arms and chest too?

Hmmm, 99.99% of the pro peloton also believe the same "old wives'
tales about leg shaving. It must be a good feeling to know that all
the professional cyclists in the world are wrong, and you are right.

They also believed in tying and soldering spokes for 100 years after
the practice lost its purpose... the high wheeled bicycle. Bicycling
is full of religious beliefs, religious in that they are based
entirely on faith.

Jobst Brandt

"41" wrote in message
oups.com...

wrote:


What will we hear next? That the difficulties of
Paris-Roubaix a re greatly exaggerated because grandmothers
and college girls on single-speed bicycles eventually cover
all those cobblestones without flats or damaged wheels?

Have you ever ridden on cobblestones? They are not a great
source of
pinch flats clincher or tubular at any human speed, instead a
bone-shaking. Paris-Roubaix riders use 25mm tires and how many
cobblestone roads have you seen with stones sticking up more
than one
inch or with a gap between them big enough to drop a 622 tire
that
much?

Apparently, pinch flats were common on the cobbles at the 2003
Paris Roubaix. See http://tinyurl.com/dey24 . -- Jay Beattie.

On Wed, 03 Aug 2005 00:19:07 +0200, Lou Holtman
wrote:

wrote:


I've no idea if these are the stretches of road in question
or if they're straight enough to allow high speeds, but at
least anyone can look them up.



There are hairpins at the steepest sections. They always slowing me
down. No way I did 60 mph there.

Lou


Dear Lou,

No offense, but were you a Tour-de-France class professional
racer trying to win a race?

Hell no, but I did my best and there was almost no traffic I remember.

I do appreciate your comment, which has far more content
that what I've seen before--lots of hairpins close together
will indeed slow anyone down, even racers. The elevation and
distance profiles don't show that sort of interesting stuff.

Do you have any idea what your top speed was? And which side
of the Galibier (or both) you descended?

http://www.salite.ch/galibier.htm

http://www.salite.ch/galibier2.htm

That's the same side you referring to Carl. The other side is
http://www.salite.ch/galibier1.htm. I descended both sides. On the
descent to the Lauteret I got my maximum speed, about 75-80 km/hr.
Although it's less steep on average than the descent to Valloire there
are, after a couple of hairpins just below the top, long straights were
you can gain speed.


A map would be nice to look at, but I haven't found one yet.

Look at www.viamichelin.com and search for Valloire en choose Valloire
Savoie en pan a little south.

If I seem too skeptical of Jobst's lower-speed claims, it's
partly because I doubt that my daily "descent" that often
reaches 40-50 mph at 5,000 feet on the western edge of the
Great Plains matches what Tour de France riders achieve on
Alpine passes at higher altitudes.

I rarely reach speeds over 80 km/hr in the Alpes and the Dolomites,.
There is always some traffic, hairpins, bad pavement etc. etc. that
slows me down. My maximum speed in this years Maratona dles Dolomiti
(http://www.maratona.it/home.php) was 76.3 km/hr. In that race the roads
are closed for all traffic so I could cut corners and so on. Still only
76.3 km/hr and I was overtaking a lot of people in the descents.


Lou

Dear Lou,

Again, no offense intended, but the 147 km long course of
that mass "marathon" event has been won for the last three
years not by any professional, but by an ex-professional,
Emanuele Negrini. His top speed might be interesting.

I may be wrong, but I suspect that the actual pros mentioned
as celebrities on that page are too sporting to enter this
charity event and actually compete.

In any case, it would be surprising if you didn't overtake a
lot of people--the course was closed to other traffic, but
there were 8,690 other riders on the road with you in 2005.

In 2001, according to the last age-table, over half the
7,284 riders were 40 to 78 years old. Less than 10% were
under 30. There were about as many riders 65 and over as
there were riders 20 and under.

I hope that it was as much fun as it sounds, but it may not
be the best indicator of the speeds that pros in the Tour de
France achieve downhill.

Carl Fogel

On Tue, 02 Aug 2005 23:59:17 GMT,
wrote:

Mike Krueger writes:

The last seven Tours de France were won on tubular tires, and the
guy who won never suffered a flat tire during the race.

So what? On most of my trips in the Alps that cover about the same
distance and more climbing than the TdF, I never pump my clincher
tires for the distance. What does that prove other than that the
tubes do not leak down as fast as the Clement Tubulars with latex
tubes that I used to ride on these tours, pumping them up daily.

I'm not getting your point. What do your experiences touring in the
Alps have to do with whether or not Tour De France riders race on
tubulars or clinchers?

No doubt. With suitable editing and commission none of this makes
much sense. The claim was that tubulars would get fewer flats on such
a difficult assignment. My response was that I ride similar courses
that are longer and do more climbing and don't get flats so much so
that I don't pump the tires for the duration of the ride. I thought
you might be able to see the parallel but I guess not in this
contentious exchange. You see what Carl Vogel has made of it?

I have been riding tubulars exclusively for over a decade, and I
have never suffered a pinch flat, even at pressures as low as 90
psi. Prior to that, while riding clinchers, pinch flats were a
common occurrence, even at higher inflation pressures. And latex
inner tubes, the few times that I was foolish enough to buy them,
were the worst. They wouldn't just puncture, they would rip
apart.

What's "as low as 90 psi?" that's a reasonable pressure for road
riding on a 25mm cross section tire, that is unless you are one of the
pseudo racers who would not admit to riding on less than 140psi on
22mm tires or smaller.

I guess you don't get on rough roads or off pavement. Either that
or you don't weigh as much as the average rider.

I weigh 185 lbs, and the roads here are terrible, but, no, I don't
generally ride my road bikes off-road.

I didn't suggest you ride "off-road" but there are many unpaved roads
in the world that are eminently worth riding.

There is little doubt that it is easier to deal with cleaning and
bandaging a clean-shaven wound, than one that is matted with thick
hair. Having smooth legs also facilitates massage.

Running into these old wive's tales now and then is entertaining.
"Matted with thick hair" do you shave your arms and chest too?

Hmmm, 99.99% of the pro peloton also believe the same "old wives'
tales about leg shaving. It must be a good feeling to know that all
the professional cyclists in the world are wrong, and you are right.

They also believed in tying and soldering spokes for 100 years after
the practice lost its purpose... the high wheeled bicycle. Bicycling
is full of religious beliefs, religious in that they are based
entirely on faith.

Jobst Brandt

Dear Jobst,

I'll continue to make the comment that I'm baffled by your
claim to be as prone to impact flats as Tour de France
racers because I think that overall you go rather more
slowly, have much better visibility, and aren't blasting
through villages and intersections on closed-off roads.

You're the one who contended "So what?" and dismissed the
notion that there might be a significant difference between
your tour and Lance Armstrong's because you ride the same
distance and climb roughly the same elevations.

Carl Fogel

On Wed, 03 Aug 2005 00:13:49 GMT,
wrote:

From this I take it you only ride alone and not in close proximity of
other riders. Group riding is usually developed early in life when
many of us raced in close packs. It doesn't work the way you envision
it... that the leading rider try to suck followers into pot holes and
gratings.


There is a big difference between riding with four or ten other people
and riding in a group of 100 or more where the 100 are either filling
the width of the road or are so strung out that most everyone is
hurting and mainly just looking ahead and not at the road.

A tire I was riding went flat a couple weeks ago 20 seconds after I
rode through a large pothole in a race. There is very little chance I
would have hit such a hole in a small group, but as it was I was in a
fair bit of pain and there were riders all around me. Racing is not
the same as recreational riding. And this was just a regional event
with perhaps 60 riders.

JT

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