question about tubulars

On Oct 24, 1:42 pm, Dan Connelly
wrote:
Qui si parla Campagnolo-www.vecchios.comwrote:



Minimally measurable differences in rolling resistance is much the
same thing. BFD

Fred

some will argue that 1/4 watt IS significant but it is in the middle
of BFD...

The difference between the best tubulars and the best clinchers is on the order 5 watts at 50 kph.

Rolling resistance is typically 10% of power. So a 20% difference in Crr is 2% of power. If your bike weighs 2% more of total weight, that's 1.6 kg or so. How many would buy a frame weighing 2.6 kg instead of 1.0kg?

Dan

Your example would only make sense IF changes in the weight of the
bike affected the total power requirements along the same order of
magnitude as changes in rolling resistance. Except for moderately
steep climbs, weight isn't that big a deal, marketing hype
notwithstanding.

In article ,
"Mike Jacoubowsky" wrote:

The best thing about clinchers is that once you have repaired the flat
or changed the tube and reinflated it you are set just like you were
at the beginning of your ride and you do *NOT* have to *WORRY* about
cornering. This means you can ride the same way as you have been
unlike the in-the-field-changed tubular where you need to be very
careful in cornering and braking lest the tyre roll off the rim.

Well, maybe yes, maybe no. For you & I, maybe yes. There's a good number of
people who don't bother (or can't figure out) with the required detective
work to figure out what caused their flat in the first place. So they put in
a new tube and have another flat down the road. And then possibly another.
Can't tell you how many people come into the shop complaining that "This is
the 4th flat I've had on this wheel in two days"...

In the past, when I was commuting I'd carry a spare tire as well as tubes so I
could swap the whole mess out and save some time. Then I'd find the thing that had
caused the puncture later at work (or home). Sometimes it isn't that easy: a couple
of weeks ago, I picked up something that caused a super slow leak - I couldn't even
find the puncture on the tube. Eventually I found a tiny piece of wire that stuck
into the inside of the tire by about .005". I fixed it in front of your Cupertino
store - thanks for the air!

--
tanx,
Howard

Faberge eggs are elegant but I prefer Faberge bacon.

remove YOUR SHOES to reply, ok?

Howard Kveck writes:

The best thing about clinchers is that once you have repaired the
flat or changed the tube and re-inflated it you are set just like
you were at the beginning of your ride and you do *NOT* have to
*WORRY* about cornering. This means you can ride the same way as
you have been unlike the in-the-field-changed tubular where you
need to be very careful in cornering and braking lest the tyre
roll off the rim.

Well, maybe yes, maybe no. For you & I, maybe yes. There's a good
number of people who don't bother (or can't figure out) with the
required detective work to figure out what caused their flat in the
first place. So they put in a new tube and have another flat down
the road. And then possibly another. Can't tell you how many
people come into the shop complaining that "This is the 4th flat
I've had on this wheel in two days"...

In the past, when I was commuting I'd carry a spare tire as well as
tubes so I could swap the whole mess out and save some time. Then
I'd find the thing that had caused the puncture later at work (or
home). Sometimes it isn't that easy: a couple of weeks ago, I
picked up something that caused a super slow leak - I couldn't even
find the puncture on the tube. Eventually I found a tiny piece of
wire that stuck into the inside of the tire by about .005". I fixed
it in front of your Cupertino store - thanks for the air!

The fear of rolling a tubular tire, especially a used one, seems to
arise for rims that have ancient glue, tired without any glue and for
reasonably tacky spares that are not used in descending. I say this
because in the many years of riding tubulars in the Santa Cruz
mountains no one rolled a tire although we often had to change a tire
on rough roads for snake bites.

On one of these rides, a rider changed a tire and the replacement had
not seen service so long that it barely had any useful glue. We rode
down the local steepest and most curvy ten mile long descent, Page
Mill Road... and we hurried. When we got home, we pulled off the
spare and discovered that it was essentially not glued. It had
advanced some from braking, piling up against the valve stem.

I was glad it wasn't my bicycle, but it assured me that rolling a tire
required some misstep, like a side slip. It was at that time that I
analyzed how far the center of contact pressure of a tire moves from
center with lean angle on a 25mm cross section tire. Descending roads
that require continuous braking, rims get hot enough for all the glue
to get soft and the tire to creep enough to bulge at the stem and
ultimately to cause a flat by ripping the stem from the inner tube.

Locally, Hicks Road can do that task and both there and on Metcalf
road, riders crashed fatally when their tire came off or flatted. The
police, being unaware of the problem, attributed the crash to excess
speed in a turn... there being no significant turns in either road.
On these roads, in the days of tubulars, riders often had their front
tire lift off in a large arc at the bottom of the grade with strings
of glue spanning the gap. On lesser grades, turning the front wheel
around so the tire would creep back to normal, was a common operation.

I rode down Hicks road last weekend on clinchers and was careful to
use both brakes equally and sparingly going as fast as practical so
more energy went into wind drag while rim cooling was maximized.

I don't want to ride no more steenkin tubulars. I did that far too
long.

Jobst Brandt

Howard Kveck wrote:
In article ,
"Mike Jacoubowsky" wrote:

The best thing about clinchers is that once you have repaired the flat
or changed the tube and reinflated it you are set just like you were
at the beginning of your ride and you do *NOT* have to *WORRY* about
cornering. This means you can ride the same way as you have been
unlike the in-the-field-changed tubular where you need to be very
careful in cornering and braking lest the tyre roll off the rim.
Well, maybe yes, maybe no. For you & I, maybe yes. There's a good number of
people who don't bother (or can't figure out) with the required detective
work to figure out what caused their flat in the first place. So they put in
a new tube and have another flat down the road. And then possibly another.
Can't tell you how many people come into the shop complaining that "This is
the 4th flat I've had on this wheel in two days"...

In the past, when I was commuting I'd carry a spare tire as well as tubes so I
could swap the whole mess out and save some time. Then I'd find the thing that had
caused the puncture later at work (or home). Sometimes it isn't that easy: a couple
of weeks ago, I picked up something that caused a super slow leak - I couldn't even
find the puncture on the tube. Eventually I found a tiny piece of wire that stuck
into the inside of the tire by about .005". I fixed it in front of your Cupertino
store - thanks for the air!

Mike J. owns the air in front of his stores?

--
Tom Sherman - Holstein-Friesland Bovinia
Beer - It's not just for breakfast anymore!

On Oct 24, 1:42 pm, Dan Connelly
wrote:
Qui si parla Campagnolo-www.vecchios.comwrote:



Minimally measurable differences in rolling resistance is much the
same thing. BFD

Fred

some will argue that 1/4 watt IS significant but it is in the middle
of BFD...

The difference between the best tubulars and the best clinchers is on the order 5 watts at 50 kph.

Rolling resistance is typically 10% of power. So a 20% difference in Crr is 2% of power. If your bike weighs 2% more of total weight, that's 1.6 kg or so. How many would buy a frame weighing 2.6 kg instead of 1.0kg?

Dan

How many riders need to lose that 1.6kg off their arse istead of
fretting and whining about rolling resistence and 5 watts at 50 kph(30
miles per hour, see that a lot don't we?)

It's all lost in the noise when anybody talks about any significant
advantages or disadvantages in the bicycle. If you want to improve
performance, focus on the rider in terms of fitness, bike fit, rider
fat and riding finesse. The bicycle is only the 'vehicle' to cycling
performance, the means to the end. BUT today, buy speed, don't train
and make the 'engine' better....

In article ,
Tom Sherman wrote:

Howard Kveck wrote:
In article ,
"Mike Jacoubowsky" wrote:

The best thing about clinchers is that once you have repaired the flat
or changed the tube and reinflated it you are set just like you were
at the beginning of your ride and you do *NOT* have to *WORRY* about
cornering. This means you can ride the same way as you have been
unlike the in-the-field-changed tubular where you need to be very
careful in cornering and braking lest the tyre roll off the rim.
Well, maybe yes, maybe no. For you & I, maybe yes. There's a good number
of
people who don't bother (or can't figure out) with the required detective
work to figure out what caused their flat in the first place. So they put
in
a new tube and have another flat down the road. And then possibly another.
Can't tell you how many people come into the shop complaining that "This
is
the 4th flat I've had on this wheel in two days"...

In the past, when I was commuting I'd carry a spare tire as well as
tubes so I
could swap the whole mess out and save some time. Then I'd find the thing
that had
caused the puncture later at work (or home). Sometimes it isn't that easy:
a couple
of weeks ago, I picked up something that caused a super slow leak - I
couldn't even
find the puncture on the tube. Eventually I found a tiny piece of wire that
stuck
into the inside of the tire by about .005". I fixed it in front of your
Cupertino
store - thanks for the air!

Mike J. owns the air in front of his stores?

He's a business titan, let me tell you.

--
tanx,
Howard

Faberge eggs are elegant but I prefer Faberge bacon.

remove YOUR SHOES to reply, ok?

"Qui si parla Campagnolo-www.vecchios.com" wrote in
message oups.com...

How many riders need to lose that 1.6kg off their arse istead of
fretting and whining about rolling resistence and 5 watts at 50 kph(30
miles per hour, see that a lot don't we?)

It's all lost in the noise when anybody talks about any significant
advantages or disadvantages in the bicycle. If you want to improve
performance, focus on the rider in terms of fitness, bike fit, rider
fat and riding finesse. The bicycle is only the 'vehicle' to cycling
performance, the means to the end. BUT today, buy speed, don't train
and make the 'engine' better....


Ideally, I'd agree. But early in the season this year I bought a set of 36
spoke wheels to train on, with the "what doesn't kill you makes you
stronger" mentality. I used them, but I found myself slipping back to a set
of 28 spoke wheels that I felt a little faster on and because of some other
convenience factors. I knew this was "buying speed" and felt a certain sense
of guilt or cheating (if no one but myself), but the pleasure of being able
to go just that small bit faster made me want to ride and train that much
more. I was more excited about the upcoming training with the 28s than I was
with the 36s. Having transitioned from a full time rider to an after work,
squeeze it in when you can rider, for me that is an appreciable reason (if
not justifiable) to "buy speed". And yes, I still need to lose that 1.6 kg
off my arse.

Howard Kveck wrote:
I fixed it in front of your Cupertino store - thanks for the air!

Tom Sherman wrote:
Mike J. owns the air in front of his stores?

Howard Kveck wrote:
He's a business titan, let me tell you.

Lucky he's not from Seattle or he'd try to patent the air.

On Oct 25, 8:22 am, Donald Munro wrote:
Howard Kveck wrote:
I fixed it in front of your Cupertino store - thanks for the air!
Tom Sherman wrote:
Mike J. owns the air in front of his stores?
Howard Kveck wrote:
He's a business titan, let me tell you.

Lucky he's not from Seattle or he'd try to patent the air.

Or bundle it with the breathing system, BS, and say that the two were
inseparable. Open source air!

R

Scott wrote:
On Oct 24, 1:42 pm, Dan Connelly
wrote:
Qui si parla Campagnolo-www.vecchios.comwrote:



Minimally measurable differences in rolling resistance is much the
same thing. BFD
Fred
some will argue that 1/4 watt IS significant but it is in the middle
of BFD...
The difference between the best tubulars and the best clinchers is on the order 5 watts at 50 kph.

Rolling resistance is typically 10% of power. So a 20% difference in Crr is 2% of power. If your bike weighs 2% more of total weight, that's 1.6 kg or so. How many would buy a frame weighing 2.6 kg instead of 1.0kg?

Dan

Your example would only make sense IF changes in the weight of the
bike affected the total power requirements along the same order of
magnitude as changes in rolling resistance. Except for moderately
steep climbs, weight isn't that big a deal, marketing hype
notwithstanding.


Exactly correct. But that assumption was sufficient to make my point. The reality is a 20% change in rolling resistance is comparable to much more than a 1.6 kg difference in mass.

Dan