tires, the wider the better

In article <[email hidden]>,

Quoted message said:

1896:

"The ...
sensation of floating along in the air with a delightful ease never
dreamed of...."

Yeah. That's it! That's what I've been looking for since high school.
I'll bet I would get it back if I could drop those 35 lbs I've added to
my 6'-2" frame in the intervening 35 years and get back to 160.

I used to float through the air during cross country season too. Now
the earth shakes.

Dan

On 2007-10-04, [email hidden] <[email hidden]> wrote:
[...]

Quoted message said:

"It is not a matter of friction by contact with the ground, for that
being of the rolling type, amounts to practically nothing, but it
depends on the loss of power in compressing the tire. On a two-inch
tire the rider of average weight causes very little compression of the
tire tread. The tire has a great bearing surface. Take half an inch
from the diameter of the tube, however, and it rolls along a constant
indentation and release result. Here the power is lost and hence the
conclusion."

c.f. more recent remarks by Schwalbe, that still "generate skepticism":

http://www.schwalbe.co.uk/pdf/techinfo.pdf

Small diameter tires have a higher rolling resistance at the same
tire pressure, because tire deformation is proportionally more
important, in other words the tire is “less round”.

Wider tires roll better than narrow ones. This assertion generally
generates skepticism, nevertheless at the same tire pressure a
narrow tire deflects more and so deforms more.

Ben C said:

On 2007-10-04, [email hidden] <[email hidden]> wrote:
[...]

Quoted message said:

"It is not a matter of friction by contact with the ground, for that
being of the rolling type, amounts to practically nothing, but it
depends on the loss of power in compressing the tire. On a two-inch
tire the rider of average weight causes very little compression of the
tire tread. The tire has a great bearing surface. Take half an inch
from the diameter of the tube, however, and it rolls along a constant
indentation and release result. Here the power is lost and hence the
conclusion."

c.f. more recent remarks by Schwalbe, that still "generate skepticism":

http://www.schwalbe.co.uk/pdf/techinfo.pdf

Small diameter tires have a higher rolling resistance at the same
tire pressure, because tire deformation is proportionally more
important, in other words the tire is "less round".

Wider tires roll better than narrow ones. This assertion generally
generates skepticism, nevertheless at the same tire pressure a
narrow tire deflects more and so deforms more.

If we take deformation out of the equation, at what speed would a 23mm
tire start out performing a 60mm tire due to air resistance?

tiborg said:

Ben C said:

On 2007-10-04, [email hidden] <[email hidden]> wrote:
[...]

Quoted message said:

"It is not a matter of friction by contact with the ground, for that
being of the rolling type, amounts to practically nothing, but it
depends on the loss of power in compressing the tire. On a two-inch
tire the rider of average weight causes very little compression of the
tire tread. The tire has a great bearing surface. Take half an inch
from the diameter of the tube, however, and it rolls along a constant
indentation and release result. Here the power is lost and hence the
conclusion."

c.f. more recent remarks by Schwalbe, that still "generate skepticism":

http://www.schwalbe.co.uk/pdf/techinfo.pdf

Small diameter tires have a higher rolling resistance at the same
tire pressure, because tire deformation is proportionally more
important, in other words the tire is "less round".

Wider tires roll better than narrow ones. This assertion generally
generates skepticism, nevertheless at the same tire pressure a
narrow tire deflects more and so deforms more.

If we take deformation out of the equation, at what speed would a 23mm
tire start out performing a 60mm tire due to air resistance?

Good question. I've no idea but you'd think it couldn't make that
much difference considering how much wider the rider is than 60mm.

Ben C said:

Wider tires roll better than narrow ones. This assertion generally
generates skepticism, nevertheless at the same tire pressure a
narrow tire deflects more and so deforms more.

Mostly irrelevant. Wide tyres run lower pressures than narrow tyres.
"At the same tyre pressure" means at least one tyre is being misused.

Aeek said:

Ben C said:

Wider tires roll better than narrow ones. This assertion generally
generates skepticism, nevertheless at the same tire pressure a
narrow tire deflects more and so deforms more.

Mostly irrelevant. Wide tyres run lower pressures than narrow tyres.
"At the same tyre pressure" means at least one tyre is being misused.

It might be less ambiguous to state:

When the objective is to smooth out road irregularities, a soft and
wide tire is better.

Or conversely:

When comfort is not an objective, a hard and narrow tire is better.

Aeek said:

Ben C said:

Wider tires roll better than narrow ones. This assertion generally
generates skepticism, nevertheless at the same tire pressure a
narrow tire deflects more and so deforms more.

Mostly irrelevant. Wide tyres run lower pressures than narrow tyres.
"At the same tyre pressure" means at least one tyre is being misused.

Yes, although an interesting consequence is that the fat tyre at the
lower pressure might have similar RR to the thin one at higher
pressure-- as well as being more comfortable.

Quoted message said:

Back around 1899, the typical men's bike used a 28" rim, and the
following articles from the free New York Times archive predicted that
riders would be sensible enough to use wider 2-inch tires instead of
the absurdly narrow 1.5 inch tires.

Here are some tire widths mentioned:

a full 2" tire = 51 mm, wave of the comfortable, efficient future
1 & 3/4" tire = 44 mm, predicted improvement
1 & 5/8" tire = 41 mm, foolish current weight-weenie fad
1 & 1/2" tire = 38 mm, no better than a board

1896:

"The general tendency to lightness in all things pertaining to the
construction of bicycles has caused the cycling public partially to
lose sight of the highest advantage to be derived from the use of the
pneumatic tire. When pneumatics were first used, a full two-inch tire
was considered none too large. It was not necessary to pump it to
extreme hardness in order to preserve either the tire or rim of the
wheel, and its wide track and great resiliency imparted to the rider a
sensation of floating along in the air with a delightful ease never
dreamed of in the earlier days of solid tires."

The problem a lot of people have nowadays is that even if they have
wider tires on a bike, the rims are still generally too narrow, and so
they never get the actual feel of a properly-set-up wheel.

Most MTB's come with the silly 1-inch wide rims now (-same as a road
bike!?!?!) when they would do a lot better with 1.5 to 1.75's, but if
you want that on any lower-end bike you usually are left having custom
wheels ordered or built that have "downhill" rims. Yes you can mount Big
Apples on a 1" wide rim but it don't work right--because you have to
keep the tire pressure up around 60-80 PSI to keep it from squirming
around turns, and these tires work best at lower pressures, 25-35 PSI.

Having a hybrid bike that had 1" rims and switching to wheels that have
1.4" rims (while using the same tires) I can say the difference in ride
quality is fairly impressive. The tire inflation is now a third less
than before, road vibration is much decreased yet the bike still handles
well.

Some cruiser bikes out there aren't too bad, with single-wall rims
around 1.25 to 1.5". The mighty Worksman 26"/559 rims are 1.75" (outside
diameter) but won't accommodate rim brakes at all and so are overlooked
by many people.
~

DougC said:

The problem a lot of people have nowadays is that even if they have
wider tires on a bike, the rims are still generally too narrow, and so
they never get the actual feel of a properly-set-up wheel.

Most MTB's come with the silly 1-inch wide rims now (-same as a road
bike!?!?!) when they would do a lot better with 1.5 to 1.75's, but if
you want that on any lower-end bike you usually are left having custom
wheels ordered or built that have "downhill" rims. Yes you can mount Big
Apples on a 1" wide rim but it don't work right--because you have to
keep the tire pressure up around 60-80 PSI to keep it from squirming
around turns, and these tires work best at lower pressures, 25-35 PSI.

Having a hybrid bike that had 1" rims and switching to wheels that have
1.4" rims (while using the same tires) I can say the difference in ride
quality is fairly impressive. The tire inflation is now a third less
than before, road vibration is much decreased yet the bike still handles
well.

Some cruiser bikes out there aren't too bad, with single-wall rims
around 1.25 to 1.5". The mighty Worksman 26"/559 rims are 1.75" (outside
diameter) but won't accommodate rim brakes at all and so are overlooked
by many people.
~

Interesting that you should bring this up since just yesterday I was
considering building a wheel for a Big Apple. For style I wanted a
deep rim like the Deep V, but I couldn't find any that were both wide
and deep. I settled on a DT Swiss FR6.1d, but after reading your
comment, I wonder if this ETRTO 559x25 rim is still to narrow for the
60-559 Big Apple.

The chart on Sheldown's page ( http://sheldonbrown.com/tire-sizing.html
) suggests a 60mm tire on a 25mm rim would be extreme, but he admits
it's a conservative estimate.

DougC said:

Most MTB's come with the silly 1-inch wide rims now (-same as a road
bike!?!?!) when they would do a lot better with 1.5 to 1.75's, but if
you want that on any lower-end bike you usually are left having custom
wheels ordered or built that have "downhill" rims.

I see cheap mtbs on the road all the time, and none of them have rims
remotely as narrow as those on road bikes.

Michael Warner said:

DougC said:

Most MTB's come with the silly 1-inch wide rims now (-same as a road
bike!?!?!) when they would do a lot better with 1.5 to 1.75's, but if
you want that on any lower-end bike you usually are left having custom
wheels ordered or built that have "downhill" rims.

I see cheap mtbs on the road all the time, and none of them have rims
remotely as narrow as those on road bikes.

The very cheap ones have wider rims, but if you buy a Mavic XM117 or 317
or something they are astonishingly narrow. I almost sent mine back
assuming they had sent me the wrong rim.

But it's actually fine with 47mm tyres on it at 60-70psi. Haven't tried
any other combinations.

I have to run but S.Brown offers:
http://www.sheldonbrown.com/tires.html#belts
essential reading and the opinion, apparently well founded
that "Some bicycle tires also have a Kevlar ® belt running under the
tread area, in addition to the normal bias plies. This is intended as
a puncture preventive."
Where my experience unequivocally suggests a Kevlar belt dramatically
decreases rolling resistance and tire contact surface wear thru
keeping the tire ROUND thus reducing the friction bulge at the contact
surface.
This is offered as evidence for a communications problem rather than
gross misunderstandings of what happening.

tiborg said:

DougC said:

The problem a lot of people have nowadays is that even if they have
wider tires on a bike, the rims are still generally too narrow, and so
they never get the actual feel of a properly-set-up wheel.

Interesting that you should bring this up since just yesterday I was
considering building a wheel for a Big Apple. For style I wanted a
deep rim like the Deep V, but I couldn't find any that were both wide
and deep. I settled on a DT Swiss FR6.1d, but after reading your
comment, I wonder if this ETRTO 559x25 rim is still to narrow for the
60-559 Big Apple.

Yay for wide rims! Salsa have some light-ish 26 and 29er rims coming
in 30 and 35mm widths, disc only. I'm betting a 50-559 big apple on a
35mm rim is a better option than a 60 on 25, same volume near as
dammit, prob lighter and much more stable at low pressure

Kinky Cowboy*

*Batteries not included
May contain traces of nuts
Your milage may vary

datakoll said:

Where my experience unequivocally suggests a Kevlar belt dramatically
decreases rolling resistance and tire contact surface wear thru
keeping the tire ROUND thus reducing the friction bulge at the contact
surface.

This is directly opposite to both my experience and my expectation
based on theoretical considerations. Adding a kevlar belt under the
tread makes the tire less flexible and therefore any deformation as it
rolls will absorb more energy. Whether the increased resistance to
flats is worth the added rolling resistance depends on the
application.

Note that this is completely separate from the use of a kevlar *bead*
to save weight and make the tire foldable.

On Fri, 05 Oct 2007 12:09:52 -0700, peter <[email hidden]>

Quoted message said:

datakoll said:

Where my experience unequivocally suggests a Kevlar belt dramatically
decreases rolling resistance and tire contact surface wear thru
keeping the tire ROUND thus reducing the friction bulge at the contact
surface.

This is directly opposite to both my experience and my expectation
based on theoretical considerations. Adding a kevlar belt under the
tread makes the tire less flexible and therefore any deformation as it
rolls will absorb more energy. Whether the increased resistance to
flats is worth the added rolling resistance depends on the
application.

Note that this is completely separate from the use of a kevlar *bead*
to save weight and make the tire foldable.

In automotive use a belted tire has significantly lower rolling
resistance, unless the belt is steel. Fabric belted radials are the
lowest rolling resistance tires available ( according to many sources
re: electric vehicle use) I used rayon belted radials on my EV years
ago.

--
Posted via a free Usenet account from http://www.teranews.com

tiborg said:

Aeek said:

Ben C said:

Wider tires roll better than narrow ones. This assertion generally
generates skepticism, nevertheless at the same tire pressure a
narrow tire deflects more and so deforms more.

Quoted message said:

Mostly irrelevant. Wide tyres run lower pressures than narrow tyres.
"At the same tyre pressure" means at least one tyre is being misused.

It might be less ambiguous to state:

When the objective is to smooth out road irregularities, a soft and
wide tire is better.

Or conversely:

When comfort is not an objective, a hard and narrow tire is better.

Soft and wide is also better on rough roads where pinch flats are a
problem.

Smokey

clare at snyder.on.ca said:

On Fri, 05 Oct 2007 12:09:52 -0700, peter <[email hidden]>

Quoted message said:

On Oct 5, 5:54 am, datakoll <[email hidden]> wrote:

Quoted message said:

Quoted message said:

Where my experience unequivocally suggests a Kevlar belt dramatically
decreases rolling resistance and tire contact surface wear thru
keeping the tire ROUND thus reducing the friction bulge at the contact
surface.

Quoted message said:

This is directly opposite to both my experience and my expectation
based on theoretical considerations. Adding a kevlar belt under the
tread makes the tire less flexible and therefore any deformation as it
rolls will absorb more energy. Whether the increased resistance to
flats is worth the added rolling resistance depends on the
application.

Quoted message said:

Note that this is completely separate from the use of a kevlar *bead*
to save weight and make the tire foldable.

In automotive use a belted tire has significantly lower rolling
resistance, unless the belt is steel. Fabric belted radials are the
lowest rolling resistance tires available ( according to many sources
re: electric vehicle use) I used rayon belted radials on my EV years
ago.

Yes, but the automotive tires differ from bike tires in two
significant aspects. First is that they are radial rather than bias-
ply construction. That makes for more flexible sidewalls and lets the
tread portion of the tire lie flat on the road surface even as the
sidewalls deform at the contact patch. And they have a substantial
tread pattern so decreasing squirm of the tread by using an underlying
belt results in reduced rolling resistance.

OTOH, bicycle tires do not have a wide, flat surface regardless of the
presence of a belt, are of bias-ply construction, and have only a
minimal tread pattern (optimally they should be slicks for minimum
resistance and best traction on hard road surfaces). As a result,
adding a belt for puncture resistance on bicycle tires results in
added rolling resistance if other aspects of the tire construction are
kept constant.