Wheel technology

I recently came across an article saying that the writer laced his
rear wheel cross 2 on the drive side and cross 3 on the other side.
and said that this lacing had proved itself over the past ten years of
his riding.

Somehow, without doing any calculations this seemed backward to me and
without giving the subject much thought I think I would have laced the
wheel cross 3 on the drive side and possibly cross 2 on the other
side.

Anyone know anything about this? Good? Bad? Why?
--
cheers,

John B.

On 8/25/2015 7:06 PM, John B. wrote:

Anyone know anything about this? Good? Bad? Why?

It flies in the face of conventional wisdom, and happens to be correct.

The side with more crossings (left) does most of the pulling, and the
highly-stressed drive side does less.

My own touring wheel, not used in quite a few years, is radial right and
3x left, on a Phil Wood high-low flange hub. I had nothing bad to say
about it.

Art

On 8/25/2015 9:06 PM, John B. wrote:


I recently came across an article saying that the writer laced his
rear wheel cross 2 on the drive side and cross 3 on the other side.
and said that this lacing had proved itself over the past ten years of
his riding.

Somehow, without doing any calculations this seemed backward to me and
without giving the subject much thought I think I would have laced the
wheel cross 3 on the drive side and possibly cross 2 on the other
side.

Anyone know anything about this? Good? Bad? Why?
--
cheers,

John B.


Completely depends on the number of spokes. 2x is a good
spoke angle for 28h but not for 40 spokes!

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

"John B." wrote in message
news


I recently came across an article saying that the writer laced his
rear wheel cross 2 on the drive side and cross 3 on the other side.
and said that this lacing had proved itself over the past ten years of
his riding.

Somehow, without doing any calculations this seemed backward to me and
without giving the subject much thought I think I would have laced the
wheel cross 3 on the drive side and possibly cross 2 on the other
side.

Anyone know anything about this? Good? Bad? Why?

The first time I ever became aware of the number of crosses was on the
Sturmey Archer 3-speed + dynamo.

Apparently all the spokes are the same length, but the flange is bigger
around the dynamo - so the spokes cross 3 times on the dynamo side to use up
the length.

On 27/08/15 06:44, Ian Field wrote:

"John B." wrote in message
news


I recently came across an article saying that the writer laced his
rear wheel cross 2 on the drive side and cross 3 on the other side.
and said that this lacing had proved itself over the past ten years of
his riding.

Somehow, without doing any calculations this seemed backward to me and
without giving the subject much thought I think I would have laced the
wheel cross 3 on the drive side and possibly cross 2 on the other
side.

Anyone know anything about this? Good? Bad? Why?

The first time I ever became aware of the number of crosses was on the
Sturmey Archer 3-speed + dynamo.

Apparently all the spokes are the same length, but the flange is bigger
around the dynamo - so the spokes cross 3 times on the dynamo side to
use up the length.

That smacks of manufacturing efficiency over engineering reason. Order
all the same length spokes is more efficient than keeping stock of two
different lengths.

--
JS

On Thu, 27 Aug 2015 10:14:23 +1000, James
wrote:

On 27/08/15 06:44, Ian Field wrote:

"John B." wrote in message
news


I recently came across an article saying that the writer laced his
rear wheel cross 2 on the drive side and cross 3 on the other side.
and said that this lacing had proved itself over the past ten years of
his riding.

Somehow, without doing any calculations this seemed backward to me and
without giving the subject much thought I think I would have laced the
wheel cross 3 on the drive side and possibly cross 2 on the other
side.

Anyone know anything about this? Good? Bad? Why?

The first time I ever became aware of the number of crosses was on the
Sturmey Archer 3-speed + dynamo.

Apparently all the spokes are the same length, but the flange is bigger
around the dynamo - so the spokes cross 3 times on the dynamo side to
use up the length.

That smacks of manufacturing efficiency over engineering reason. Order
all the same length spokes is more efficient than keeping stock of two
different lengths.

I think that you are likely correct. As, after all a cross 3 normally
isn't considered a poorly designed wheel nor is a cross 2, and it does
simplify the logistics.
--
cheers,

John B.

"John B." wrote in message
...
On Thu, 27 Aug 2015 10:14:23 +1000, James
wrote:

On 27/08/15 06:44, Ian Field wrote:

"John B." wrote in message
news

I recently came across an article saying that the writer laced his
rear wheel cross 2 on the drive side and cross 3 on the other side.
and said that this lacing had proved itself over the past ten years of
his riding.

Somehow, without doing any calculations this seemed backward to me and
without giving the subject much thought I think I would have laced the
wheel cross 3 on the drive side and possibly cross 2 on the other
side.

Anyone know anything about this? Good? Bad? Why?

The first time I ever became aware of the number of crosses was on the
Sturmey Archer 3-speed + dynamo.

Apparently all the spokes are the same length, but the flange is bigger
around the dynamo - so the spokes cross 3 times on the dynamo side to
use up the length.

That smacks of manufacturing efficiency over engineering reason. Order
all the same length spokes is more efficient than keeping stock of two
different lengths.

I think that you are likely correct. As, after all a cross 3 normally
isn't considered a poorly designed wheel nor is a cross 2, and it does
simplify the logistics.

There seemed to be an awful lot of over zealous mathematicians about back
then!

On Thu, 27 Aug 2015 17:44:21 +0100, "Ian Field"
wrote:


"John B." wrote in message
.. .
On Thu, 27 Aug 2015 10:14:23 +1000, James
wrote:

On 27/08/15 06:44, Ian Field wrote:

"John B." wrote in message
news

I recently came across an article saying that the writer laced his
rear wheel cross 2 on the drive side and cross 3 on the other side.
and said that this lacing had proved itself over the past ten years of
his riding.

Somehow, without doing any calculations this seemed backward to me and
without giving the subject much thought I think I would have laced the
wheel cross 3 on the drive side and possibly cross 2 on the other
side.

Anyone know anything about this? Good? Bad? Why?

The first time I ever became aware of the number of crosses was on the
Sturmey Archer 3-speed + dynamo.

Apparently all the spokes are the same length, but the flange is bigger
around the dynamo - so the spokes cross 3 times on the dynamo side to
use up the length.

That smacks of manufacturing efficiency over engineering reason. Order
all the same length spokes is more efficient than keeping stock of two
different lengths.

I think that you are likely correct. As, after all a cross 3 normally
isn't considered a poorly designed wheel nor is a cross 2, and it does
simplify the logistics.

There seemed to be an awful lot of over zealous mathematicians about back
then!

True. After all a student at MIT "proved" that a bumble bee cannot
fly. I believe that he used wing area and horse, well bee, power to
calculate the energy available to lift the mass. The Bee can't
possibly produce that much energy. Absolutely Cannot Fly!

Some years later another student undertook the same experiment and
proved, using a different formula, that the bumble bee actually can
fly.
--
cheers,

John B.

On 8/27/2015 10:29 PM, John B. wrote:
After all a student at MIT "proved" that a bumble bee cannot
fly. I believe that he used wing area and horse, well bee, power to
calculate the energy available to lift the mass. The Bee can't
possibly produce that much energy. Absolutely Cannot Fly!

Some years later another student undertook the same experiment and
proved, using a different formula, that the bumble bee actually can
fly.

http://www.snopes.com/science/bumblebees.asp

According to a book I read last year, there's still serious work being
done studying the flight of insects. Given the very small sizes
involved, the very unsteady flow of air, the very short stroke of the
wings, etc. the physics of flapping flight and especially insect flight
are complicated indeed. IIRC, at insect sizes and wing velocities, air
acts much more viscous than it does for our conventional airplanes. The
book I read indicated that they are just beginning to make sense of the
way insect wings rely on unsteady vortex flow reinforcing wing motion,
and vice versa.


--
- Frank Krygowski

On Sat, 29 Aug 2015 19:13:52 -0400, Frank Krygowski
wrote:

On 8/27/2015 10:29 PM, John B. wrote:
After all a student at MIT "proved" that a bumble bee cannot
fly. I believe that he used wing area and horse, well bee, power to
calculate the energy available to lift the mass. The Bee can't
possibly produce that much energy. Absolutely Cannot Fly!

Some years later another student undertook the same experiment and
proved, using a different formula, that the bumble bee actually can
fly.

http://www.snopes.com/science/bumblebees.asp

According to a book I read last year, there's still serious work being
done studying the flight of insects. Given the very small sizes
involved, the very unsteady flow of air, the very short stroke of the
wings, etc. the physics of flapping flight and especially insect flight
are complicated indeed. IIRC, at insect sizes and wing velocities, air
acts much more viscous than it does for our conventional airplanes. The
book I read indicated that they are just beginning to make sense of the
way insect wings rely on unsteady vortex flow reinforcing wing motion,
and vice versa.

I'm not sure That Snopes story is what I read. I definitely remember
that the article I read stated that a group of MIT students had proven
that the bumble bee could fly (Ta! Da!) and part of the article
recounted the story about a previous effort that proved that it
couldn't fly. The article spelled out that the "new" study had used a
"moving wing" theory as opposed to the previous study that had used a
fixed wing theorem.

But as for insect flight think of a house fly cruising along in the
kitchen and he/she/it decides to land on the ceiling. Does the fly do
a half roll? Or a half loop?
--
cheers,

John B.