Lateral wheel deflection test

Roues artisanales finally finished their testing on lateral deflection
of wheels. Some of you might find it interesting.

http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for lateral
stiffness to be interesting but am curious as to what people might
have to say about the accuracy of the testing. They seem to have
taken a somewhat unique approach to how they came up with their
lateral stiffness data.

Steve

Steve Sauter wrote:

Roues artisanales finally finished their testing on lateral
deflection of wheels. Some of you might find it interesting.

http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for lateral
stiffness to be interesting but am curious as to what people might
have to say about the accuracy of the testing. They seem to have
taken a somewhat unique approach to how they came up with their
lateral stiffness data.

# Coming back to our frontal stiffness test, the wheel is fixed by its
# axle, then crushed. The force applied is determined by software
# which records deformation at the same time.

# The wheels deform very little because of several parameters playing
# an important role in the vertical deformation. The rim height and
# its high frontal stiffness are not really prone to deform easily.
# Shallower rims obviously deform more easily than deep rims because
# they are not as stiff. The spokes also play a role: their number,
# crossing pattern, tension and spoke stiffness (material, cross
# section) all have an influence on overall vertical stiffness of the
# wheel. A low cross section spoke with low spoke tension will deform
# or lose its stiffness quicker than a high cross section and high
# tensioned spoke. The hub plays a role too, but its influence will
# be smaller than the two first.

I find the reporting style anecdotal and qualitative rather than
quantitative, terms not being defined or causes not identified.

Using the term "frontal stiffness" is already a problem as I see it.
I think they mean radial stiffness in contrast to lateral stiffness.

In test results reporting doesn't get better by including quality of
tubular tire brands with wheel stiffness. The use of much esoteric
test machinery doesn't help either. In one picture, spokes are
clearly buckled and no longer have structural function. It leaves me
with the subtle feeling that I have been spammed... and advertising
gimmick.

Jobst Brandt

Steve Sauter wrote:

Roues artisanales finally finished their testing on lateral
deflection of wheels. Some of you might find it interesting.

http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for lateral
stiffness to be interesting but am curious as to what people might
have to say about the accuracy of the testing. They seem to have
taken a somewhat unique approach to how they came up with their
lateral stiffness data.

# Coming back to our frontal stiffness test, the wheel is fixed by its
# axle, then crushed. The force applied is determined by software
# which records deformation at the same time.

# The wheels deform very little because of several parameters playing
# an important role in the vertical deformation. The rim height and
# its high frontal stiffness are not really prone to deform easily.
# Shallower rims obviously deform more easily than deep rims because
# they are not as stiff. The spokes also play a role: their number,
# crossing pattern, tension and spoke stiffness (material, cross
# section) all have an influence on overall vertical stiffness of the
# wheel. A low cross section spoke with low spoke tension will deform
# or lose its stiffness quicker than a high cross section and high
# tensioned spoke. The hub plays a role too, but its influence will
# be smaller than the two first.

I find the reporting style anecdotal and qualitative rather than
quantitative, terms not being defined or causes not identified.

Using the term "frontal stiffness" is already a problem as I see it.
I think they mean radial stiffness in contrast to lateral stiffness.

In test results reporting doesn't get better by including quality of
tubular tire brands with wheel stiffness. The use of much esoteric
test machinery doesn't help either. In one picture, spokes are
clearly buckled and no longer have structural function. It leaves me
with the subtle feeling that I have been spammed... by an advertising
gimmick.

Jobst Brandt

On 2008-11-02, wrote:
Steve Sauter wrote:

Roues artisanales finally finished their testing on lateral
deflection of wheels. Some of you might find it interesting.

http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for lateral
stiffness to be interesting but am curious as to what people might
have to say about the accuracy of the testing. They seem to have
taken a somewhat unique approach to how they came up with their
lateral stiffness data.

# Coming back to our frontal stiffness test, the wheel is fixed by its
# axle, then crushed. The force applied is determined by software
# which records deformation at the same time.

# The wheels deform very little because of several parameters playing
# an important role in the vertical deformation. The rim height and
# its high frontal stiffness are not really prone to deform easily.
# Shallower rims obviously deform more easily than deep rims because
# they are not as stiff. The spokes also play a role: their number,
# crossing pattern, tension and spoke stiffness (material, cross
# section) all have an influence on overall vertical stiffness of the
# wheel. A low cross section spoke with low spoke tension will deform
# or lose its stiffness quicker than a high cross section and high
# tensioned spoke. The hub plays a role too, but its influence will
# be smaller than the two first.

I find the reporting style anecdotal and qualitative rather than
quantitative, terms not being defined or causes not identified.

Using the term "frontal stiffness" is already a problem as I see it.
I think they mean radial stiffness in contrast to lateral stiffness.

They do mean radial stiffness.

In test results reporting doesn't get better by including quality of
tubular tire brands with wheel stiffness. The use of much esoteric
test machinery doesn't help either. In one picture, spokes are
clearly buckled and no longer have structural function.

Indeed, and that's why you can see elbows in their stiffness graphs. As
we know rear wheels' lateral stiffness roughly halves when the rim moves
to the right by a few mm.

On 2008-11-02, steve wrote:
Roues artisanales finally finished their testing on lateral deflection
of wheels. Some of you might find it interesting.

http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for lateral
stiffness to be interesting but am curious as to what people might
have to say about the accuracy of the testing. They seem to have
taken a somewhat unique approach to how they came up with their
lateral stiffness data.

It looks fairly similar to the procedure Damon Rinard used:

http://www.sheldonbrown.com/rinard/wheel/index.htm

The main difference is that the Artisanales are using a 20kg load, which
is enough to slacken spokes on some of the wheels. Rinard used an 11.7kg
load.

But their point is that the wheel might see a 20kg lateral load in use
if you weigh =90kg or are strong.

Ben C? wrote:

Roues artisanales finally finished their testing on lateral deflection
of wheels. Some of you might find it interesting.

http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for lateral
stiffness to be interesting but am curious as to what people might
have to say about the accuracy of the testing. They seem to have
taken a somewhat unique approach to how they came up with their
lateral stiffness data.

It looks fairly similar to the procedure Damon Rinard used:

http://www.sheldonbrown.com/rinard/wheel/index.htm

The main difference is that the Artisanales are using a 20kg load,
which is enough to slacken spokes on some of the wheels. Rinard used
an 11.7kg load.

I think Damon's report gets to the point directly and doesn't try to
snow the reader with jargon.

But their point is that the wheel might see a 20kg lateral load in
use if you weigh =90kg or are strong.

In that respect, I think Artisanales ought to demonstrate where such
loads occur on a road bicycle. Jumping over sticks and stones on
MTB's causes all sorts of wheel failures that are practically
impossible to standardize and characterize in tests.

Jobst Brandt

On 2008-11-03, wrote:
Ben C? wrote:

Roues artisanales finally finished their testing on lateral deflection
of wheels. Some of you might find it interesting.

http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for lateral
stiffness to be interesting but am curious as to what people might
have to say about the accuracy of the testing. They seem to have
taken a somewhat unique approach to how they came up with their
lateral stiffness data.

It looks fairly similar to the procedure Damon Rinard used:

http://www.sheldonbrown.com/rinard/wheel/index.htm

The main difference is that the Artisanales are using a 20kg load,
which is enough to slacken spokes on some of the wheels. Rinard used
an 11.7kg load.

I think Damon's report gets to the point directly and doesn't try to
snow the reader with jargon.

The Artisanales sound to me like they're French and English is not their
first language, so you have to make some allowances.

Damon's report is certainly much better written.

But their point is that the wheel might see a 20kg lateral load in
use if you weigh =90kg or are strong.

In that respect, I think Artisanales ought to demonstrate where such
loads occur on a road bicycle. Jumping over sticks and stones on
MTB's causes all sorts of wheel failures that are practically
impossible to standardize and characterize in tests.

See sections 2a and 2b in that article. There's a diagram showing where
the lateral force comes from. They're talking about pedalling hard while
out of the saddle with the bicycle leaned over to one side.

I'm not sure I understand this comment though:

"Beside this, when the rider pushes the pedals, the torque
transmited through the spokes deforms the wheel because of the
bracing angles creating a lateral component: even when sitting in
the saddle, the rear wheels moves between the brake pads when a
rider stomps on the pedals"

Since the freewheel is connected to the right-hand flange and not to the
centre line, pushing the pedals will cause the wheel to want to rotate
about its vertical axis as well as about its horizontal one. I think
that must be what they're talking about.

One of the wheels they're investigating (the Lew) does have the flange
on the centreline. They describe that wheel as having "no tension" but
it also has spokes that buckle in compression. They did find it the
least stiff radially. Kind of surprising it works at all.

On Nov 3, 3:41*am, Ben C wrote:
On 2008-11-03, wrote:





Ben C? wrote:

Roues artisanales finally finished their testing on lateral deflection
of wheels. Some of you might find it interesting.

*http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for lateral
stiffness to be interesting but am curious as to what people might
have to say about the accuracy of the testing. *They seem to have
taken a somewhat unique approach to how they came up with their
lateral stiffness data.

It looks fairly similar to the procedure Damon Rinard used:

*http://www.sheldonbrown.com/rinard/wheel/index.htm

The main difference is that the Artisanales are using a 20kg load,
which is enough to slacken spokes on some of the wheels. Rinard used
an 11.7kg load.

I think Damon's report gets to the point directly and doesn't try to
snow the reader with jargon.

The Artisanales sound to me like they're French and English is not their
first language, so you have to make some allowances.

Damon's report is certainly much better written.

But their point is that the wheel might see a 20kg lateral load in
use if you weigh =90kg or are strong.

In that respect, I think Artisanales ought to demonstrate where such
loads occur on a road bicycle. *Jumping over sticks and stones on
MTB's causes all sorts of wheel failures that are practically
impossible to standardize and characterize in tests.

See sections 2a and 2b in that article. There's a diagram showing where
the lateral force comes from. They're talking about pedalling hard while
out of the saddle with the bicycle leaned over to one side.

I'm not sure I understand this comment though:

* * "Beside this, when the rider pushes the pedals, the torque
* * transmited through the spokes deforms the wheel because of the
* * bracing angles creating a lateral component: even when sitting in
* * the saddle, the rear wheels moves between the brake pads when a
* * rider stomps on the pedals"

Since the freewheel is connected to the right-hand flange and not to the
centre line, pushing the pedals will cause the wheel to want to rotate
about its vertical axis as well as about its horizontal one. I think
that must be what they're talking about.

One of the wheels they're investigating (the Lew) does have the flange
on the centreline. They describe that wheel as having "no tension" but
it also has spokes that buckle in compression. They did find it the
least stiff radially. Kind of surprising it works at all.- Hide quoted text -

- Show quoted text -

I think you are right about the wheel moving in the horizontal axis
from torque. One thing I found interesting was their findings on how
much a wheel will deflect at the brake based on rim profile and spoke
count.
The Lew wheels from what I have heard are pretty bad. They tend to
break spokes frequently. Who would have thought that a thin bladed
spoke would have problems with deflection and breaking. I personally
have had lots of problems with their rims cracking while biulding.
Ben this is a bit OT but using the equation you gave me in the last
thread would you say that it is possible for chains to see forces of
1000lbs?

Steve

On 2008-11-03, steve wrote:
On Nov 3, 3:41*am, Ben C wrote:
On 2008-11-03, wrote:





Ben C? wrote:

Roues artisanales finally finished their testing on lateral deflection
of wheels. Some of you might find it interesting.

*http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for lateral
stiffness to be interesting but am curious as to what people might
have to say about the accuracy of the testing. *They seem to have
taken a somewhat unique approach to how they came up with their
lateral stiffness data.

It looks fairly similar to the procedure Damon Rinard used:

*http://www.sheldonbrown.com/rinard/wheel/index.htm

The main difference is that the Artisanales are using a 20kg load,
which is enough to slacken spokes on some of the wheels. Rinard used
an 11.7kg load.

I think Damon's report gets to the point directly and doesn't try to
snow the reader with jargon.

The Artisanales sound to me like they're French and English is not their
first language, so you have to make some allowances.

Damon's report is certainly much better written.

But their point is that the wheel might see a 20kg lateral load in
use if you weigh =90kg or are strong.

In that respect, I think Artisanales ought to demonstrate where such
loads occur on a road bicycle. *Jumping over sticks and stones on
MTB's causes all sorts of wheel failures that are practically
impossible to standardize and characterize in tests.

See sections 2a and 2b in that article. There's a diagram showing where
the lateral force comes from. They're talking about pedalling hard while
out of the saddle with the bicycle leaned over to one side.

I'm not sure I understand this comment though:

* * "Beside this, when the rider pushes the pedals, the torque
* * transmited through the spokes deforms the wheel because of the
* * bracing angles creating a lateral component: even when sitting in
* * the saddle, the rear wheels moves between the brake pads when a
* * rider stomps on the pedals"

Since the freewheel is connected to the right-hand flange and not to the
centre line, pushing the pedals will cause the wheel to want to rotate
about its vertical axis as well as about its horizontal one. I think
that must be what they're talking about.

One of the wheels they're investigating (the Lew) does have the flange
on the centreline. They describe that wheel as having "no tension" but
it also has spokes that buckle in compression. They did find it the
least stiff radially. Kind of surprising it works at all.- Hide quoted text -

- Show quoted text -

I think you are right about the wheel moving in the horizontal axis
from torque. One thing I found interesting was their findings on how
much a wheel will deflect at the brake based on rim profile and spoke
count.
The Lew wheels from what I have heard are pretty bad. They tend to
break spokes frequently. Who would have thought that a thin bladed
spoke would have problems with deflection and breaking. I personally
have had lots of problems with their rims cracking while biulding.

Ben this is a bit OT but using the equation you gave me in the last
thread would you say that it is possible for chains to see forces of
1000lbs?

To get chain force you need to multiply pedal force by crank length /
chainring radius.

So small chainrings and heavy riders result in the biggest chain forces.

A 24 tooth granny ring ought to be 12 inches in circumference. That's
0.3048m. Dividing by 2*pi gives us a radius of 0.049m.

So a 100kg rider pushing with all his weight on an MTB with a 24 tooth
granny ring is a chain force of:

1000N * (0.17 / 0.049) = 3504N or 788 lbf.

You'd need a 127kg rider putting all his weight on the pedal to see
1000lbf. So possible, but quite an extreme case.

Ben C? wrote:

Roues artisanales finally finished their testing on lateral
deflection of wheels. Some of you might find it interesting.

Â*http://www.rouesartisanales.com/article-23159755.html

They have done numerous tests on different wheels that includes
aerodynamic and inertia testing. I found their testing for
lateral stiffness to be interesting but am curious as to what
people might have to say about the accuracy of the testing.
Â*They seem to have taken a somewhat unique approach to how they
came up with their lateral stiffness data.

It looks fairly similar to the procedure Damon Rinard used:

Â*http://www.sheldonbrown.com/rinard/wheel/index.htm

The main difference is that the Artisanales are using a 20kg
load, which is enough to slacken spokes on some of the wheels.
Rinard used an 11.7kg load.

I think Damon's report gets to the point directly and doesn't try
to snow the reader with jargon.

The Artisanales sound to me like they're French and English is not
their first language, so you have to make some allowances.

Damon's report is certainly much better written.

But their point is that the wheel might see a 20kg lateral load
in use if you weigh =90kg or are strong.

In that respect, I think Artisanales ought to demonstrate where
such loads occur on a road bicycle. Â*Jumping over sticks and
stones on MTB's causes all sorts of wheel failures that are
practically impossible to standardize and characterize in tests.

See sections 2a and 2b in that article. There's a diagram showing
where the lateral force comes from. They're talking about
pedaling hard while out of the saddle with the bicycle leaned
over to one side.

I'm not sure I understand this comment though:

Â* "Beside this, when the rider pushes the pedals, the torque
Â* Â*transmitted through the spokes deforms the wheel because of the
Â* Â*bracing angles creating a lateral component: even when sitting
Â* Â*in the saddle, the rear wheels moves between the brake pads
Â* Â*when a rider stomps on the pedals"

Since the freewheel is connected to the right-hand flange and not
to the centre line, pushing the pedals will cause the wheel to
want to rotate about its vertical axis as well as about its
horizontal one. I think that must be what they're talking about.

One of the wheels they're investigating (the Lew) does have the
flange on the centreline. They describe that wheel as having "no
tension" but it also has spokes that buckle in compression. They
did find it the least stiff radially. Kind of surprising it works
at all.

I think you are right about the wheel moving in the horizontal axis
from torque. One thing I found interesting was their findings on
how much a wheel will deflect at the brake based on rim profile and
spoke count.

The Lew wheels from what I have heard are pretty bad. They tend to
break spokes frequently. Who would have thought that a thin bladed
spoke would have problems with deflection and breaking. I
personally have had lots of problems with their rims cracking while
building.

Ben this is a bit OT but using the equation you gave me in the last
thread would you say that it is possible for chains to see forces
of 1000lbs?

To get chain force you need to multiply pedal force by crank length
/ chainring radius.

So small chainrings and heavy riders result in the biggest chain
forces. A 24 tooth granny ring ought to be 12 inches in
circumference. That's 0.3048m. Dividing by 2*pi gives us a radius
of 0.049m.

So a 100kg rider pushing with all his weight on an MTB with a 24
tooth granny ring is a chain force of:

1000N * (0.17 / 0.049) = 3504N or 788 lbf.

You'd need a 127kg rider putting all his weight on the pedal to see
1000lbf. So possible, but quite an extreme case.

Don't overlook that one can put more than one's weight on a downward
pedal. Pulling up on the other pedal together with force of the arms
can increase pedal force significantly. I often ride trails with
steep section that require, probably half again, my body weight on the
downstroke in my lowest gear (that isn't all that low).

I once rode up Filbert St. steep section (31.5% grade) in a 47-21 gear
and that required lots of pull on the upstroke.

http://www.nationmaster.com/encyclop...(San-Francisco)

Jobst Brandt