Half radial spoking and the new Dura-Ace wheels

Bill Lloyd wrote:

Good God Peter, are you still riding 6 speed wheels on a regular basis?

I'll see his 6-speed and raise:

My "Brown" is still running a Regina Oro 6 12-22 freewheel, with a 30
year old Sun Tour Cyclone Rear derailer...and brand new Veloce 10 speed
Ergo brittore (that's made-up Eyetalian for "brifteurs")

Sheldon "http://sheldonbrown.org/brown" Brown
+-----------------------------------------------------------+
| Always listen to the experts. |
| They'll tell you what can't be done, and why. |
| Then do it. --Robert A. Heinlein |
+-----------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Bill Lloyd wrote:
On 2004-07-15 05:48:33 -0700, (Qui si parla
Campagnolo ) said:
You shouldn't be breaking spokes at all.
I have a pair of wheels that are 16 years and probably 10 times the
mileage and they don't break spokes.
Good God Peter, are you still riding 6 speed wheels on a regular basis?

Our tandem's got a 6-speed freewheel on. I plan to replace it, but not
because the wheel breaks spokes.
--
David Damerell Distortion Field!

Bill Lloyd wrote:
On 2004-07-15 05:48:33 -0700, (Qui si parla
Campagnolo ) said:
You shouldn't be breaking spokes at all.
I have a pair of wheels that are 16 years and probably 10 times the
mileage and they don't break spokes.
Good God Peter, are you still riding 6 speed wheels on a regular basis?

Our tandem's got a 6-speed freewheel on. I plan to replace it, but not
because the wheel breaks spokes.
--
David Damerell Distortion Field!

David L. Johnson wrote:
On Wed, 14 Jul 2004 21:14:47 -0700, jim beam wrote:


the only reason it could ever be "wrong" is when the hub is one of those
skinny ones that is subject to relative torsion between the left & right
flanges.


Um, _any_ hub which is half-radial with the right side radial would be
subject to exactly the same relative torsion, skinny or fat.

do the math.
http://physics.uwstout.edu/StatStr/s...n/torse51a.htm
a small diameter tube [a "skinny" hub] will be subject to much more
torsional displacement between flanges than a large diameter tube ["fat"
hub].

The thing
is, in order to be strong enough to not break under such torsion, the hub
has to be fat. I can see no advantage in that. Dumb idea, copied from
Rolf.

David L. Johnson wrote:
On Wed, 14 Jul 2004 21:14:47 -0700, jim beam wrote:


the only reason it could ever be "wrong" is when the hub is one of those
skinny ones that is subject to relative torsion between the left & right
flanges.


Um, _any_ hub which is half-radial with the right side radial would be
subject to exactly the same relative torsion, skinny or fat.

do the math.
http://physics.uwstout.edu/StatStr/s...n/torse51a.htm
a small diameter tube [a "skinny" hub] will be subject to much more
torsional displacement between flanges than a large diameter tube ["fat"
hub].

The thing
is, in order to be strong enough to not break under such torsion, the hub
has to be fat. I can see no advantage in that. Dumb idea, copied from
Rolf.

David L. Johnson wrote:
On Thu, 15 Jul 2004 00:27:17 -0700, John McGraw wrote:


Why them ain't no cracks on the Rolf wheels. Rims can only crack when
they are hard anodized. You do not have to belive me. Just Google this
groups archives on the subject & Jobsts posts in particular ;-). In
reality I am far from convinced that all hard anodizing causes cracks
& that non anodized rims almost never crack, which is what Jobst has
implied for years, sometimes going so far to state that any anodizing
causes rims to crack. John


In fairness to Jobst, who seems to be off somewhere right now (or at
least off on a different thread), saying that hard anodizing causes
cracks is not the same as saying that a non-anodized rim will not crack.
It is certainly true that non-anodized rims can crack, but that takes
nothing away from his observation that anodized rims are more likely to do
so.


unfortunately, that "observation" is flawed. i've examined a number of
cracked anodized rims, and while it is possible for cracked anodizing to
initiate fatigue, it's not been the cause of any of the cracking i've
seen. jobst may have ranted on about it for years but it does not mean
he knew what he was looking at or that he'd done his "analysis" correctly.

fact: anodizing is present on the majority of the rims frequently cited
here as "unanodized".
fact: anodizing protects against more serious flaws that cause premature
failure like pitting & corrosion. that's why it's done.

David L. Johnson wrote:
On Thu, 15 Jul 2004 00:27:17 -0700, John McGraw wrote:


Why them ain't no cracks on the Rolf wheels. Rims can only crack when
they are hard anodized. You do not have to belive me. Just Google this
groups archives on the subject & Jobsts posts in particular ;-). In
reality I am far from convinced that all hard anodizing causes cracks
& that non anodized rims almost never crack, which is what Jobst has
implied for years, sometimes going so far to state that any anodizing
causes rims to crack. John


In fairness to Jobst, who seems to be off somewhere right now (or at
least off on a different thread), saying that hard anodizing causes
cracks is not the same as saying that a non-anodized rim will not crack.
It is certainly true that non-anodized rims can crack, but that takes
nothing away from his observation that anodized rims are more likely to do
so.


unfortunately, that "observation" is flawed. i've examined a number of
cracked anodized rims, and while it is possible for cracked anodizing to
initiate fatigue, it's not been the cause of any of the cracking i've
seen. jobst may have ranted on about it for years but it does not mean
he knew what he was looking at or that he'd done his "analysis" correctly.

fact: anodizing is present on the majority of the rims frequently cited
here as "unanodized".
fact: anodizing protects against more serious flaws that cause premature
failure like pitting & corrosion. that's why it's done.

On Thu, 15 Jul 2004 21:32:36 -0700, jim beam wrote:

David L. Johnson wrote:
On Wed, 14 Jul 2004 21:14:47 -0700, jim beam wrote:


the only reason it could ever be "wrong" is when the hub is one of those
skinny ones that is subject to relative torsion between the left & right
flanges.


Um, _any_ hub which is half-radial with the right side radial would be
subject to exactly the same relative torsion, skinny or fat.

do the math.
http://physics.uwstout.edu/StatStr/s...n/torse51a.htm
a small diameter tube [a "skinny" hub] will be subject to much more
torsional displacement between flanges than a large diameter tube ["fat"
hub].

Silly me. I thought when you said "torsion", you meant torsion, which is
the twisting force involved. Sure, the displacement would be worse with a
skinny shaft. Still using radial spoking on the right side is a dumb
idea, since you then have to worry about said displacement, and use a
fatter (and heavier) hub than you would had you simply put crossed spokes
on the right side.

--

David L. Johnson

__o | As far as the laws of mathematics refer to reality, they are not
_`\(,_ | certain, and as far as they are certain, they do not refer to
(_)/ (_) | reality. -- Albert Einstein

On Thu, 15 Jul 2004 21:32:36 -0700, jim beam wrote:

David L. Johnson wrote:
On Wed, 14 Jul 2004 21:14:47 -0700, jim beam wrote:


the only reason it could ever be "wrong" is when the hub is one of those
skinny ones that is subject to relative torsion between the left & right
flanges.


Um, _any_ hub which is half-radial with the right side radial would be
subject to exactly the same relative torsion, skinny or fat.

do the math.
http://physics.uwstout.edu/StatStr/s...n/torse51a.htm
a small diameter tube [a "skinny" hub] will be subject to much more
torsional displacement between flanges than a large diameter tube ["fat"
hub].

Silly me. I thought when you said "torsion", you meant torsion, which is
the twisting force involved. Sure, the displacement would be worse with a
skinny shaft. Still using radial spoking on the right side is a dumb
idea, since you then have to worry about said displacement, and use a
fatter (and heavier) hub than you would had you simply put crossed spokes
on the right side.

--

David L. Johnson

__o | As far as the laws of mathematics refer to reality, they are not
_`\(,_ | certain, and as far as they are certain, they do not refer to
(_)/ (_) | reality. -- Albert Einstein

In article ,
Sheldon Brown wrote:

Bill Lloyd wrote:

Good God Peter, are you still riding 6 speed wheels on a regular basis?

I'll see his 6-speed and raise:

My "Brown" is still running a Regina Oro 6 12-22 freewheel, with a 30
year old Sun Tour Cyclone Rear derailer...and brand new Veloce 10 speed
Ergo brittore (that's made-up Eyetalian for "brifteurs")

Glad to see you're finally coming around.

I love "u",
--
Ryan Cousineau, http://www.wiredcola.com
President, Fabrizio Mazzoleni Fan Club