Cannondale recall

sms wrote:
On 7/28/2019 10:06 AM, Tosspot wrote:
On 27/07/2019 20:19, Frank Krygowski wrote:

snip

The trouble with Rivendell forks is they are still hollow. Can you
imagine? A hole right up the middle! We need to return to the solid
forks of yore.

Frank has it spot on.* If only they'd go through the simple p[process of
turning the fork inside out, moving the hole to the outside where it
would cause less trouble, we wouldn't be having these recalls.

Actually a hollow fork will be stronger than a solid fork.

A hollow tube is stronger than a rod of equal mass (assuming the same
material). As the inside diameter increases the tube becomes stronger.
You can increase the diameter to compensate for a weaker material. This
is why aluminum frame tubes have to be of greater diameter than steel
frame tubes.

Surprised that Frank would not know about this since it is basic physics
and material science.


Yeah, but a solid fork will be stronger than a hollow fork of the same OD.
Surprised that you would not know this since it is basics physics and
material science.

On Sunday, July 28, 2019 at 7:44:15 PM UTC-4, sms wrote:
On 7/28/2019 10:06 AM, Tosspot wrote:
On 27/07/2019 20:19, Frank Krygowski wrote:

snip

The trouble with Rivendell forks is they are still hollow. Can you
imagine? A hole right up the middle! We need to return to the solid
forks of yore.

Frank has it spot on.Â* If only they'd go through the simple p[process of
turning the fork inside out, moving the hole to the outside where it
would cause less trouble, we wouldn't be having these recalls.

Actually a hollow fork will be stronger than a solid fork.

A hollow tube is stronger than a rod of equal mass (assuming the same
material). As the inside diameter increases the tube becomes stronger.
You can increase the diameter to compensate for a weaker material. This
is why aluminum frame tubes have to be of greater diameter than steel
frame tubes.

Surprised that Frank would not know about this since it is basic physics
and material science.

I know more about this than you can possibly know. I also know that your
phrase "of equal mass" was definitely NOT part of what I said. Yes, a solid
fork of equal strength will be heavier than a hollow fork of similar material.
That fact is so blindingly obvious that it mocks a person who attempts to use
it to "prove" better knowledge.

- Frank Krygowski

On Mon, 29 Jul 2019 00:51:41 +0000 (UTC), Ralph Barone
wrote:

sms wrote:
On 7/28/2019 10:06 AM, Tosspot wrote:
On 27/07/2019 20:19, Frank Krygowski wrote:

snip

The trouble with Rivendell forks is they are still hollow. Can you
imagine? A hole right up the middle! We need to return to the solid
forks of yore.

Frank has it spot on.* If only they'd go through the simple p[process of
turning the fork inside out, moving the hole to the outside where it
would cause less trouble, we wouldn't be having these recalls.

Actually a hollow fork will be stronger than a solid fork.

A hollow tube is stronger than a rod of equal mass (assuming the same
material). As the inside diameter increases the tube becomes stronger.
You can increase the diameter to compensate for a weaker material. This
is why aluminum frame tubes have to be of greater diameter than steel
frame tubes.

Surprised that Frank would not know about this since it is basic physics
and material science.


Yeah, but a solid fork will be stronger than a hollow fork of the same OD.
Surprised that you would not know this since it is basics physics and
material science.

Heck, even an ole country boy trying to pry a rock out of the road to
the barn can figger out that a 1 inch crow bar can pry a lot more rock
than a chunk of 1 inch pipe.

But them city boys probably never pried a rock :-)
--
cheers,

John B.

On Sunday, July 28, 2019 at 4:33:50 PM UTC-7, sms wrote:
On 7/28/2019 7:36 AM, jbeattie wrote:
On Saturday, July 27, 2019 at 9:34:12 AM UTC-7, sms wrote:
On 7/27/2019 7:34 AM, jbeattie wrote:

snip

The fact is, we don't know what deaths were or were not caused by carbon fork failures.

We pretty much do. The fork fails, the rider crashes and dies. The death
is attributed to fork failure. Yes, there may have been contributing
factors to the fork failure other than a manufacturing defect and a fork
that never had experienced any trauma may not have broken.

I'll pretend you're being serious.

You're assuming cause and effect. It could have been rider crashes, fork fails and rider dies. Or rider dies, crashes and fork fails.

You wouldn't have hundreds of fork recalls for these cases.

Sure you would. It was a voluntary recall. Cannondale had questions and acted cautiously. Good for them. We don't know the strength of the defect or causation evidence. The only discussion of actual testing indicates that Cannondale and third-parties could not identify a defect. There may be a defect that caused each and every injury or death. We just don't know.

-- Jay Beattie.

On Monday, July 29, 2019 at 1:44:15 AM UTC+2, sms wrote:
On 7/28/2019 10:06 AM, Tosspot wrote:
On 27/07/2019 20:19, Frank Krygowski wrote:

snip

The trouble with Rivendell forks is they are still hollow. Can you
imagine? A hole right up the middle! We need to return to the solid
forks of yore.

Frank has it spot on.Â* If only they'd go through the simple p[process of
turning the fork inside out, moving the hole to the outside where it
would cause less trouble, we wouldn't be having these recalls.

Actually a hollow fork will be stronger than a solid fork.

A hollow tube is stronger than a rod of equal mass (assuming the same
material). As the inside diameter increases the tube becomes stronger.
You can increase the diameter to compensate for a weaker material. This
is why aluminum frame tubes have to be of greater diameter than steel
frame tubes.

Surprised that Frank would not know about this since it is basic physics
and material science.

You mix things up. Strength and stiffness are two different things.

Lou

On Sun, 28 Jul 2019 23:42:13 -0700 (PDT), wrote:

On Monday, July 29, 2019 at 1:44:15 AM UTC+2, sms wrote:
On 7/28/2019 10:06 AM, Tosspot wrote:
On 27/07/2019 20:19, Frank Krygowski wrote:

snip

The trouble with Rivendell forks is they are still hollow. Can you
imagine? A hole right up the middle! We need to return to the solid
forks of yore.

Frank has it spot on.* If only they'd go through the simple p[process of
turning the fork inside out, moving the hole to the outside where it
would cause less trouble, we wouldn't be having these recalls.

Actually a hollow fork will be stronger than a solid fork.

A hollow tube is stronger than a rod of equal mass (assuming the same
material). As the inside diameter increases the tube becomes stronger.
You can increase the diameter to compensate for a weaker material. This
is why aluminum frame tubes have to be of greater diameter than steel
frame tubes.

Surprised that Frank would not know about this since it is basic physics
and material science.

You mix things up. Strength and stiffness are two different things.

Lou

In fact strength is usually defined by how difficult it is to rip
something apart :-)
--
cheers,

John B.

On Saturday, July 27, 2019 at 7:58:49 PM UTC-7, Frank Krygowski wrote:
On Saturday, July 27, 2019 at 8:09:58 PM UTC-4, Tom Kunich wrote:


OK Frank - as an engineer tell us about the weaknesses of solid objects with bending forces on them.

Sure. What do you want to know?

You can look up "Stress = M * c / I" to begin your home study. Let me know what
questions you have.

- Frank Krygowski

Just curious why you didn't want to go into the fact that a solid round will bend before a hollow tube of the same diameter.

On 7/29/2019 9:26 AM, Tom Kunich wrote:
On Saturday, July 27, 2019 at 7:58:49 PM UTC-7, Frank Krygowski wrote:
On Saturday, July 27, 2019 at 8:09:58 PM UTC-4, Tom Kunich wrote:


OK Frank - as an engineer tell us about the weaknesses of solid objects with bending forces on them.

Sure. What do you want to know?

You can look up "Stress = M * c / I" to begin your home study. Let me know what
questions you have.

- Frank Krygowski

Just curious why you didn't want to go into the fact that a solid round will bend before a hollow tube of the same diameter.


That's not true for steel bar vs tube. Else prybars would be
hollow!

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

On Monday, July 29, 2019 at 10:26:26 AM UTC-4, Tom Kunich wrote:
On Saturday, July 27, 2019 at 7:58:49 PM UTC-7, Frank Krygowski wrote:
On Saturday, July 27, 2019 at 8:09:58 PM UTC-4, Tom Kunich wrote:


OK Frank - as an engineer tell us about the weaknesses of solid objects with bending forces on them.

Sure. What do you want to know?

You can look up "Stress = M * c / I" to begin your home study. Let me know what
questions you have.

- Frank Krygowski

Just curious why you didn't want to go into the fact that a solid round will bend before a hollow tube of the same diameter.

sigh Tom, I force myself to not respond to a _lot_ of your mistakes. But
that one gets no pass. If you're talking about the same material in both cases
and all other things being equal, you're simply wrong. You shouldn't need any
science background at all to recognize that it's nonsense.

- Frank Krygowski

On Monday, July 29, 2019 at 7:34:02 AM UTC-7, AMuzi wrote:
On 7/29/2019 9:26 AM, Tom Kunich wrote:
On Saturday, July 27, 2019 at 7:58:49 PM UTC-7, Frank Krygowski wrote:
On Saturday, July 27, 2019 at 8:09:58 PM UTC-4, Tom Kunich wrote:


OK Frank - as an engineer tell us about the weaknesses of solid objects with bending forces on them.

Sure. What do you want to know?

You can look up "Stress = M * c / I" to begin your home study. Let me know what
questions you have.

- Frank Krygowski

Just curious why you didn't want to go into the fact that a solid round will bend before a hollow tube of the same diameter.


That's not true for steel bar vs tube. Else prybars would be
hollow!

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