Rim failure

On 3/6/2021 4:56 PM, John B. wrote:
On Sat, 06 Mar 2021 11:38:27 -0800, Jeff Liebermann
wrote:

On Fri, 5 Mar 2021 09:32:34 -0800 (PST), Tom Kunich
wrote:

On Thursday, March 4, 2021 at 10:10:07 PM UTC-8, wrote:
On Thu, 4 Mar 2021 21:48:47 -0000 (UTC), News 2021
wrote:
On Thu, 04 Mar 2021 08:49:17 -0800, Tom Kunich scribed:

I'm not really sure about this. Aluminum rims are made in a long single
molding and then rolled into a wheel.

Err, I think you'll find they are an extrusion, cut to length and then
'rolled and joined.
Yep. They start as an extrusion. Here's a bunch of videos that show
the process:
https://www.youtube.com/results?search_query=how+bicycle+rims+are+made

The process is shown starting at 00:32
"Factory Tour: Velocity USA Bicycle Wheels"
https://www.youtube.com/watch?v=22sFAFTmBuU

There is really no difference between an extrusion and a molding.
One is two dimensional and the other three.

Can you show me an example of a casting that is 11 meters long? This
company can make extrusions to 11 meters:
https://aluminiumandalloys.com/the-design-of-aluminium-profiles-and-the-technological-limits-of-the-extrusion-process/
While you're at it, can you provide me an example of a solid casting
that has in included hole or other closed shape that runs the entire
length of the casting? No fair using 3D printing. How is an
extrusion two dimensional, or do you simply ignore that it has length?

What is the Difference Between Extruded Aluminum and Cast Aluminum?
https://www.howardprecision.com/what-is-the-difference-between-extruded-aluminum-and-cast-aluminum/
Extrusion is a process by which aluminum billets are
forced through a die, resulting in a desired cross section.
Whereas, casting is a process in which molten aluminum is
poured into a mold and then allowed to solidify.

I would be greatly amused to see a cast aluminum bicycle wheel. It
probably would have a solid cross section. My guess(tm) is that a
solid cast rim:
https://infolific.com/images/bicycling/bike-rim-cross-section.png
would weigh about 4 to 5 times as much as the rim in the above image.

Well, they make a lot of cast aluminum wheels. My wife's Honda has
them.


But she probably doesn't have _Campagnolo_ aluminum wheels:

https://www.racebikemart.com/uploads...1372106074.jpg

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

On 3/6/2021 6:58 PM, John B. wrote:
On Sat, 06 Mar 2021 15:17:51 -0800, Jeff Liebermann
wrote:

On Sun, 07 Mar 2021 05:56:50 +0700, John B.
wrote:

On Sat, 06 Mar 2021 11:38:27 -0800, Jeff Liebermann
wrote:

On Fri, 5 Mar 2021 09:32:34 -0800 (PST), Tom Kunich
wrote:

On Thursday, March 4, 2021 at 10:10:07 PM UTC-8, wrote:
On Thu, 4 Mar 2021 21:48:47 -0000 (UTC), News 2021
wrote:
On Thu, 04 Mar 2021 08:49:17 -0800, Tom Kunich scribed:

I'm not really sure about this. Aluminum rims are made in a long single
molding and then rolled into a wheel.

Err, I think you'll find they are an extrusion, cut to length and then
'rolled and joined.
Yep. They start as an extrusion. Here's a bunch of videos that show
the process:
https://www.youtube.com/results?search_query=how+bicycle+rims+are+made

The process is shown starting at 00:32
"Factory Tour: Velocity USA Bicycle Wheels"
https://www.youtube.com/watch?v=22sFAFTmBuU

There is really no difference between an extrusion and a molding.
One is two dimensional and the other three.

Can you show me an example of a casting that is 11 meters long? This
company can make extrusions to 11 meters:
https://aluminiumandalloys.com/the-design-of-aluminium-profiles-and-the-technological-limits-of-the-extrusion-process/
While you're at it, can you provide me an example of a solid casting
that has in included hole or other closed shape that runs the entire
length of the casting? No fair using 3D printing. How is an
extrusion two dimensional, or do you simply ignore that it has length?

What is the Difference Between Extruded Aluminum and Cast Aluminum?
https://www.howardprecision.com/what-is-the-difference-between-extruded-aluminum-and-cast-aluminum/
Extrusion is a process by which aluminum billets are
forced through a die, resulting in a desired cross section.
Whereas, casting is a process in which molten aluminum is
poured into a mold and then allowed to solidify.

I would be greatly amused to see a cast aluminum bicycle wheel. It
probably would have a solid cross section. My guess(tm) is that a
solid cast rim:
https://infolific.com/images/bicycling/bike-rim-cross-section.png
would weigh about 4 to 5 times as much as the rim in the above image.

Well, they make a lot of cast aluminum wheels. My wife's Honda has
them.

Methinks more likely forged than cast:
https://www.blackburnwheels.com/forged-wheels-vs-cast-wheels/
However, those are for automobiles, not bicycles. Aluminum castings
and forgings are not normally made with thin walls, as is common in
extrusions. Castings and forgings cannot be easily bent into a circle
as is common in extruded wheels. There would be no need to glue the
ends of the bicycle wheel if it were cast or forged in a single
operation. The extruded wheel has a long hollow cavity along its
length, which greatly reduces its weight, that would be rather
difficult to do with a casting and probably impossible with a single
part forging.

Casting have internal imperfections, such as bubbles and voids.
Forgings can have cracks, but no usually no internal imperfections.

Anyway, no way to either cast or forge a bicycle wheel with a hollow
cavity running around the circumference.

As for forged wheels on common ordinary autos, I wonder. Forging
aluminum seems to require massive presses and expensive dies. I would
assume that casting would be so much cheaper that it would be the
first choice on production autos.

As for casting with the hollow cavity? Certainly it is possible, you
could even cast with spoke holes if you wish :-)
http://www.industrialmetalcastings.c...w_casting.html
https://mobexglobal.com/hollow-castings/
https://www.sciencedirect.com/topics...e/sand-casting

But certainly extruded rim shaped aluminum which is then bent (we call
it "formed") into a circle and the ends connected is a far simpler and
of course cheaper method.


The usual process is thixoform, ramming molten aluminum
alloy material into mold trees under a few tons of pressure
with sprues and runners lust like injection molding. I'm
very familiar with that process in bicycle component
production. After molding the piece is rapid-aged with
thermal cycles and usually Xray inspected but the void rate
is small.

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

On 3/6/2021 8:53 PM, News 2021 wrote:
On Sun, 07 Mar 2021 09:15:34 +0700, John B. scribed:

On Sun, 7 Mar 2021 01:33:18 -0000 (UTC), News 2021
wrote:

On Sun, 07 Mar 2021 07:58:58 +0700, John B. scribed:

On Sat, 06 Mar 2021 15:17:51 -0800, Jeff Liebermann
wrote:

On Sun, 07 Mar 2021 05:56:50 +0700, John B.
wrote:

On Sat, 06 Mar 2021 11:38:27 -0800, Jeff Liebermann

wrote:

On Fri, 5 Mar 2021 09:32:34 -0800 (PST), Tom Kunich
wrote:

On Thursday, March 4, 2021 at 10:10:07 PM UTC-8,
wrote:
On Thu, 4 Mar 2021 21:48:47 -0000 (UTC), News 2021
wrote:
On Thu, 04 Mar 2021 08:49:17 -0800, Tom Kunich scribed:

I'm not really sure about this. Aluminum rims are made in a
long single molding and then rolled into a wheel.

Err, I think you'll find they are an extrusion, cut to length
and then 'rolled and joined.
Yep. They start as an extrusion. Here's a bunch of videos that
show the process:
https://www.youtube.com/results?
search_query=how+bicycle+rims+are+made

The process is shown starting at 00:32 "Factory Tour: Velocity
USA Bicycle Wheels" https://www.youtube.com/watch?v=22sFAFTmBuU

There is really no difference between an extrusion and a molding.
One is two dimensional and the other three.

Can you show me an example of a casting that is 11 meters long?
This company can make extrusions to 11 meters:
https://aluminiumandalloys.com/the-d...nium-profiles-
and-
the-technological-limits-of-the-extrusion-process/
While you're at it, can you provide me an example of a solid casting
that has in included hole or other closed shape that runs the entire
length of the casting? No fair using 3D printing. How is an
extrusion two dimensional, or do you simply ignore that it has
length?

What is the Difference Between Extruded Aluminum and Cast Aluminum?
https://www.howardprecision.com/what...rence-between-
extruded-aluminum-and-cast-aluminum/
Extrusion is a process by which aluminum billets are forced
through a die, resulting in a desired cross section.
Whereas, casting is a process in which molten aluminum is poured
into a mold and then allowed to solidify.

I would be greatly amused to see a cast aluminum bicycle wheel. It
probably would have a solid cross section. My guess(tm) is that a
solid cast rim:
https://infolific.com/images/bicycling/bike-rim-cross-section.png
would weigh about 4 to 5 times as much as the rim in the above
image.

Well, they make a lot of cast aluminum wheels. My wife's Honda has
them.

Methinks more likely forged than cast:
https://www.blackburnwheels.com/forged-wheels-vs-cast-wheels/
However,
those are for automobiles, not bicycles. Aluminum castings and
forgings are not normally made with thin walls, as is common in
extrusions. Castings and forgings cannot be easily bent into a circle
as is common in extruded wheels. There would be no need to glue the
ends of the bicycle wheel if it were cast or forged in a single
operation. The extruded wheel has a long hollow cavity along its
length, which greatly reduces its weight, that would be rather
difficult to do with a casting and probably impossible with a single
part forging.

Casting have internal imperfections, such as bubbles and voids.
Forgings can have cracks, but no usually no internal imperfections.

Anyway, no way to either cast or forge a bicycle wheel with a hollow
cavity running around the circumference.

As for forged wheels on common ordinary autos, I wonder. Forging
aluminum seems to require massive presses and expensive dies.

Are you aware of the modern modelling software that would make the
creation of these dies so much cheaper? They can completely model what
will happen when a dollop of material is pressed in the die. so the
initial development expense is greatly reduced.

I suspect there would be benefits in press forging certain shapes that
you can not do with casting. and there is the speed benefit.

That said, a local auto parts manufacturer always talked in terms of
casting and the problem of getting a producer that could deliver
consistently clean castings.

Yes, but I'm not sure whether software modeling is the answer. After all
calculating how much whatever it takes to fill a mold or die has been
done for (probably) thousands of years.

Aah, I don't think you are. The software will model how the material will
behave in the die or mould or press or whatever you use. It isn't just
about volume of material but how it distributes. In the past, this was
considered a bit of a craft that had to be learned on the job.

The advantage of the software is that you can 'test' the mould, die, etc
without the expensive step of actually building them and testing them.




As for decent castings, again this has been done for many years whether
finding a competent producer is currently a problem or not. As part of
my apprentice program we made patterns and had cast iron castings made
and then machined them and assembled machines like wood planers, bench
grinders, drill presses, and I can't remember (granted possible faulty)
ever seeing a bad casting.

his problem was more the QC and finishing of them.


Both polymer and metal molding processes use highly
sophisticated heating/cooling channels in the dies with fine
time/temperature control of both for that very reason.

My remembrance of an iron foundry was that all their work
was open (ambient STP) gravity casting and, yes as you note,
with very few voids.

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

On Sun, 07 Mar 2021 09:45:21 -0600, AMuzi wrote:

On 3/6/2021 4:56 PM, John B. wrote:
On Sat, 06 Mar 2021 11:38:27 -0800, Jeff Liebermann
wrote:

On Fri, 5 Mar 2021 09:32:34 -0800 (PST), Tom Kunich
wrote:

On Thursday, March 4, 2021 at 10:10:07 PM UTC-8, wrote:
On Thu, 4 Mar 2021 21:48:47 -0000 (UTC), News 2021
wrote:
On Thu, 04 Mar 2021 08:49:17 -0800, Tom Kunich scribed:

I'm not really sure about this. Aluminum rims are made in a long single
molding and then rolled into a wheel.

Err, I think you'll find they are an extrusion, cut to length and then
'rolled and joined.
Yep. They start as an extrusion. Here's a bunch of videos that show
the process:
https://www.youtube.com/results?search_query=how+bicycle+rims+are+made

The process is shown starting at 00:32
"Factory Tour: Velocity USA Bicycle Wheels"
https://www.youtube.com/watch?v=22sFAFTmBuU

There is really no difference between an extrusion and a molding.
One is two dimensional and the other three.

Can you show me an example of a casting that is 11 meters long? This
company can make extrusions to 11 meters:
https://aluminiumandalloys.com/the-design-of-aluminium-profiles-and-the-technological-limits-of-the-extrusion-process/
While you're at it, can you provide me an example of a solid casting
that has in included hole or other closed shape that runs the entire
length of the casting? No fair using 3D printing. How is an
extrusion two dimensional, or do you simply ignore that it has length?

What is the Difference Between Extruded Aluminum and Cast Aluminum?
https://www.howardprecision.com/what-is-the-difference-between-extruded-aluminum-and-cast-aluminum/
Extrusion is a process by which aluminum billets are
forced through a die, resulting in a desired cross section.
Whereas, casting is a process in which molten aluminum is
poured into a mold and then allowed to solidify.

I would be greatly amused to see a cast aluminum bicycle wheel. It
probably would have a solid cross section. My guess(tm) is that a
solid cast rim:
https://infolific.com/images/bicycling/bike-rim-cross-section.png
would weigh about 4 to 5 times as much as the rim in the above image.

Well, they make a lot of cast aluminum wheels. My wife's Honda has
them.


But she probably doesn't have _Campagnolo_ aluminum wheels:

https://www.racebikemart.com/uploads...1372106074.jpg

Italian wheels on a Japanese car? Heresy!
--
Cheers,

John B.

On 3/6/2021 11:38 AM, Jeff Liebermann wrote:
While you're at it, can you provide me an example of a solid casting
that has in included hole or other closed shape that runs the entire
length of the casting?

I expect this would be easy if you extend your foundry into the fourth
dimension. Tom knows about such things.

Mark J.

On Sun, 7 Mar 2021 14:52:16 -0800, "Mark J."
wrote:

On 3/6/2021 11:38 AM, Jeff Liebermann wrote:
While you're at it, can you provide me an example of a solid casting
that has in included hole or other closed shape that runs the entire
length of the casting?

I expect this would be easy if you extend your foundry into the fourth
dimension. Tom knows about such things.

Mark J.

Cast iron pipes :-)
--
Cheers,

John B.

On 3/7/2021 4:52 PM, Mark J. wrote:
On 3/6/2021 11:38 AM, Jeff Liebermann wrote:
While you're at it, can you provide me an example of a
solid casting
that has in included hole or other closed shape that runs
the entire
length of the casting?

I expect this would be easy if you extend your foundry into
the fourth dimension. Tom knows about such things.

Mark J.

It's commonly done for metal castings with sand molds[1]:
https://www.onallcylinders.com/2016/...eads-are-made/

that's not practical for a rim channel:
http://www.yellowjersey.org/photosfr...st/rimpins.jpg

[1] check out the photos on that page - very complex figures
with complex bores and channels.

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

On 3/7/2021 7:41 PM, AMuzi wrote:
On 3/7/2021 4:52 PM, Mark J. wrote:
On 3/6/2021 11:38 AM, Jeff Liebermann wrote:
While you're at it, can you provide me an example of a
solid casting
that has in included hole or other closed shape that runs
the entire
length of the casting?

I expect this would be easy if you extend your foundry into
the fourth dimension.Â* Tom knows about such things.

Mark J.

It's commonly done for metal castings with sand molds[1]:
https://www.onallcylinders.com/2016/...eads-are-made/

that's not practical for a rim channel:
http://www.yellowjersey.org/photosfr...st/rimpins.jpg

[1] check out the photos on that page - very complex figures with
complex bores and channels.

I've been told that 3-d printed cores and molds have allowed some real
advances in casting complexity. Some great possibilities there.


--
- Frank Krygowski

On Sun, 07 Mar 2021 09:42:12 -0600, AMuzi wrote:

On 3/6/2021 1:38 PM, Jeff Liebermann wrote:
I would be greatly amused to see a cast aluminum bicycle wheel. It
probably would have a solid cross section. My guess(tm) is that a
solid cast rim:
https://infolific.com/images/bicycling/bike-rim-cross-section.png
would weigh about 4 to 5 times as much as the rim in the above image.

We sold them new in several brands (including Weinmann!):
https://bmxmuseum.com/forsale/1_5165_lg.jpg

They had a trendy moment in the middle 1970s until nylon
molded wheels displaced them.

Amazing. Ok, I yield and am greatly amused.

However, those are BMX wheels, which are typically 20 inch. I was
thinking of 27 in.

More of the same from Mongoose Motomag:
https://www.ebay.com/itm/174651166761
http://www.vintagemongoose.com/products/motomagwheels.php
Made from aluminum, magnesium, or "alloy". The article says:
I made a handful of magnesium Motomag Ones for Rick Twomey’s
Mongoose BMX team to use in high profile races. They were
extremely light weight.
(...)
The real concern was machining as mag chips and dust will
catch fire.

I couldn't find any credible weight numbers.

One of the photos has a patent number:
Mottled cast iron intended for metallurgical mill rolls
https://patents.google.com/patent/PL236609A1/en
Cast iron? Rolling mill? Poland? Huh?


--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

On 3/14/2021 6:47 PM, Jeff Liebermann wrote:
On Sun, 07 Mar 2021 09:42:12 -0600, AMuzi wrote:

On 3/6/2021 1:38 PM, Jeff Liebermann wrote:
I would be greatly amused to see a cast aluminum bicycle wheel. It
probably would have a solid cross section. My guess(tm) is that a
solid cast rim:
https://infolific.com/images/bicycling/bike-rim-cross-section.png
would weigh about 4 to 5 times as much as the rim in the above image.

We sold them new in several brands (including Weinmann!):
https://bmxmuseum.com/forsale/1_5165_lg.jpg

They had a trendy moment in the middle 1970s until nylon
molded wheels displaced them.

Amazing. Ok, I yield and am greatly amused.

However, those are BMX wheels, which are typically 20 inch. I was
thinking of 27 in.

More of the same from Mongoose Motomag:
https://www.ebay.com/itm/174651166761
http://www.vintagemongoose.com/products/motomagwheels.php
Made from aluminum, magnesium, or "alloy". The article says:
I made a handful of magnesium Motomag Ones for Rick Twomey’s
Mongoose BMX team to use in high profile races. They were
extremely light weight.
(...)
The real concern was machining as mag chips and dust will
catch fire.

I couldn't find any credible weight numbers.

One of the photos has a patent number:
Mottled cast iron intended for metallurgical mill rolls
https://patents.google.com/patent/PL236609A1/en
Cast iron? Rolling mill? Poland? Huh?



"I couldn't find any credible weight numbers."

Right, I would assume that about those boat anchors.

People trying to sell them certainly wouldn't and their
marks, er, customers, likely avoided scales after lifting
them out of the carton.

26-decimal MTB nylon mags had their moment:
http://www.yellowjersey.org/ogkmag.jpg

I agree there don't seem to be any full size cast aluminum
mags for bicycles.


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