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Interesting track crashes



 
 
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  #21  
Old December 29th 18, 03:35 AM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default Interesting track crashes

On 12/28/2018 7:46 PM, Frank Krygowski wrote:
On 12/28/2018 7:35 PM, AMuzi wrote:
On 12/28/2018 6:00 PM, John B. Slocomb wrote:
On Fri, 28 Dec 2018 14:41:12 -0800 (PST),
wrote:

On Wednesday, December 26, 2018 at 4:22:08 PM UTC-8,
John B. Slocomb wrote:
On Wed, 26 Dec 2018 12:02:58 -0800 (PST),
wrote:

On Thursday, November 29, 2018 at 1:25:28 PM UTC-8,
Sir Ridesalot wrote:
An interesting video of track bicycles crashing.
Amazing what happens when a tubular tire comes off
the rim. I was surprised at how long one rider stayed
up - he was okay until the front tire went under his
rear wheel.

I saw bits flying around in some of the crashes but
couldn't make out what those bits were.

https://www.youtube.com/watch?v=tf17hFikqrQ

Cheers

Track tubulars are paper thin so flats from
overheating aren't all that uncommon. My friend who
has turned into a total anti-carbon fiber nut sent me
a video link to a subject he called "carbon fiber rim
exploding under track rider." That isn't what I would
have called it. If you look at it closely it looks
like a track tandem gets a flat in the final sprint
which throws the entire weight of the team unto the
front disk which slowly comes apart as the tire peels
off.

I showed him that foregoing manufacturing errors that
all of the bicycle materials have approximately the
same loaded lifespan. That was sort of surprising to
me since I have a lot of steel bikes and never had a
failure. But I suppose I usually buy them with very
little use and they simply don't have that many miles.

Actually the most common frame material to fail is
aluminum. Come sources say never keep an aluminum
frame for more than 10 years max. And the failures are
highly reminiscent of the Internet pictures of carbon
fiber failures save that the CF bikes usually have
been hit by cars whereas the AL bikes simply fall apart.

Interesting.
Of course Sheldon Brown, that sneaky devil, describes a
study
conducted by EFBe (Engineering for Bikes) which is now,
I believe, one
of the main elements of the DIN 79100 bicycle-testing
standard, which
was published in TOUR magazine of Oct 1997 ( more then
20 years ago)
that demonstrated that two of the three frames that
completed the test
with no failures were welded aluminum frames. Two out
of three... lets
see, that is about 66.666 %, isn't it?

The Christian Bible has a phrase that seems to apply
here (Proverbs
17:28. New International Version)

"Even a fool is thought wise if he keeps silent, and
discerning if he
holds his tongue."

cheers,

John B.

Of course anyone with any training would understand that
this testing meant nothing. While the test itself was
well designed using a single example of each frame
yielded no more information that THAT single example.

But then you're the sort of engineer who would build a
bridge without actually testing the components of it.

I see... first you condemn a test to failure as it tests
only one
example and then you refer to testing bridge components.

Tom, you are a fool. Or do you actually believe that each
component of
a bridge is tested to failure... before it is used?

I worked for a company that specialized in contacting with
international oil companies to build and.or maintain oil
fields in
remote areas and in doing so we built innumerable bridges
and I'm
sorry to inform you that we never tested the components
of any of the
bridges... never. And I can assure you that none of the
bridges ever
fell down.

I might add, that as we were in business for over 20
years, and as oil
companies were still giving us contacts it is patently
obvious that we
knew what we were doing as oil companies don't renew
contacts to
companies that build bridges that fall down.

I keep telling you, "It's better to keep your mouth shut
and appear
stupid than open it and remove all doubt" and you don't
listen.



Indonesia may have some regard for human life and
engineering standards. Not everyone does:

https://am1590theanswer.com/news/nat...10-years-later



"...federal funding has been 'pretty stagnant,' but about 20
states raised taxes to increase their bridge spending."

Where are the "No new taxes" guys?


[raises hand] Over here! And ditch old ones as well!


The bridge was built with the wrong plates _and_ it passed
inspection. This is not a 'funding' problem except insofar
as public monies seem to attract corruption generally.

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


Ads
  #22  
Old December 29th 18, 04:55 AM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 805
Default Interesting track crashes

On Fri, 28 Dec 2018 20:35:22 -0600, AMuzi wrote:

On 12/28/2018 7:46 PM, Frank Krygowski wrote:
On 12/28/2018 7:35 PM, AMuzi wrote:
On 12/28/2018 6:00 PM, John B. Slocomb wrote:
On Fri, 28 Dec 2018 14:41:12 -0800 (PST),
wrote:

On Wednesday, December 26, 2018 at 4:22:08 PM UTC-8,
John B. Slocomb wrote:
On Wed, 26 Dec 2018 12:02:58 -0800 (PST),
wrote:

On Thursday, November 29, 2018 at 1:25:28 PM UTC-8,
Sir Ridesalot wrote:
An interesting video of track bicycles crashing.
Amazing what happens when a tubular tire comes off
the rim. I was surprised at how long one rider stayed
up - he was okay until the front tire went under his
rear wheel.

I saw bits flying around in some of the crashes but
couldn't make out what those bits were.

https://www.youtube.com/watch?v=tf17hFikqrQ

Cheers

Track tubulars are paper thin so flats from
overheating aren't all that uncommon. My friend who
has turned into a total anti-carbon fiber nut sent me
a video link to a subject he called "carbon fiber rim
exploding under track rider." That isn't what I would
have called it. If you look at it closely it looks
like a track tandem gets a flat in the final sprint
which throws the entire weight of the team unto the
front disk which slowly comes apart as the tire peels
off.

I showed him that foregoing manufacturing errors that
all of the bicycle materials have approximately the
same loaded lifespan. That was sort of surprising to
me since I have a lot of steel bikes and never had a
failure. But I suppose I usually buy them with very
little use and they simply don't have that many miles.

Actually the most common frame material to fail is
aluminum. Come sources say never keep an aluminum
frame for more than 10 years max. And the failures are
highly reminiscent of the Internet pictures of carbon
fiber failures save that the CF bikes usually have
been hit by cars whereas the AL bikes simply fall apart.

Interesting.
Of course Sheldon Brown, that sneaky devil, describes a
study
conducted by EFBe (Engineering for Bikes) which is now,
I believe, one
of the main elements of the DIN 79100 bicycle-testing
standard, which
was published in TOUR magazine of Oct 1997 ( more then
20 years ago)
that demonstrated that two of the three frames that
completed the test
with no failures were welded aluminum frames. Two out
of three... lets
see, that is about 66.666 %, isn't it?

The Christian Bible has a phrase that seems to apply
here (Proverbs
17:28. New International Version)

"Even a fool is thought wise if he keeps silent, and
discerning if he
holds his tongue."

cheers,

John B.

Of course anyone with any training would understand that
this testing meant nothing. While the test itself was
well designed using a single example of each frame
yielded no more information that THAT single example.

But then you're the sort of engineer who would build a
bridge without actually testing the components of it.

I see... first you condemn a test to failure as it tests
only one
example and then you refer to testing bridge components.

Tom, you are a fool. Or do you actually believe that each
component of
a bridge is tested to failure... before it is used?

I worked for a company that specialized in contacting with
international oil companies to build and.or maintain oil
fields in
remote areas and in doing so we built innumerable bridges
and I'm
sorry to inform you that we never tested the components
of any of the
bridges... never. And I can assure you that none of the
bridges ever
fell down.

I might add, that as we were in business for over 20
years, and as oil
companies were still giving us contacts it is patently
obvious that we
knew what we were doing as oil companies don't renew
contacts to
companies that build bridges that fall down.

I keep telling you, "It's better to keep your mouth shut
and appear
stupid than open it and remove all doubt" and you don't
listen.


Indonesia may have some regard for human life and
engineering standards. Not everyone does:

https://am1590theanswer.com/news/nat...10-years-later



"...federal funding has been 'pretty stagnant,' but about 20
states raised taxes to increase their bridge spending."

Where are the "No new taxes" guys?


[raises hand] Over here! And ditch old ones as well!

Tariffs were the largest source of federal revenue from the 1790s to
the eve of World War I - some 120 years.
(Tariffs = import duties)

The bridge was built with the wrong plates _and_ it passed
inspection. This is not a 'funding' problem except insofar
as public monies seem to attract corruption generally.


What is a poor inspector going to do? It is difficult getting by on
just one's salary :-)

cheers,

John B.


  #23  
Old December 30th 18, 06:10 AM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 805
Default Interesting track crashes

On Sun, 30 Dec 2018 12:24:39 +1100, James
wrote:

On 29/12/18 9:49 am, wrote:
On Wednesday, December 26, 2018 at 6:21:44 PM UTC-8, James wrote:



It is silly to claim a particular material is prone to failure,
when the reliability is so heavily influenced by the design,
construction, and use.

-- JS


I would agree to a certain extent. But we're talking about road
racing bikes and hence they were built to the lightest possible
specification and were subjected to the highest possible loadings.

Let me remind you that Boeing chose carbon fiber over aluminum for
reasons other than weight. Of course it is easier to build aircraft
components out of CF since most of the parts can be more carefully
observed for manufacturing errors.


A steel racing frame might weigh 1700 grams, without forks.

From titanium or aluminium, say 1400 grams, also without forks.

Carbon fibre frames *including* forks are usually now under 1000 grams.


Many older racers have broken steel frames made from materials like
Reynolds 753. Ask Jay, for example.

Many have tried aluminium, and some have tried titanium.

Most now are on carbon fibre.


They are all possible to crack or damage. They are all built as light
as the designers dare. Some are too light to survive for more than a
couple of seasons. Some will last for a decade or more of continued use
- regardless of the material they're made from.

Most touring bike frames are still made from steel, but I suspect that a
touring bike frame made from carbon fibre that weighs as much as a steel
frame, would last much longer.


As the British say, "horses for courses" :-)

A Clydesdale will probably never win the Melbourne Cup and a
Thoroughbred can't pull a very big wagon :-)

cheers,

John B.


  #24  
Old December 30th 18, 06:15 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Interesting track crashes

On 12/29/2018 8:24 PM, James wrote:
On 29/12/18 9:49 am, wrote:
On Wednesday, December 26, 2018 at 6:21:44 PM UTC-8, James wrote:



It is silly to claim a particular material is prone to failure,
when the reliability is so heavily influenced by the design,
construction, and use.

-- JS


I would agree to a certain extent. But we're talking about road
racing bikes and hence they were built to the lightest possible
specification and were subjected to the highest possible loadings.

Let me remind you that Boeing chose carbon fiber over aluminum for
reasons other than weight. Of course it is easier to build aircraft
components out of CF since most of the parts can be more carefully
observed for manufacturing errors.


A steel racing frame might weigh 1700 grams, without forks.

From titanium or aluminium, say 1400 grams, also without forks.

Carbon fibre frames *including* forks are usually now under 1000 grams.


Many older racers have broken steel frames made from materials like
Reynolds 753.Â* Ask Jay, for example.

Many have tried aluminium, and some have tried titanium.

Most now are on carbon fibre.


They are all possible to crack or damage.Â* They are all built as light
as the designers dare.Â* Some are too light to survive for more than a
couple of seasons.Â* Some will last for a decade or more of continued use
- regardless of the material they're made from.

Most touring bike frames are still made from steel, but I suspect that a
touring bike frame made from carbon fibre that weighs as much as a steel
frame, would last much longer.


Do people see many examples of touring frames failing?

I've had friends who have broken sporty bike frames made of steel and
aluminum, but I can't recall anyone breaking a touring frame. It may be
because they're designed to handle riding with a full load, but they're
normally ridden empty. One can spend only so much time bike touring,
unless you really devote your entire life to it.

Once, long ago, we stopped at a Warm Showers host for the night. He was
a nice guy who had recently ridden from Illinois to New Mexico and back
on a bike identical to my touring Cannondale. He used wide tires and
rode a lot of gravel roads. By the time he got to New Mexico, the dirt
and gravel had ground a hole through the inside of each chainstay, right
next to the tire.

So what do you do when you've got two new holes in your frame and you're
1000 miles from home? In his case, he just rode the bike back home as it
was! He said he had no problems - but he did retire that frame. It was
hanging in his garage.


--
- Frank Krygowski
  #25  
Old December 30th 18, 07:10 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,261
Default Interesting track crashes

On Friday, December 28, 2018 at 4:00:40 PM UTC-8, John B. Slocomb wrote:
On Fri, 28 Dec 2018 14:41:12 -0800 (PST), wrote:

On Wednesday, December 26, 2018 at 4:22:08 PM UTC-8, John B. Slocomb wrote:
On Wed, 26 Dec 2018 12:02:58 -0800 (PST),
wrote:

On Thursday, November 29, 2018 at 1:25:28 PM UTC-8, Sir Ridesalot wrote:
An interesting video of track bicycles crashing. Amazing what happens when a tubular tire comes off the rim. I was surprised at how long one rider stayed up - he was okay until the front tire went under his rear wheel..

I saw bits flying around in some of the crashes but couldn't make out what those bits were.

https://www.youtube.com/watch?v=tf17hFikqrQ

Cheers

Track tubulars are paper thin so flats from overheating aren't all that uncommon. My friend who has turned into a total anti-carbon fiber nut sent me a video link to a subject he called "carbon fiber rim exploding under track rider." That isn't what I would have called it. If you look at it closely it looks like a track tandem gets a flat in the final sprint which throws the entire weight of the team unto the front disk which slowly comes apart as the tire peels off.

I showed him that foregoing manufacturing errors that all of the bicycle materials have approximately the same loaded lifespan. That was sort of surprising to me since I have a lot of steel bikes and never had a failure.. But I suppose I usually buy them with very little use and they simply don't have that many miles.

Actually the most common frame material to fail is aluminum. Come sources say never keep an aluminum frame for more than 10 years max. And the failures are highly reminiscent of the Internet pictures of carbon fiber failures save that the CF bikes usually have been hit by cars whereas the AL bikes simply fall apart.

Interesting.
Of course Sheldon Brown, that sneaky devil, describes a study
conducted by EFBe (Engineering for Bikes) which is now, I believe, one
of the main elements of the DIN 79100 bicycle-testing standard, which
was published in TOUR magazine of Oct 1997 ( more then 20 years ago)
that demonstrated that two of the three frames that completed the test
with no failures were welded aluminum frames. Two out of three... lets
see, that is about 66.666 %, isn't it?

The Christian Bible has a phrase that seems to apply here (Proverbs
17:28. New International Version)

"Even a fool is thought wise if he keeps silent, and discerning if he
holds his tongue."

cheers,

John B.


Of course anyone with any training would understand that this testing meant nothing. While the test itself was well designed using a single example of each frame yielded no more information that THAT single example.

But then you're the sort of engineer who would build a bridge without actually testing the components of it.


I see... first you condemn a test to failure as it tests only one
example and then you refer to testing bridge components.

Tom, you are a fool. Or do you actually believe that each component of
a bridge is tested to failure... before it is used?

I worked for a company that specialized in contacting with
international oil companies to build and.or maintain oil fields in
remote areas and in doing so we built innumerable bridges and I'm
sorry to inform you that we never tested the components of any of the
bridges... never. And I can assure you that none of the bridges ever
fell down.

I might add, that as we were in business for over 20 years, and as oil
companies were still giving us contacts it is patently obvious that we
knew what we were doing as oil companies don't renew contacts to
companies that build bridges that fall down.

I keep telling you, "It's better to keep your mouth shut and appear
stupid than open it and remove all doubt" and you don't listen.

cheers,

John B.


That's OK. Just continue thinking that everything has to be tested every time because you're that wonderful construction engineer with decades of experience and knowledge of just how components are tested.

Is there absolutely anything that you know about? Because from your massive amount of writing I haven't detected a single thing.
  #26  
Old December 30th 18, 11:28 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,261
Default Interesting track crashes

On Friday, December 28, 2018 at 6:26:28 PM UTC-8, John B. Slocomb wrote:
On Fri, 28 Dec 2018 18:35:48 -0600, AMuzi wrote:

On 12/28/2018 6:00 PM, John B. Slocomb wrote:
On Fri, 28 Dec 2018 14:41:12 -0800 (PST), wrote:

On Wednesday, December 26, 2018 at 4:22:08 PM UTC-8, John B. Slocomb wrote:
On Wed, 26 Dec 2018 12:02:58 -0800 (PST),
wrote:

On Thursday, November 29, 2018 at 1:25:28 PM UTC-8, Sir Ridesalot wrote:
An interesting video of track bicycles crashing. Amazing what happens when a tubular tire comes off the rim. I was surprised at how long one rider stayed up - he was okay until the front tire went under his rear wheel.

I saw bits flying around in some of the crashes but couldn't make out what those bits were.

https://www.youtube.com/watch?v=tf17hFikqrQ

Cheers

Track tubulars are paper thin so flats from overheating aren't all that uncommon. My friend who has turned into a total anti-carbon fiber nut sent me a video link to a subject he called "carbon fiber rim exploding under track rider." That isn't what I would have called it. If you look at it closely it looks like a track tandem gets a flat in the final sprint which throws the entire weight of the team unto the front disk which slowly comes apart as the tire peels off.

I showed him that foregoing manufacturing errors that all of the bicycle materials have approximately the same loaded lifespan. That was sort of surprising to me since I have a lot of steel bikes and never had a failure. But I suppose I usually buy them with very little use and they simply don't have that many miles.

Actually the most common frame material to fail is aluminum. Come sources say never keep an aluminum frame for more than 10 years max. And the failures are highly reminiscent of the Internet pictures of carbon fiber failures save that the CF bikes usually have been hit by cars whereas the AL bikes simply fall apart.

Interesting.
Of course Sheldon Brown, that sneaky devil, describes a study
conducted by EFBe (Engineering for Bikes) which is now, I believe, one
of the main elements of the DIN 79100 bicycle-testing standard, which
was published in TOUR magazine of Oct 1997 ( more then 20 years ago)
that demonstrated that two of the three frames that completed the test
with no failures were welded aluminum frames. Two out of three... lets
see, that is about 66.666 %, isn't it?

The Christian Bible has a phrase that seems to apply here (Proverbs
17:28. New International Version)

"Even a fool is thought wise if he keeps silent, and discerning if he
holds his tongue."

cheers,

John B.

Of course anyone with any training would understand that this testing meant nothing. While the test itself was well designed using a single example of each frame yielded no more information that THAT single example.

But then you're the sort of engineer who would build a bridge without actually testing the components of it.

I see... first you condemn a test to failure as it tests only one
example and then you refer to testing bridge components.

Tom, you are a fool. Or do you actually believe that each component of
a bridge is tested to failure... before it is used?

I worked for a company that specialized in contacting with
international oil companies to build and.or maintain oil fields in
remote areas and in doing so we built innumerable bridges and I'm
sorry to inform you that we never tested the components of any of the
bridges... never. And I can assure you that none of the bridges ever
fell down.

I might add, that as we were in business for over 20 years, and as oil
companies were still giving us contacts it is patently obvious that we
knew what we were doing as oil companies don't renew contacts to
companies that build bridges that fall down.

I keep telling you, "It's better to keep your mouth shut and appear
stupid than open it and remove all doubt" and you don't listen.



Indonesia may have some regard for human life and
engineering standards. Not everyone does:

https://am1590theanswer.com/news/nat...10-years-later


Well, the bridge was ~50 years old and had some 300 tons of
construction materials stockpiled on the deck for renovations :-)

The English built an iron bridge in 1781, that is still in use. Or
better yet, the Greeks. They built a bridge ~3,000+ years ago that is
still in use :-)

But you will persist in having things built by the low bidders :-(

cheers,

John B.



You seem to have missed that it was never designed to convey heavy traffic, that it was constructed of cast iron and that because of fear of collapse from even mule trains it was closed in 1934.

But then that is the way you conduct your conversations - with lies interspersed with minute truths.

Ponte Fabricio, in Rome, was built in 62 BC. The bridge is almost unchanged, and still serves thousands of Romans today.
  #27  
Old December 31st 18, 01:41 AM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 805
Default Interesting track crashes

On Sun, 30 Dec 2018 10:10:08 -0800 (PST), wrote:

On Friday, December 28, 2018 at 4:00:40 PM UTC-8, John B. Slocomb wrote:
On Fri, 28 Dec 2018 14:41:12 -0800 (PST),
wrote:

On Wednesday, December 26, 2018 at 4:22:08 PM UTC-8, John B. Slocomb wrote:
On Wed, 26 Dec 2018 12:02:58 -0800 (PST),
wrote:

On Thursday, November 29, 2018 at 1:25:28 PM UTC-8, Sir Ridesalot wrote:
An interesting video of track bicycles crashing. Amazing what happens when a tubular tire comes off the rim. I was surprised at how long one rider stayed up - he was okay until the front tire went under his rear wheel.

I saw bits flying around in some of the crashes but couldn't make out what those bits were.

https://www.youtube.com/watch?v=tf17hFikqrQ

Cheers

Track tubulars are paper thin so flats from overheating aren't all that uncommon. My friend who has turned into a total anti-carbon fiber nut sent me a video link to a subject he called "carbon fiber rim exploding under track rider." That isn't what I would have called it. If you look at it closely it looks like a track tandem gets a flat in the final sprint which throws the entire weight of the team unto the front disk which slowly comes apart as the tire peels off.

I showed him that foregoing manufacturing errors that all of the bicycle materials have approximately the same loaded lifespan. That was sort of surprising to me since I have a lot of steel bikes and never had a failure. But I suppose I usually buy them with very little use and they simply don't have that many miles.

Actually the most common frame material to fail is aluminum. Come sources say never keep an aluminum frame for more than 10 years max. And the failures are highly reminiscent of the Internet pictures of carbon fiber failures save that the CF bikes usually have been hit by cars whereas the AL bikes simply fall apart.

Interesting.
Of course Sheldon Brown, that sneaky devil, describes a study
conducted by EFBe (Engineering for Bikes) which is now, I believe, one
of the main elements of the DIN 79100 bicycle-testing standard, which
was published in TOUR magazine of Oct 1997 ( more then 20 years ago)
that demonstrated that two of the three frames that completed the test
with no failures were welded aluminum frames. Two out of three... lets
see, that is about 66.666 %, isn't it?

The Christian Bible has a phrase that seems to apply here (Proverbs
17:28. New International Version)

"Even a fool is thought wise if he keeps silent, and discerning if he
holds his tongue."

cheers,

John B.

Of course anyone with any training would understand that this testing meant nothing. While the test itself was well designed using a single example of each frame yielded no more information that THAT single example.

But then you're the sort of engineer who would build a bridge without actually testing the components of it.


I see... first you condemn a test to failure as it tests only one
example and then you refer to testing bridge components.

Tom, you are a fool. Or do you actually believe that each component of
a bridge is tested to failure... before it is used?

I worked for a company that specialized in contacting with
international oil companies to build and.or maintain oil fields in
remote areas and in doing so we built innumerable bridges and I'm
sorry to inform you that we never tested the components of any of the
bridges... never. And I can assure you that none of the bridges ever
fell down.

I might add, that as we were in business for over 20 years, and as oil
companies were still giving us contacts it is patently obvious that we
knew what we were doing as oil companies don't renew contacts to
companies that build bridges that fall down.

I keep telling you, "It's better to keep your mouth shut and appear
stupid than open it and remove all doubt" and you don't listen.

cheers,

John B.


That's OK. Just continue thinking that everything has to be tested every time because you're that wonderful construction engineer with decades of experience and knowledge of just how components are tested.

Is there absolutely anything that you know about? Because from your massive amount of writing I haven't detected a single thing.


Yes, I'm sure that you "haven't detected a single thing" as I have
repeatedly told you in no uncertain terms that "It's better to keep
your mouth shut and appear stupid than open it and remove all
doubt"... and you haven't yet learned a thing.

And, it isn't just me, although I am, perhaps, the most outspoken. But
my reading of the site seems to indicate that every one of the posters
has, with more or less delicacy, told you that you are full of the
brown stuff.

Or in more genteel terms, "It is said that the eyes are a window unto
the soul", which would indicate that you have brown eyes.

cheers,

John B.


  #28  
Old December 31st 18, 01:59 AM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 805
Default Interesting track crashes

On Sun, 30 Dec 2018 14:28:02 -0800 (PST), wrote:

On Friday, December 28, 2018 at 6:26:28 PM UTC-8, John B. Slocomb wrote:
On Fri, 28 Dec 2018 18:35:48 -0600, AMuzi wrote:

On 12/28/2018 6:00 PM, John B. Slocomb wrote:
On Fri, 28 Dec 2018 14:41:12 -0800 (PST),
wrote:

On Wednesday, December 26, 2018 at 4:22:08 PM UTC-8, John B. Slocomb wrote:
On Wed, 26 Dec 2018 12:02:58 -0800 (PST),
wrote:

On Thursday, November 29, 2018 at 1:25:28 PM UTC-8, Sir Ridesalot wrote:
An interesting video of track bicycles crashing. Amazing what happens when a tubular tire comes off the rim. I was surprised at how long one rider stayed up - he was okay until the front tire went under his rear wheel.

I saw bits flying around in some of the crashes but couldn't make out what those bits were.

https://www.youtube.com/watch?v=tf17hFikqrQ

Cheers

Track tubulars are paper thin so flats from overheating aren't all that uncommon. My friend who has turned into a total anti-carbon fiber nut sent me a video link to a subject he called "carbon fiber rim exploding under track rider." That isn't what I would have called it. If you look at it closely it looks like a track tandem gets a flat in the final sprint which throws the entire weight of the team unto the front disk which slowly comes apart as the tire peels off.

I showed him that foregoing manufacturing errors that all of the bicycle materials have approximately the same loaded lifespan. That was sort of surprising to me since I have a lot of steel bikes and never had a failure. But I suppose I usually buy them with very little use and they simply don't have that many miles.

Actually the most common frame material to fail is aluminum. Come sources say never keep an aluminum frame for more than 10 years max. And the failures are highly reminiscent of the Internet pictures of carbon fiber failures save that the CF bikes usually have been hit by cars whereas the AL bikes simply fall apart.

Interesting.
Of course Sheldon Brown, that sneaky devil, describes a study
conducted by EFBe (Engineering for Bikes) which is now, I believe, one
of the main elements of the DIN 79100 bicycle-testing standard, which
was published in TOUR magazine of Oct 1997 ( more then 20 years ago)
that demonstrated that two of the three frames that completed the test
with no failures were welded aluminum frames. Two out of three... lets
see, that is about 66.666 %, isn't it?

The Christian Bible has a phrase that seems to apply here (Proverbs
17:28. New International Version)

"Even a fool is thought wise if he keeps silent, and discerning if he
holds his tongue."

cheers,

John B.

Of course anyone with any training would understand that this testing meant nothing. While the test itself was well designed using a single example of each frame yielded no more information that THAT single example.

But then you're the sort of engineer who would build a bridge without actually testing the components of it.

I see... first you condemn a test to failure as it tests only one
example and then you refer to testing bridge components.

Tom, you are a fool. Or do you actually believe that each component of
a bridge is tested to failure... before it is used?

I worked for a company that specialized in contacting with
international oil companies to build and.or maintain oil fields in
remote areas and in doing so we built innumerable bridges and I'm
sorry to inform you that we never tested the components of any of the
bridges... never. And I can assure you that none of the bridges ever
fell down.

I might add, that as we were in business for over 20 years, and as oil
companies were still giving us contacts it is patently obvious that we
knew what we were doing as oil companies don't renew contacts to
companies that build bridges that fall down.

I keep telling you, "It's better to keep your mouth shut and appear
stupid than open it and remove all doubt" and you don't listen.


Indonesia may have some regard for human life and
engineering standards. Not everyone does:

https://am1590theanswer.com/news/nat...10-years-later


Well, the bridge was ~50 years old and had some 300 tons of
construction materials stockpiled on the deck for renovations :-)

The English built an iron bridge in 1781, that is still in use. Or
better yet, the Greeks. They built a bridge ~3,000+ years ago that is
still in use :-)

But you will persist in having things built by the low bidders :-(

cheers,

John B.



You seem to have missed that it was never designed to convey heavy traffic, that it was constructed of cast iron and that because of fear of collapse from even mule trains it was closed in 1934.


Yes, you are partially correct. So to put it another way, they
constructed a bridge that was in use from 1781 until 1934 it was
designated a Scheduled Ancient Monument and closed to vehicular
traffic.

And you missed the fact that "It was the only bridge on the River
Severn to survive the flood of February 1795 undamaged

So the bridge was used by any and all to cross the river for some 153
years.

But then that is the way you conduct your conversations - with lies interspersed with minute truths.


Minute truths? that the first iron bridge was used for all traffic for
150 years and is still open... to pedestrian traffic?


Ponte Fabricio, in Rome, was built in 62 BC. The bridge is almost unchanged, and still serves thousands of Romans today.


Ah yes, "serves thousands of Romans today"....

Certainly, just so long as they walk across as it is restricted to
pedestrian traffic.

As Mark Twain was said to have expounded, "It's better to keep your
mouth shut and appear stupid than open it and remove all doubt".

cheers,

John B.


  #29  
Old January 1st 19, 10:13 PM posted to rec.bicycles.tech
James[_8_]
external usenet poster
 
Posts: 6,153
Default Interesting track crashes

On 31/12/18 4:15 am, Frank Krygowski wrote:
On 12/29/2018 8:24 PM, James wrote:



Most touring bike frames are still made from steel, but I suspect that
a touring bike frame made from carbon fibre that weighs as much as a
steel frame, would last much longer.


Do people see many examples of touring frames failing?


From rust mostly I suspect ;-)

But that isn't a problem for a CFRP frame.


I've had friends who have broken sporty bike frames made of steel and
aluminum, but I can't recall anyone breaking a touring frame. It may be
because they're designed to handle riding with a full load, but they're
normally ridden empty. One can spend only so much time bike touring,
unless you really devote your entire life to it.

Once, long ago, we stopped at a Warm Showers host for the night. He was
a nice guy who had recently ridden from Illinois to New Mexico and back
on a bike identical to my touring Cannondale. He used wide tires and
rode a lot of gravel roads. By the time he got to New Mexico, the dirt
and gravel had ground a hole through the inside of each chainstay, right
next to the tire.

So what do you do when you've got two new holes in your frame and you're
1000 miles from home? In his case, he just rode the bike back home as it
was! He said he had no problems - but he did retire that frame. It was
hanging in his garage.



Yep. That damage could happen to any frame regardless of material. How
long before it happens depends on the abrasion resistance of the
material I suppose.

--
JS
 




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