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.