Rim failure

Quoted message said:

Here is a collection of classic failures:

http://pardo.net/bike/pic/fail-001/FAIL-070.html

Jobst Brandt

Jobst,

Those look severe and I'm not surprised they're old Mavics. Let me
take some guesses..

1. The first set of four pictures look dark to me as opposed to the
rim down below. I might be wrong, but they do mention ceramic coated,
does that mean they were hard anodized? Its probably crazing then...

2. Excessive spoke tension in the lower rims ( 517 SUP)? The spoke was
pulled right through. Not good..

Ron
http://cozybeehive.blogspot.com

Ron George said:

Quoted message said:

Here is a collection of classic failures:

http://pardo.net/bike/pic/fail-001/FAIL-070.html

Jobst Brandt

Jobst,

Those look severe and I'm not surprised they're old Mavics. Let me
take some guesses..

1. The first set of four pictures look dark to me as opposed to the
rim down below. I might be wrong, but they do mention ceramic coated,
does that mean they were hard anodized? Its probably crazing then...

It could be too much tyre pressure in too fat a tyre that broke the
first rim.

Ben C said:

Ron George said:

Quoted message said:

Here is a collection of classic failures:

Quoted message said:

Quoted message said:

http://pardo.net/bike/pic/fail-001/FAIL-070.html

Quoted message said:

Quoted message said:

Jobst Brandt

Quoted message said:

Jobst,

Quoted message said:

Those look severe and I'm not surprised they're old Mavics. Let me
take some guesses..

Quoted message said:

1. The first set of four pictures look dark to me as opposed to the
rim down below. I might be wrong, but they do mention ceramic coated,
does that mean they were hard anodized? Its probably crazing then...

It could be too much tyre pressure in too fat a tyre that broke the
first rim.

Ben,

Could be, but how much is too much?

Ron
http://cozybeehive.blogspot.com

Ron George said:

Ben C said:

Ron George said:

On Jan 23, 1:51 pm, [email hidden] wrote:
> Here is a collection of classic failures:

Quoted message said:

>http://pardo.net/bike/pic/fail-001/FAIL-070.html

Quoted message said:

> Jobst Brandt

Quoted message said:

Jobst,

Quoted message said:

Those look severe and I'm not surprised they're old Mavics. Let me
take some guesses..

Quoted message said:

1. The first set of four pictures look dark to me as opposed to the
rim down below. I might be wrong, but they do mention ceramic coated,
does that mean they were hard anodized? Its probably crazing then...

It could be too much tyre pressure in too fat a tyre that broke the
first rim.

Ben,

Could be, but how much is too much?

Ron
http://cozybeehive.blogspot.com

Dear Ron,

Page way down here on Sheldon's site to Georg Boerner's table of rim
width versus tire width:
http://www.sheldonbrown.com/tire_sizing.html

Rim manufacturers often give maximum tire widths for rims. You can see
some of this in action in this thread about a rim that "mysteriously"
exploded with a very heavy rider and an overinflated tire that was far
too wide for its rim:
http://groups.google.com/group/rec.bicycles.tech/msg/bd5c34432503e882

Cheers,

Carl Fogel

Ron George said:

Ben C said:

On 2008-01-23, Ron George <[email hidden]> wrote:

Quoted message said:

Quoted message said:

On Jan 23, 1:51 pm, [email hidden] wrote:
> Here is a collection of classic failures:

Quoted message said:

Quoted message said:

>http://pardo.net/bike/pic/fail-001/FAIL-070.html

Quoted message said:

Quoted message said:

> Jobst Brandt

Quoted message said:

Quoted message said:

Jobst,

Quoted message said:

Quoted message said:

Those look severe and I'm not surprised they're old Mavics.  Let me
take some guesses..

Quoted message said:

Quoted message said:

1. The first set of four pictures look dark to me as opposed to the
rim down below. I might be wrong, but they do mention ceramic coated,
does that mean they were hard anodized? Its probably crazing then...

Quoted message said:

It could be too much tyre pressure in too fat a tyre that broke the
first rim.

Ben,

Could be, but how much is too much?

Ronhttp://cozybeehive.blogspot.com- Hide quoted text -

- Show quoted text -

At one time, Mavic listed such specs on their home page. I just
checked, and they don't any more. Maybe that info's on their password-
protected dealer site that jb gets his spoke tension specs from.

Quoted message said:

Dear Ron,

Quoted message said:

Page way down here on Sheldon's site to Georg Boerner's table of rim
width versus tire width:
http://www.sheldonbrown.com/tire_sizing.html

That's a fascinating table, but I think It can sum it up concisely as
follows :

- tire width should be in the range [50%, 100%] wider than rim
width.

- Don Gillies
San Diego, CA, USA

(Donald Gillies) said:

Quoted message said:

Dear Ron,
Page way down here on Sheldon's site to Georg Boerner's table of rim
width versus tire width:
http://www.sheldonbrown.com/tire_sizing.html

That's a fascinating table, but I think It can sum it up concisely as
follows :

- tire width should be in the range [50%, 100%] wider than rim
    width.

- Don Gillies
San Diego, CA, USA

But it's more than just width - pressure factors in there, too. A 32mm
tire may be OK on a 15mm inner width rim at 60psi, and OK on a 17mm IW
rim at 90psi, and the tire says it's rated for 95psi, but you
shouldn't use the 32mm tire on a 15mm rim at 90psi, because the
sidewall stress is far greater than the 50% increase in pressure would
suggest.

(Donald Gillies) said:

Quoted message said:

Dear Ron,
Page way down here on Sheldon's site to Georg Boerner's table of rim
width versus tire width:
http://www.sheldonbrown.com/tire_sizing.html

That's a fascinating table, but I think It can sum it up concisely as
follows :

- tire width should be in the range [50%, 100%] wider than rim
    width.

- Don Gillies
San Diego, CA, USA

But it's more than just width - pressure factors in there, too. A 32mm
tire may be OK on a 15mm inner width rim at 60psi, and OK on a 17mm IW
rim at 90psi, and the tire says it's rated for 95psi, but you
shouldn't use the 32mm tire on a 15mm rim at 90psi, because the
sidewall stress is far greater than the 50% increase in pressure would
suggest.

Hank said:

At one time, Mavic listed such specs on their home page. I just
checked, and they don't any more. Maybe that info's on their password-
protected dealer site that jb gets his spoke tension specs from.

Jobst Brandt is a Mavic dealer?

In article <[email hidden]>,

_ said:

Hank said:

At one time, Mavic listed such specs on their home page. I just
checked, and they don't any more. Maybe that info's on their
password- protected dealer site that jb gets his spoke tension
specs from.

Jobst Brandt is a Mavic dealer?

jb not JB. Given the beamster's constant shilling for Mavic, I figure
he works for Mavic USA.

desperately seeking relevance said:

Here is a collection of classic failures:

http://pardo.net/bike/pic/fail-001/FAIL-070.html

which are simply over-inflation and over-tension. [the latter also
being classic examples that shoot "anodizing theory" right in the foot
since the cracks follow the extrusion axis, not the anodizing cracks.]

i don't ever recall you advocating the former jobst, but the latter is
yet another rim killed by your spoke tension "as high as the rim can bear".

and on that note, for how much longer are your going to be shamed by
gerdt schraner? he advocates the use of a tensiometer - you just use
hocus pocus. when are your book revisions due?

jim beam said:

i don't ever recall you advocating the former jobst, but the latter is
yet another rim killed by your spoke tension "as high as the rim can bear".

Hmm. Looks to me like that was tension higher than the rim could
bear. No?

- Frank Krygowski

Quoted message said:

jim beam said:

i don't ever recall you advocating the former jobst, but the latter is
yet another rim killed by your spoke tension "as high as the rim can bear".

Hmm. Looks to me like that was tension higher than the rim could
bear. No?

you know, for someone that masquerades as an engineering professor, you
seem to have a woefully poor grasp of the difference between static load
and dynamic load.

Tim McNamara said:

In article <[email hidden]>,

_ said:

Hank said:

At one time, Mavic listed such specs on their home page. I just
checked, and they don't any more. Maybe that info's on their
password- protected dealer site that jb gets his spoke tension
specs from.

Jobst Brandt is a Mavic dealer?

jb not JB. Given the beamster's constant shilling for Mavic, I figure
he works for Mavic USA.

If that's true, it would be a pretty powerful inducement for him to hide
himself behind an anonymous account - forwarding any one of the hundreds of
his abusive posts to an employer might be a career-killer.

jtaylor said:

Tim McNamara said:

In article <[email hidden]>,
 _ <[email hidden]> wrote:

Quoted message said:

Quoted message said:

On Wed, 23 Jan 2008 12:24:06 -0800 (PST), Hank wrote:

Quoted message said:

Quoted message said:

> At one time, Mavic listed such specs on their home page. I just
> checked, and they don't any more. Maybe that info's on their
> password- protected dealer site that jb gets his spoke tension
> specs from.

Quoted message said:

Quoted message said:

Jobst Brandt is a Mavic dealer?

Quoted message said:

jb not JB.  Given the beamster's constant shilling for Mavic, I figure
he works for Mavic USA.

If that's true, it would be a pretty powerful inducement for him to hide
himself behind an anonymous account - forwarding any one of the hundreds of
his abusive posts to an employer might be a career-killer.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

"jtaylor" reminds us of the type of sleazy, spiteful little [censored]
he truly is.

_ said:

Tim McNamara said:

In article <[email hidden]>,

_ said:

On Wed, 23 Jan 2008 12:24:06 -0800 (PST), Hank wrote:

> At one time, Mavic listed such specs on their home page. I just
> checked, and they don't any more. Maybe that info's on their
> password- protected dealer site that jb gets his spoke tension
> specs from.
Jobst Brandt is a Mavic dealer?

jb not JB. Given the beamster's constant shilling for Mavic, I figure
he works for Mavic USA.

If that's true, it would be a pretty powerful inducement for him to hide
himself behind an anonymous account - forwarding any one of the hundreds of
his abusive posts to an employer might be a career-killer.

go ahead! i'll consider my options on firing myself. maybe you want to
complain to my mom instead? i'm sure she'd love to hear from you.

otoh, you can resolve your, er, "confusion" on whether calling out fraud
and incompetence is "abusive". but i guess slowly realizing that you
were gullibly taken in must be painful and cause resentment.