Total wheel Failure

How many of you would put an identical wheel/tire/pressure in as a
replacement and continue riding?

Werehatrack said:

Quoted message said:

http://bikeforums.net/showthread.php?t=201510

I'll weigh in with what I think.

I believe that the first failure was the short break, and I suspect
that an examination of the parting surfaces will reveal that the crack
had started early and had migrated; I'm pretty sure that part of that
surface will show work-polishing indicative of a fracture under
varying stresses. When the crack finally went all the way through,
the rim separated while rotating, one end jammed on a seat stay (I
suspect that the location of the impact will not be hard to identify),
and the sudden cessation of rotation of that end of the band caused
the upward leap as traction and inertia pulled the gap open, wrinkling
the rest of the rim and causing the secondary, larger tear in the
process. The loud bang was the tube blowing out as the gap opened up
between the ends of the failed rim hoop.

The current clock position of the rim in the rear triangle is not
indicative of much of anything; I'm sure it was rotated between the
time of the failure and the time when the photos were taken.

IMO, yes, Mavic owes the bike owner a new wheel.

You may be right, it's hard to tell with just these pictures to work
from. I'll offer the contrary theory here, just in case you're wrong. 😉

I suspect there was an incipient failure at the spoke hole at the middle
of the longer break; note the crosswise crack at the upper half of the
spoke in the second picture. When this crack propagated far enough, it
failed catastrophically, leaving the rim sidewalls to carry the entire
compressive load. The sidewalls folded inward, with the bottom side
failing outward, which the hoop stress then folded back. (Note this
could be the site of the "tire-pumped-up-too-much" failure, but I don't
see how that would create the diagonal tear across the rim anchored at
one end of the tear.) I suspect the short tear was caused by the wheel
folding over across the diameter from the original break.

I'm not sure if the rim tape tear at the top is significant or not. It
tells me the top tear was from the left side, which indicates (but
doesn't conclusively prove) the sidewall blowout was secondary to the
rim failure. However, if you're right about the first failure happening
at the short tear on the bottom, it's merely an interesting sidebar.

I agree the current position is meaningless. Severely bent spokes occur
around 120 degrees of the wheel. Those had to drag against something
(dropout?) while the wheel was rotating/decelerating.

The guy is owed a wheel. Maybe from the builder, if he overtensioned
the spoke leading to failure. Maybe from Mavic, otherwise.

Pat

Quoted message said:

How many of you would put an identical wheel/tire/pressure in as a
replacement and continue riding?

Dear D.,

I wouldn't put a 37mm tire on a rim recommended for no more than 28mm
and 117 psi and then blow it up to an estimated 80-85 psi,
particularly if I weighed 275 lbs.

I've heard of a case where the wheel failed catastrophically within
500 miles on smooth pavement when this was done.

Cheers,

Carl Fogel

Quoted message said:

Quoted message said:

How many of you would put an identical wheel/tire/pressure in as a
replacement and continue riding?

Dear D.,

I wouldn't put a 37mm tire on a rim recommended for no more than 28mm
and 117 psi and then blow it up to an estimated 80-85 psi,
particularly if I weighed 275 lbs.

I've heard of a case where the wheel failed catastrophically within
500 miles on smooth pavement when this was done.

Cheers,

Carl Fogel

How about a 28mm tire?

Quoted message said:

Quoted message said:

Quoted message said:

How many of you would put an identical wheel/tire/pressure in as a
replacement and continue riding?

Dear D.,

I wouldn't put a 37mm tire on a rim recommended for no more than 28mm
and 117 psi and then blow it up to an estimated 80-85 psi,
particularly if I weighed 275 lbs.

I've heard of a case where the wheel failed catastrophically within
500 miles on smooth pavement when this was done.

Cheers,

Carl Fogel

How about a 28mm tire?

Dear D.,

I'd happily put a 28mm tire on a rim rated for that width with no more
than 117 psi--and inflate it to about 100 psi or less. A recommended
maximum is a warning, not an invitation to see what happens.

In any case, the destroyed rim was wearing a 37mm tire inflated to an
estimated 80-85 psi when it abruptly tore itself in half after only
500 miles.

That 37mm is 32% beyond the CXP33's maximum recommended width.

What could be a more impressive and dramatic illustration that Mavic
was right about those rim limits? Or that wider tires exert more
leverage on rims?

Cheers,

Carl Fogel

Quoted message said:

Quoted message said:

Quoted message said:

On 7 Jun 2006 08:08:23 -0700, [email hidden] wrote:

>How many of you would put an identical wheel/tire/pressure in as a
>replacement and continue riding?

Dear D.,

I wouldn't put a 37mm tire on a rim recommended for no more than 28mm
and 117 psi and then blow it up to an estimated 80-85 psi,
particularly if I weighed 275 lbs.

I've heard of a case where the wheel failed catastrophically within
500 miles on smooth pavement when this was done.

Cheers,

Carl Fogel

How about a 28mm tire?

Dear D.,

I'd happily put a 28mm tire on a rim rated for that width with no more
than 117 psi--and inflate it to about 100 psi or less. A recommended
maximum is a warning, not an invitation to see what happens.

In any case, the destroyed rim was wearing a 37mm tire inflated to an
estimated 80-85 psi when it abruptly tore itself in half after only
500 miles.

That 37mm is 32% beyond the CXP33's maximum recommended width.

What could be a more impressive and dramatic illustration that Mavic
was right about those rim limits? Or that wider tires exert more
leverage on rims?

Cheers,

Carl Fogel

And weighing 275 pounds you would ride happily into the sunset with a
28mm at 117 psi. Never a 2nd thought?

Quoted message said:

Quoted message said:

Quoted message said:

[email hidden] wrote:
> On 7 Jun 2006 08:08:23 -0700, [email hidden] wrote:
>
>> How many of you would put an identical wheel/tire/pressure in as a
>> replacement and continue riding?
> Dear D.,
>
> I wouldn't put a 37mm tire on a rim recommended for no more than 28mm
> and 117 psi and then blow it up to an estimated 80-85 psi,
> particularly if I weighed 275 lbs.
>
> I've heard of a case where the wheel failed catastrophically within
> 500 miles on smooth pavement when this was done.
>
> Cheers,
>
> Carl Fogel
How about a 28mm tire?

Dear D.,

I'd happily put a 28mm tire on a rim rated for that width with no more
than 117 psi--and inflate it to about 100 psi or less. A recommended
maximum is a warning, not an invitation to see what happens.

In any case, the destroyed rim was wearing a 37mm tire inflated to an
estimated 80-85 psi when it abruptly tore itself in half after only
500 miles.

That 37mm is 32% beyond the CXP33's maximum recommended width.

What could be a more impressive and dramatic illustration that Mavic
was right about those rim limits? Or that wider tires exert more
leverage on rims?

Cheers,

Carl Fogel

And weighing 275 pounds you would ride happily into the sunset with a
28mm at 117 psi. Never a 2nd thought?

Yup and do everyday....Michelin carbons on velocity aero 36 spoke

mrbubl said:

Quoted message said:

Quoted message said:

On 7 Jun 2006 12:07:36 -0700, [email hidden] wrote:

> [email hidden] wrote:
>> On 7 Jun 2006 08:08:23 -0700, [email hidden] wrote:
>>
>>> How many of you would put an identical wheel/tire/pressure in as a
>>> replacement and continue riding?
>> Dear D.,
>>
>> I wouldn't put a 37mm tire on a rim recommended for no more than 28mm
>> and 117 psi and then blow it up to an estimated 80-85 psi,
>> particularly if I weighed 275 lbs.
>>
>> I've heard of a case where the wheel failed catastrophically within
>> 500 miles on smooth pavement when this was done.
>>
>> Cheers,
>>
>> Carl Fogel
> How about a 28mm tire?
Dear D.,

I'd happily put a 28mm tire on a rim rated for that width with no more
than 117 psi--and inflate it to about 100 psi or less. A recommended
maximum is a warning, not an invitation to see what happens.

In any case, the destroyed rim was wearing a 37mm tire inflated to an
estimated 80-85 psi when it abruptly tore itself in half after only
500 miles.

That 37mm is 32% beyond the CXP33's maximum recommended width.

What could be a more impressive and dramatic illustration that Mavic
was right about those rim limits? Or that wider tires exert more
leverage on rims?

Cheers,

Carl Fogel

And weighing 275 pounds you would ride happily into the sunset with a
28mm at 117 psi. Never a 2nd thought?

Yup and do everyday....Michelin carbons on velocity aero 36 spoke

You ,missed the point of the question, which was, "Would you go out on
THOSE rims (the rim-type that failed so catastrophically) at 117psi,
28mm and 275 pounds."

Perhaps you haven't read the thread?

It was NOT about 36 spoke wheels.

I suggest the rider needs a 500+ g rim, such as at minimum an Ambrosio
Evolution (480g, 13.5mm

Quoted message said:

ERTRO width, <http://www.ambrosiospa.com/cerchi_corsa.htm>😉, much better an Ambrosio Keba (610g, 18mm ERTRO width, <http://www.ambrosiospa.com/touring.htm>😉.

Hi! I'm the clydesdale whose Mavic blew up, instigating this thread.
I'm planning on having all my wheels rebuilt with different rims (I'm
scared of those Mavics now...). I'm not familiar with Ambrosio rims.
I note that Ambrosio offers multiple "touring" rims with wider
profiles. What differences are there between the different Ambrosio
touring rims, and which is the strongest?

Thanks!

[email hidden] a écrit :

Quoted message said:

mrbubl said:

Quoted message said:

And weighing 275 pounds you would ride happily into the sunset with a
28mm at 117 psi. Never a 2nd thought?

Yup and do everyday....Michelin carbons on velocity aero 36 spoke

You ,missed the point of the question, which was, "Would you go out on
THOSE rims (the rim-type that failed so catastrophically) at 117psi,
28mm and 275 pounds."

Perhaps you haven't read the thread?

It was NOT about 36 spoke wheels.

So ? CXP33, yes ? Sure, get out and ride them. They are notably
stiff, keep true, work well.
But to look more closely, the first thing to do is lose at least 75 pounds.
Easier to blame equipment, I guess. Ride enough, and there's no need
for that Q,

Sandy said:

[email hidden] a écrit :

Quoted message said:

mrbubl said:

> And weighing 275 pounds you would ride happily into the sunset with a
> 28mm at 117 psi. Never a 2nd thought?
>
>
Yup and do everyday....Michelin carbons on velocity aero 36 spoke

You ,missed the point of the question, which was, "Would you go out on
THOSE rims (the rim-type that failed so catastrophically) at 117psi,
28mm and 275 pounds."

Perhaps you haven't read the thread?

It was NOT about 36 spoke wheels.

So ? CXP33, yes ? Sure, get out and ride them. They are notably
stiff, keep true, work well.
But to look more closely, the first thing to do is lose at least 75 pounds.
Easier to blame equipment, I guess. Ride enough, and there's no need
for that Q,

You are confusing me and the person for whom the wheel failed. But, I
guess it is not the first time I have been mistaken for someone else,
nor likely the last!

PTL, I only weigh about 220 lbs, and my Mavics on my Lemond have held
up just fine for 8 years now.

But, thanks for your kind thoughts.

[email hidden] a écrit :

Quoted message said:

I suggest the rider needs a 500+ g rim, such as at minimum an Ambrosio
Evolution (480g, 13.5mm

Quoted message said:

ERTRO width, <http://www.ambrosiospa.com/cerchi_corsa.htm>😉, much better an Ambrosio Keba (610g, 18mm ERTRO width, <http://www.ambrosiospa.com/touring.htm>😉.

Hi! I'm the clydesdale whose Mavic blew up, instigating this thread.
I'm planning on having all my wheels rebuilt with different rims (I'm
scared of those Mavics now...). I'm not familiar with Ambrosio rims.
I note that Ambrosio offers multiple "touring" rims with wider
profiles. What differences are there between the different Ambrosio
touring rims, and which is the strongest?

Thanks!

Briefly, that would be dumb and wasteful

Quoted message said:

Quoted message said:

I'm planning on having all my wheels rebuilt with different rims

Quoted message said:

Briefly, that would be dumb and wasteful

Why? If the Mavics have quality control problems, isn't it possible
that the remaining rims could likely fail also? If I could
definitively establish that excess tire width was the root-cause of
this wheel failure, I'd be happy to continue using the Mavics with tire
sizes recommended by Mavic. Unfortunately, I don't think that has been
established (nor do I think it can be). I'm left with wheels that I
can't trust. So let's cut to the chase - why do you think my decision
to replace the Mavic rims is dumb and wasteful? Thanks!

ok...so this makes lots of sense.....

but why haven't there been issues with the DT Swiss RR 1.1 rims
(622-15) being used with 30 mm + wide cyclocross tires?

this seems a most extreme example.

i know of at least 13 riders who race for a shop. all on the 1.1 rims
with a kevlar beaded Maxxis Locust CX tire (35mm). they've been using
this rim and tire combo for almost a year now....and some even do urban
rides without swapping out to a smoother tire.

Quoted message said:

Antti Salonen wrote:

<snip>

Quoted message said:

Usually the wider
the tyre the lower the pressure, so the rim should be fine.

-as

Hi Antti,

Don't forget that the force exerted by the tire on the rim scales with
the radius of the tire section (that is, with the surface area of the
casing). A wide tire at lowish pressure can exert more force at the
bead/rim interface than a 700x18 tire at 150 psi.

Hoop stress in a cylindrical pressure vessel is PR/T where P is
pressure, R is the cylinder radius and T is the thickness of the
material. Since we're concerned about force and not stress (which is
force/area), we can dispense with the denominator. This leaves us with
PR.

For an 18mm (0.009 m radius) tire pumped to 150 psi (1.03 megaPascals)
we get a force of 9270N per unit length*,

For a 37 mm (0.0185 m radius) tire pumped to 85 psi (0.59 MPa) we get a
force of 10,915N per unit length--obviously, a larger force.

When one considers a 23mm tire pumped to 115 psi (perhaps the most
common numbers), we get a result of 9118N per unit length.

This calculation incorporates a number of assumptions. I've assumed
that nominal tire width is actual width and that toroidal pressure
vessels (i.e., tires) operate exactly like cylindrical pressure
vessels. However, the forces I've listed should be pretty accurate on a
relative scale.

The point is that low-pressure fat tires can and do exert higher forces
on rims at the bead interface than do high-pressure skinny tires.

This is a very strange failure to me. I'll be interested to hear what
the cause was.

Cheers,

Jason

* N.B.: A Pascal is a unit of pressure, specifically, a force of one
Newton per square meter. Since P*R is (N/m^2)*m, the unit of radius
cancels with one of the units of area, yielding force (Newtons) per
meter.

Quoted message said:

Quoted message said:

Quoted message said:

[email hidden] wrote:
> On 7 Jun 2006 08:08:23 -0700, [email hidden] wrote:
>
> >How many of you would put an identical wheel/tire/pressure in as a
> >replacement and continue riding?
>
> Dear D.,
>
> I wouldn't put a 37mm tire on a rim recommended for no more than 28mm
> and 117 psi and then blow it up to an estimated 80-85 psi,
> particularly if I weighed 275 lbs.
>
> I've heard of a case where the wheel failed catastrophically within
> 500 miles on smooth pavement when this was done.
>
> Cheers,
>
> Carl Fogel

How about a 28mm tire?

Dear D.,

I'd happily put a 28mm tire on a rim rated for that width with no more
than 117 psi--and inflate it to about 100 psi or less. A recommended
maximum is a warning, not an invitation to see what happens.

In any case, the destroyed rim was wearing a 37mm tire inflated to an
estimated 80-85 psi when it abruptly tore itself in half after only
500 miles.

That 37mm is 32% beyond the CXP33's maximum recommended width.

What could be a more impressive and dramatic illustration that Mavic
was right about those rim limits? Or that wider tires exert more
leverage on rims?

Cheers,

Carl Fogel

And weighing 275 pounds you would ride happily into the sunset with a
28mm at 117 psi. Never a 2nd thought?

Dear D.,

You may have missed my reply:

Quoted message said:

Quoted message said:

I'd happily put a 28mm tire on a rim rated for that width with no more
than 117 psi--and inflate it to about 100 psi or less. A recommended
maximum is a warning, not an invitation to see what happens.

I've missed even plainer replies, so don't worry about it.

Cheers,

Carl Fogel

jim beam said:

Benjamin Lewis said:

I see what appears to be somewhat diffuse reflections of the spokes on
the rim in the third photo, which might be mistaken for bulging.

no mistake. the anodizing clouds where the rim deforms, hence the
"diffuse reflections".

Heh. Nice try.

--
Benjamin Lewis

Benjamin Lewis said:

jim beam said:

Benjamin Lewis said:

I see what appears to be somewhat diffuse reflections of the spokes on
the rim in the third photo, which might be mistaken for bulging.

no mistake. the anodizing clouds where the rim deforms, hence the
"diffuse reflections".

Heh. Nice try.

eh? so how much experience do you have with anodized surfaces and the
effects of deformation then ben? don't be coy.

jim beam said:

Benjamin Lewis said:

jim beam said:

Benjamin Lewis wrote:

> I see what appears to be somewhat diffuse reflections of the spokes on
> the rim in the third photo, which might be mistaken for bulging.
>

no mistake. the anodizing clouds where the rim deforms, hence the
"diffuse reflections".

Heh. Nice try.

eh? so how much experience do you have with anodized surfaces and the
effects of deformation then ben? don't be coy.

Why bother? Anyone who chooses to do so may view the photos for themselves.

--
Benjamin Lewis

[email hidden] wrote in
news:[email hidden]:

Quoted message said:

I suggest the rider needs a 500+ g rim, such as at minimum an Ambrosio
Evolution (480g, 13.5mm

Quoted message said:

ERTRO width, <http://www.ambrosiospa.com/cerchi_corsa.htm>😉, much
better an Ambrosio Keba (610g, 18mm ERTRO width,
<http://www.ambrosiospa.com/touring.htm>😉.

Hi! I'm the clydesdale whose Mavic blew up, instigating this thread.
I'm planning on having all my wheels rebuilt with different rims (I'm
scared of those Mavics now...). I'm not familiar with Ambrosio rims.
I note that Ambrosio offers multiple "touring" rims with wider
profiles. What differences are there between the different Ambrosio
touring rims, and which is the strongest?

Thanks!

Not an answer to your question, but another vote for Ambrosio. I weigh
240 and my daily commuter wheels are Ambrosio Excursions, which are the
same rim as the Evolution, but without the machined sidewalls. As a
consequence, they're slightly heavier (510g vs 480g) but that material's
in the sidewall where you need it. It's also socketed for better
distribution of spoke tension than single- or non-eyeleted rims.

I run them with 28mm Continental GP4Season tires @ 90-105psi. I've also
had 32mm Kenda Kwick cyclocross tires on them at around 55-60psi.

I've put close to 1000 miles on them since I built them in February, and
when I had the rear tire off to change a flat this weekend, I threw it
in the truing stand to touch it up. I was astonished that it was still
perfectly true, since I hadn't looked at it since I built it. Threw the
front in the stand, same thing. Nice wheels.

Booker C. Bense said:

... There are some interesting comments in there from
the wheel builder. He claims to have used a tensionmeter
and the wheel was within Mavics spoke tension tolerances
(ie. under 100kgs ). This paraphased comment I found puzzling.

"The cxp33 was the strongest rim we could find."

My guess was he didn't look too hard.

Uh, yeah. Maybe the strongest he could find in the stockroom that
afternoon?
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.