Ksyrium rim cracks

whocares writes-

sounds like you do BUT-<< after sunday race i noticed that on my rear ksyrium wheel rim cracked in 2
drive side spokes which are next to each other.. I'll post pics later.. By the way i weight 225
lbs.. And use them as race-only wheelset.. I ahad them for 1 year.. and now this.. >><BR><BR>

<< I was wonder if mavic will warranty the whole wheel or just a rim..

Quoted message said:

Quoted message said:

<BR><BR>

If < Iyear old and you have proof you are the original purchaser, they will rebuild them, new
rim/spokes-Takes about 3 weeks...if more than a year, rebuild is about $275...

Your weight has nothing to do with them cracking...

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 vecchios.comvecchios.comOpen ↗ "Ruote convenzionali costruite eccezionalmente bene"

Hello Peter!

Well, i guess my weight has something to do with it, since, my regular training 36 spoke rear
wheel (campy montreal 76 rim 36 spokes , d/a hubs, 14g spokes) cracked at nipple eyelets for 2nd
time now..

First time after it was hand-buld, it cracked in 4 month, and we thought it is because of
stress-relive (sheldon brown method) of the spokes.. So they replaced the rim.. and again , i have
hairline cracks all over the rim..

As far as weight goes i think it is detrimental, that weight and accelerations put loads of stress
on wheels, so i bet 150lbs riders will have much fewer problems with wheels then 225 lbs rider..

Thanks for the info!

Alexei

(Qui si parla Campagnolo) said:

whocares writes-

sounds like you do BUT-<< after sunday race i noticed that on my rear ksyrium wheel rim cracked in
2 drive side spokes which are next to each other.. I'll post pics later.. By the way i weight 225
lbs.. And use them as race-only wheelset.. I ahad them for 1 year.. and now this.. >><BR><BR>

<< I was wonder if mavic will warranty the whole wheel or just a rim..

Quoted message said:

Quoted message said:

<BR><BR>

If < Iyear old and you have proof you are the original purchaser, they will rebuild them, new
rim/spokes-Takes about 3 weeks...if more than a year, rebuild is about $275...

Your weight has nothing to do with them cracking...

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 vecchios.comvecchios.comOpen ↗ "Ruote convenzionali costruite eccezionalmente bene"

"Alexei Pavlov" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Hello Peter!

< snip >

Quoted message said:

As far as weight goes i think it is detrimental, that weight and accelerations put loads of stress
on wheels, so i bet 150lbs riders will have much fewer problems with wheels then 225 lbs rider..

I weigh less than 150lbs and have had the same problem twice - both times with 32-spoke Open Pro
rims. In my case I suspect it's because the wheels were badly built but I don't know for sure.

Craig.

Are these cranks in the rim itself, or the anodizing? I've gone through quite a few Mavic MA-2's,
and Open 4s, never seen a rim crack from just riding or hard braking. -tom

"Craig." <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

"Alexei Pavlov" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Hello Peter!

< snip >

Quoted message said:

As far as weight goes i think it is detrimental, that weight and accelerations put loads of
stress on wheels, so i bet 150lbs riders will have much fewer problems with wheels then 225 lbs
rider..

I weigh less than 150lbs and have had the same problem twice - both times with 32-spoke Open Pro
rims. In my case I suspect it's because the wheels were badly built but I don't know for sure.

Craig.

Peter Chisholm said:

Your weight has nothing to do with them cracking...

Oh yes it does. The greater th cyclic stress change, the greater the greater the rate of fatigue
failures are. This IS a fatigue failure.

Jobst Brandt [email hidden] Palo Alto CA

Peter Chisholm said:

Your weight has nothing to do with them cracking...

Oh yes it does. The greater the cyclic stress change, the greater the rate of fatigue failures. This
IS a fatigue failure.

Jobst Brandt [email hidden] Palo Alto CA

Tom Nakashima said:

Are these cranks in the rim itself, or the anodizing? I've gone through quite a few Mavic MA-2's,
and Open 4s, never seen a rim crack from just riding or hard braking.

If the cracks are visible, they are in the metal, regardless of anodizing. The MA-2 may not have
cracked but had you used the identical rim with black anodizing, you would most likely had cracks.
That rim would have been a MAVIC G-40 rim.

Jobst Brandt [email hidden] Palo Alto CA

Alexei Pavlov said:

Hi!

Quoted message said:

after sunday race i noticed that on my rear ksyrium wheel rim cracked in 2 drive side spokes which
are next to each other.. I'll post pics later.. By the way i weight 225 lbs.. And use them as
race-only wheelset.. I ahad them for 1 year.. and now this..

Quoted message said:

I was wonder if mavic will warranty the whole wheel or just a rim..

Quoted message said:

Alexei

Welcome to the world of planned obsolescence. There is a good reason why some people think the
"Rivendell" way is the right way to build bicycles. All components should be simple. All should be
interchangeable. All should be offered in the aftermarket. All should be affordable to replace. If
this were a normal set of wheels you'd be talking about a $100 repair ($60 for mavic open pro, $40
to relace it.)

sorry for your misery but i'd recommend going with a normal wheel rather than paying the $275 to get
the fragile high tech wheel put back into its original fragile state.

- Don Gillies San Diego, CA

A little confused now, I know you said "most likely" and "may not have cracked." Mavic made two
similar rims, the MA-2 and the G-40, only the G-40 is black anodized and has more potential to
crack? So it is the anodizing which weakens the rim? If you can lead me to an FAQ or literature on
this I would love to read it.. Just curious, what happens when the rims crack? Can they collapse at
anytime? -tom

<[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Tom Nakashima said:

Are these cranks in the rim itself, or the anodizing? I've gone through quite a few Mavic
MA-2's, and Open 4s, never seen a rim crack from just riding or hard braking.

If the cracks are visible, they are in the metal, regardless of anodizing. The MA-2 may not have
cracked but had you used the identical rim with black anodizing, you would most likely had cracks.
That rim would have been a MAVIC G-40 rim.

Jobst Brandt [email hidden] Palo Alto CA

In article said:

Hello Peter!

Well, i guess my weight has something to do with it, since, my regular training 36 spoke rear
wheel (campy montreal 76 rim 36 spokes , d/a hubs, 14g spokes) cracked at nipple eyelets for 2nd
time now..

First time after it was hand-buld, it cracked in 4 month, and we thought it is because of
stress-relive (sheldon brown method) of the spokes.. So they replaced the rim.. and again , i have
hairline cracks all over the rim..

As far as weight goes i think it is detrimental, that weight and accelerations put loads of stress
on wheels, so i bet 150lbs riders will have much fewer problems with wheels then 225 lbs rider..

Next I would be going to a beefy stiff rim, like a CXP-33 with at least 32 spokes in back. You could
also try a mail-order guru wheelbuilder - if you do, start by asking them what they think is the
best wheel they can build for you.

--Paul

Tom Nakashima said:

A little confused now, I know you said "most likely" and "may not have cracked." Mavic made two
similar rims, the MA-2 and the G-40, only the G-40 is black anodized and has more potential to
crack? So it is the anodizing which weakens the rim? If you can lead me to an FAQ or literature on
this I would love to read it.. Just curious, what happens when the rims crack? Can they collapse
at anytime? -tom

Aaarch!!, not again 😉

groups.google.nlgroupsOpen ↗

290 hits
--
Marten

Tom Nakashima said:

A little confused now, I know you said "most likely" and "may not have cracked." Mavic made two
similar rims, the MA-2 and the G-40, only the G-40 is black anodized and has more potential to
crack? So it is the anodizing which weakens the rim?

The anodizing is brittle/hard. Cracks begin there. The anodizing molecules are very similar (high
coherency) in physical dimension to the underlying Al crystals, thus the two bond well and any
cracks in the brittle anodizing shell are propagated into the underlying Al crystals.

I just spoke with the plating shop here at the Stanford Linear Accelerator Center, they said they've
never seen cracks in the anodizing. We're going to run a test on .062" aluminum, have it black
anodized then bend it to see if cracks occur. Any suggestions for other test, we also have a
Rockwell hardness tester here. -tom

"gwhite" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Tom Nakashima said:

A little confused now, I know you said "most likely" and "may not have cracked." Mavic made two
similar rims, the MA-2 and the G-40, only the G-40 is

black

Quoted message said:

Quoted message said:

anodized and has more potential to crack? So it is the anodizing which weakens the rim?

The anodizing is brittle/hard. Cracks begin there. The anodizing

molecules are

Quoted message said:

very similar (high coherency) in physical dimension to the underlying Al crystals, thus the two
bond well and any cracks in the brittle anodizing

shell

Quoted message said:

are propagated into the underlying Al crystals.

Tom Nakashima said:

Quoted message said:

Quoted message said:

Are these cranks in the rim itself, or the anodizing? I've gone through quite a few Mavic
MA-2's, and Open 4s, never seen a rim crack from just riding or hard braking.

Quoted message said:

Quoted message said:

If the cracks are visible, they are in the metal, regardless of anodizing. The MA-2 may not have
cracked but had you used the identical rim with black anodizing, you would most likely had
cracks. That rim would have been a MAVIC G-40 rim.

Quoted message said:

A little confused now, I know you said "most likely" and "may not have cracked." Mavic made two
similar rims, the MA-2 and the G-40, only the G-40 is black anodized and has more potential to
crack? So it is the anodizing which weakens the rim? If you can lead me to an FAQ or literature on
this I would love to read it.. Just curious, what happens when the rims crack? Can they collapse
at anytime?

Crack generation is not a sudden event but a fatigue failure that take many thousands of stress
cycles (loaded wheel rotations) to develop. The cracks are especially easy to see on dark anodized
rims and it is the crazed surface of the anodizing that initiates crack development. It is much like
bending the knee having a scab. The hard, inelastic scab cracks and tears the redeveloping skin
beneath, causing bleeding. In contrast, after soaking the scab in water it can often be removed and
the knee bent without tearing the skin.

Anodizing is a hard and brittle ceramic coat that already is crazed from rolling the rim into a
hoop. Additional (mostly invisible) cracking occurs when sockets and eyelets are riveted into place.
These cracks can often be seen by strong illumination in a grazing incidence. The thicker the
anodizing, the greater the initial crack size.

aerade.cranfield.ac.ukES104.htmlOpen ↗

Jobst Brandt [email hidden] Palo Alto CA

Tom Nakashima said:

I just spoke with the plating shop here at the Stanford Linear Accelerator Center, they said
they've never seen cracks in the anodizing. We're going to run a test on .062" aluminum, have it
black anodized then bend it to see if cracks occur. Any suggestions for other test, we also have a
Rockwell hardness tester here.

Not really -- the anecdotal evidence of failures does indeed exist for anodized rims. I am not a
MatSci Eng, nor a Civil or Mech Eng. What I know is only based on a college course in MatSci Eng;
the rim failures are consistant with the basic idea I represented and learned in college. That is
the end of what I have to technically contribute, for the most part. The spoke holes are under
stress *cycles*, not just a single bend. So I suppose a test should simulate/replicate the real
world situation.

Kraig Willet has often posed the question whether a "thin" layer of anodizing for cosmetic reasons
(nice colors) really represents the level of problem of "thicker" anodizing. I believe it is a fair
question (because consumer taste does matter and a tradeoff may be a fair one in that regard), but
those who have more appropriate technically training than I have seem to shy away from this more
marginal case. I use the terms "thin" and "thick" because I am out of my field; someone else may be
able to quantify these ideas with ease. These thicknesses and any other issues must be replicated in
your tests/simulations.

Personally, I favor non-anodized rims because of the anecdotal evidence and my limited education in
the matter align. I will tolerate a very thin anodizing layer for my purchases, if things such as
price and overall design are otherwise in good order.

Alexei Pavlov said:

Well, I guess my weight has something to do with it, since, my regular training 36 spoke rear
wheel (Campy Montreal 76 rim 36 spokes , d/a hubs, 14g spokes) cracked at nipple eyelets for 2nd
time now..

Quoted message said:

First time after it was hand-built, it cracked in 4 month, and we thought it is because of
stress-relive (Sheldon Brown method) of the spokes... So they replaced the rim... and again , I
have hairline cracks all over the rim.

Quoted message said:

As far as weight goes I think it is detrimental, that weight and accelerations put loads of stress
on wheels, so I bet 150lbs riders will have much fewer problems with wheels then 225 lbs rider..

I think you would do far better with 1.8-1.6mm swaged spokes in a non anodized rim. The thicker the
spoke, the more concentrated the entire load becomes on two or so spokes. A well stress relieved
wheel with thin spokes is more durable than one with fat spokes. For one time loading, the wheel
with the heaviest spoke is stronger but collapsing wheels is not your problem.

Jobst Brandt [email hidden] Palo Alto CA

Tom Nakashima said:

I just spoke with the plating shop here at the Stanford Linear Accelerator Center, they said
they've never seen cracks in the anodizing. We're going to run a test on .062" aluminum, have it
black anodized then bend it to see if cracks occur. Any suggestions for other test, we also have a
Rockwell hardness tester here.

I think you'll need to specify depth and "hard anodized" to make a valid comparison. Cosmetic
anodizing can be made thin enough that it has essentially no effect on cracking much like the light
pink rims from Mavic.

Jobst Brandt [email hidden] Palo Alto CA

Tom Nakashima said:

I just spoke with the plating shop here at the Stanford Linear Accelerator Center, they said
they've never seen cracks in the anodizing. We're going to run a test on .062" aluminum, have it
black anodized then bend it to see if cracks occur. Any suggestions for other test, we also have a
Rockwell hardness tester here.

I know the Stanford ME department has a fatigue test rig (at least they used to). Fatigue tests are
usually done on round bar stock, but someone in the ME department could give you specifics. The
standard wisdom is that anodizing decreases fatigue life by abot 40%.
--
terry morse Palo Alto, CA terrymorse.combikeOpen ↗

what about silver anodized jobst? you never seem to acknowledge it's existance - even on your
precious ma2's.

jim beam

Quoted message said:

Tom Nakashima said:

I just spoke with the plating shop here at the Stanford Linear Accelerator Center, they said
they've never seen cracks in the anodizing. We're going to run a test on .062" aluminum, have it
black anodized then bend it to see if cracks occur. Any suggestions for other test, we also have a
Rockwell hardness tester here.

I think you'll need to specify depth and "hard anodized" to make a valid comparison. Cosmetic
anodizing can be made thin enough that it has essentially no effect on cracking much like the
light pink rims from Mavic.

Jobst Brandt [email hidden] Palo Alto CA