Rim Failure

"Mike Jacoubowsky" wrote: Fool me once, shame on you. Fool me twice,
shame on me. (clip)
^^^^^^^^^^^^^^^^^
Mike, you could also have mentioned how you, as a dealer, would react if a
certain product exhibited a higher than average failure rate. I'm sure
you don't fancy dealing with customers who come in saying, "I haven't had
this very long, and look what happened." You would stop stocking the
product.

Leo: Thanks for pointing that out. See, stay long enough in a newsgroup and
people answer for you, better than you would have done yourself!

But to be sure, dealers are often frustrated when calling a company about
the 3rd or 4th time you've seen something, and hearing "Well, that's the
first time we've heard of that." Fortunately, after you've been around a
while and cultivated relationships, you tend to get the real story, rather
than the line people are told so as not to alarm dealers. It's all in how
you respond to things. If a dealer sees a particular issue and calls up the
company, yells at them that the sky is falling and how can they make such
crappy product... yeah, the company is going to assume they're not the best
people to say "Yes, we've had some issues with that, we're working on a
solution, here's what you might try in the meantime."

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

Zog The Undeniable wrote:
Michael Press wrote:

Cracking like that should never happen. All I can say is
that companies with a grip on the market prefer to sell
rims that break. Making a light rim that does not break at
the spoke hole is well understood. Good rims have been
made for decades. There is no manufacturing-engineering
reason for making inferior rims. The reason to make
inferior rims is so that folks buy more rims at inflated
prices.

Applying Occam's Razor, it's more likely to be incompetent design. They
just didn't put enough metal in the right place and/or didn't test
thoroughly.


Aren't these the same Ritchey wheels Nashbar/Supergo were selling for
60+% off a few months ago? Perhaps now we know why......

In article
,
"Mike Jacoubowsky" wrote:

There is no manufacturing-engineering
reason for making inferior rims. The reason to make
inferior rims is so that folks buy more rims at inflated
prices.

Fool me once, shame on you. Fool me twice, shame on me.

Even the dumbest bicycle component company isn't stupid enough to think that
people are likely to pay $$$ to replace equipment that failed before its
time with more from the same company. Sure, some people may, but a whole lot
of people are going to be buying something from a competing company. The
only people who would benefit from making product that consistently failed
earlier than it should would be those with a near-monopoly, and that doesn't
exist in the wheel-goods section of the marketplace. Lots and lots and lots
of options. And no, there's not a conspiracy among the various companies to
all make shoddy product so they sell more. That's giving them way too much
credit.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com


"Michael Press" wrote in message
...
In article
.com,
wrote:

I bought a set of brand new Ritchey Zero Comp road wheels, and the rear
developed cracks around the spoke holes within a few months. I did
maybe about 50% of my milage on these wheels.

A photo is here :

http://www.midweekclub.com/temp/rimcrack.jpg

About half the spoke holes for the drive side spokes have cracks like
these. The rims have a thin silver anodizing and there are no rim
eyelets. The rim is an offset design, to reduce the left side/right
side tension difference.

I didn't mess with the spoke tensions until the spokes became very
loose and I had to retension the wheel myself.

Is there an explanation of why this happened ? and what rim should I
replace it with ?

Cracking like that should never happen. All I can say is
that companies with a grip on the market prefer to sell
rims that break. Making a light rim that does not break at
the spoke hole is well understood. Good rims have been
made for decades. There is no manufacturing-engineering
reason for making inferior rims. The reason to make
inferior rims is so that folks buy more rims at inflated
prices.

I do not seek conspiracies. Inferior goods at inflated
prices can, for instance, be the result of a highly
leveraged buy-out by people who do not know, or care,
anything about the manufacturer they bought. All they know
is getting money. One way is to make the products more
cheaply, and consequently less well. As you say, a
manufacturer making bad products, or products selling for
much more than they are intrinsically worth, will
eventually fail; but how long does it take? Mavic is still
making money.

--
Michael Press

wrote:
I bought a set of brand new Ritchey Zero Comp road wheels, and the rear
developed cracks around the spoke holes within a few months. I did
maybe about 50% of my milage on these wheels.


your riding style - (spin or mash), kind of roads you ride etc. can
explain this. Also, spoke count is a factor. Also, you say you tensioned
it when it came loose - at that time you didn't any cracks did you ?? I
wonder why it became loose in the first place - was it undertensioned
when you bought it ? or after you hit some pot hole or something ?? How
true was the wheel when you bought it ? how often did you have to true
it before you got the point to notice that the spokes were loose...

As stated by prev. posters, each rim has a specific tension, exceeding
that tension is a sure way of cracking the rims. You can measure the
tension (or get LBS to do it) and see if it is beyond the specifications
for that rim.

+ravi

A photo is here :

http://www.midweekclub.com/temp/rimcrack.jpg

About half the spoke holes for the drive side spokes have cracks like
these. The rims have a thin silver anodizing and there are no rim
eyelets. The rim is an offset design, to reduce the left side/right
side tension difference.

I didn't mess with the spoke tensions until the spokes became very
loose and I had to retension the wheel myself.

Is there an explanation of why this happened ? and what rim should I
replace it with ?

-Amit

Michael Press writes:

I bought a set of brand new Ritchey Zero Comp road wheels, and the
rear developed cracks around the spoke holes within a few months.
I did maybe about 50% of my mileage on these wheels.

A photo is here :

http://www.midweekclub.com/temp/rimcrack.jpg

About half the spoke holes for the drive side spokes have cracks
like these. The rims have a thin silver anodizing and there are no
rim eyelets. The rim is an offset design, to reduce the left
side/right side tension difference.

I didn't mess with the spoke tensions until the spokes became very
loose and I had to re-tension the wheel myself.

Is there an explanation of why this happened? and what rim should
I replace it with?

Cracking like that should never happen. All I can say is that
companies with a grip on the market prefer to sell rims that break.
Making a light rim that does not break at the spoke hole is well
understood. Good rims have been made for decades. There is no
manufacturing-engineering reason for making inferior rims. The
reason to make inferior rims is so that folks buy more rims at
inflated prices.

It doesn't seem to be a cost reason either because socketed rims cost
less than most rims that replaced them. That sockets were necessary
was discovered 50 years ago when most major manufacturers used sockets
in their tubular rims and then offered rims like the MA-2 when
clinchers became the mainstream.

I was greatly disappointed when hard anodized rims showed up again
when socketed rims were discontinued with a big splash from Mavic
about how welded, machined, anodized rims were improving bicycling.

So here we are discussing cracked rims and reduced spoke tension,
things that weren't issues prior to all these NEW rims.

Jobst Brandt

"G.T." wrote in message
...
jim beam wrote:
wrote:

I bought a set of brand new Ritchey Zero Comp road wheels,
and the rear
developed cracks around the spoke holes within a few months.
I did
maybe about 50% of my milage on these wheels.

A photo is here :

http://www.midweekclub.com/temp/rimcrack.jpg

About half the spoke holes for the drive side spokes have
cracks like
these. The rims have a thin silver anodizing and there are
no rim
eyelets. The rim is an offset design, to reduce the left
side/right
side tension difference.

I didn't mess with the spoke tensions until the spokes
became very
loose and I had to retension the wheel myself.

Is there an explanation of why this happened ? and what rim
should I
replace it with ?
-Amit

when you retensioned, what tension level did you use? did
you use a
tensiometer? or "tension as high as the rim will bear"?

bottom line, that looks like classic over-tension. there is
no reason
to exceed the spoke tension specified by the rim
manufacturer.

And just how slack would he have to run his spokes to avoid
this? Slack
enough that he would constantly be straightening his wheels due
to poor
spoke tension?

It's an off-center rim on a pre-built wheel. Ritchey is the
builder, and you would think it knows what tension to use on its
own rim. If it is over-tensioning, then it is not the OP's
fault. Really, though, I remember reports years ago about these
rims cracking. I think this problem is old news. -- Jay Beattie.

Ravi who? writes:

I bought a set of brand new Ritchey Zero Comp road wheels, and the
rear developed cracks around the spoke holes within a few months. I
did maybe about 50% of my mileage on these wheels.

Your riding style - (spin or mash), kind of roads you ride etc. can
explain this. Also, spoke count is a factor. Also, you say you
tensioned it when it came loose - at that time you didn't any cracks
did you? I wonder why it became loose in the first place - was it
under-tensioned when you bought it? Or after you hit some pot hole
or something? How true was the wheel when you bought it? How
often did you have to true it before you got the point to notice
that the spokes were loose...

Oh great. Here we are back at the victim is at fault. Maybe you can
explain how gear selection affects rim cracking considering that
torque pulses are smaller the higher the gear used. Recall that
socketed rims were used on roads in the Alps before they were paved
and European cities had many cobble stone streets. We did not have
rim cracking then so how do you suggest we restrict our bicycling to
bow to appease the rim gods. I hope you are aware that the radial
load of the loaded bicycle coasting along on a road is the highest
stress to which rims are subjected.

As stated by previous posters, each rim has a specific tension,
exceeding that tension is a sure way of cracking the rims. You can
measure the tension (or get LBS to do it) and see if it is beyond
the specifications for that rim.

Oh! And how did someone arrive at that "correct" tension? As I said,
with socketed rims, wheels were tensioned to the limit of rim hoop
compression. We didn't have no steenkin cracks.

Why do you appoint yourself as apologist for the manufacturers who are
cheating their market by leaving out essential rim components?

Jobst Brandt

wrote:
There is no manufacturing-engineering
reason for making inferior rims. The reason to make
inferior rims is so that folks buy more rims at inflated
prices.

Mike Jacoubowsky wrote:
Fool me once, shame on you. Fool me twice, shame on me.
Even the dumbest bicycle component company isn't stupid enough to think that
people are likely to pay $$$ to replace equipment that failed before its
time with more from the same company. Sure, some people may, but a whole lot
of people are going to be buying something from a competing company. The
only people who would benefit from making product that consistently failed
earlier than it should would be those with a near-monopoly, and that doesn't
exist in the wheel-goods section of the marketplace. Lots and lots and lots
of options. And no, there's not a conspiracy among the various companies to
all make shoddy product so they sell more. That's giving them way too much
credit.

I had an Italian manufacturer visit here in early December.
I showed him one of his 1970 saddles on the bike I ride
every day. He looked me right in the eye and said "If we had
kept making things that lasted that long we would be out of
business". Direct quote, take it as you will.

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

A Muzi wrote:
wrote:
There is no manufacturing-engineering
reason for making inferior rims. The reason to make
inferior rims is so that folks buy more rims at inflated
prices.

Mike Jacoubowsky wrote:
Fool me once, shame on you. Fool me twice, shame on me.
Even the dumbest bicycle component company isn't stupid enough to think that
people are likely to pay $$$ to replace equipment that failed before its
time with more from the same company. Sure, some people may, but a whole lot
of people are going to be buying something from a competing company. The
only people who would benefit from making product that consistently failed
earlier than it should would be those with a near-monopoly, and that doesn't
exist in the wheel-goods section of the marketplace. Lots and lots and lots
of options. And no, there's not a conspiracy among the various companies to
all make shoddy product so they sell more. That's giving them way too much
credit.

I had an Italian manufacturer visit here in early December.
I showed him one of his 1970 saddles on the bike I ride
every day. He looked me right in the eye and said "If we had
kept making things that lasted that long we would be out of
business". Direct quote, take it as you will.



Wow, that's right to the point. Most of the newer stuff doesn't last
that long, but most people don't care 'cuz the marketing machinery does
it's level best to make you feel anything more than 3-4 years old is
hopelessly outdated anyway.

wrote:
Ravi who? writes:


I bought a set of brand new Ritchey Zero Comp road wheels, and the
rear developed cracks around the spoke holes within a few months. I
did maybe about 50% of my mileage on these wheels.


Your riding style - (spin or mash), kind of roads you ride etc. can
explain this. Also, spoke count is a factor. Also, you say you
tensioned it when it came loose - at that time you didn't any cracks
did you? I wonder why it became loose in the first place - was it
under-tensioned when you bought it? Or after you hit some pot hole
or something? How true was the wheel when you bought it? How
often did you have to true it before you got the point to notice
that the spokes were loose...


Oh great. Here we are back at the victim is at fault. Maybe you can
explain how gear selection affects rim cracking considering that
torque pulses are smaller the higher the gear used.

ok...

Recall that
socketed rims were used on roads in the Alps before they were paved
and European cities had many cobble stone streets.

which has /nothing/ to do with the point above.

We did not have
rim cracking then so how do you suggest we restrict our bicycling to
bow to appease the rim gods.

and we had different rims, but don't let a minor detail like that bother
you.

I hope you are aware that the radial
load of the loaded bicycle coasting along on a road is the highest
stress to which rims are subjected.

except for where lateral loads are experienced, you know, like those
where [ye gods] you get out of the saddle.



As stated by previous posters, each rim has a specific tension,
exceeding that tension is a sure way of cracking the rims. You can
measure the tension (or get LBS to do it) and see if it is beyond
the specifications for that rim.


Oh! And how did someone arrive at that "correct" tension? As I said,
with socketed rims, wheels were tensioned to the limit of rim hoop
compression. We didn't have no steenkin cracks.

like we don't need no "steenkin" tensiometer to make a technical
analysis like "tension as high as the rim will bear"? despite that fact
that over-tension significantly increases propensity to taco and does
nothing to increase rim strength?


Why do you appoint yourself as apologist for the manufacturers who are
cheating their market by leaving out essential rim components?

Jobst Brandt

glad to see good manners are back in fashion again jobst. and keep up
the informative, analytical, relevant contributions.