Danger from CF rims

On 12/3/2018 1:52 PM, wrote:
On Monday, December 3, 2018 at 10:01:13 AM UTC-8, AMuzi wrote:
On 12/3/2018 10:26 AM, wrote:
On Monday, December 3, 2018 at 6:12:54 AM UTC-8, wrote:
On Monday, December 3, 2018 at 1:23:55 AM UTC+1, jbeattie wrote:
On Sunday, December 2, 2018 at 3:09:21 PM UTC-8, John B. slocomb wrote:
giant snip

Apparently you are unfamiliar with this foreign concept - United States Postal Service. Exactly what you would have a dealer using after charging you as much as 10 times more than I paid. But I'm sure you're rolling in cash and that means nothing to you.

Goodness! We were talking about the alleged "fact" that you posted
that "Most carbon rims are made in China from prepreg from Japan" and
I pointed out that carbon rims are also made by U.S. companies and
that their warranty is for 5 years.

Now you are off on a on a trip through the intricacies of the USPS and
apparently complaining that U.S. made wheels are more costly then the
cheap Chinese wheels that you bought.

The last time I corrected your fantasies you changed the subject to
India and now it is (apparently) how impoverish you are.

Wake up Tom, buying stuff because it is cheap and having it fail is
not saving money.

With his history of CF disasters, TK should be buying the most reliable products on the market sold by domestic sellers with domestic insurers. Try recovering a personal injury settlement or judgment from a Chinese manufacturer who sells direct -- or its insurer in China. Justify the increased price as an insurance premium.

That is also what surprized me. How can a person with that history and the following rants about CF buy cheap Chinese CF stuff. Unbelievable. You can buy Pinnarello frame for 350 euro, looking exactly the same as the originals a probably used in the same moulds, but the measurements showed completely different values. With CF is all about lay ups, used preps and quality control. The fact that something is produced in the same country (China) doesn't mean anything. I stay far far far away from CF with an unknown pedigree as you call it. Tom should do the same IMO. CF rims for clinchers are difficult hence their price, CF rims for tubeless even more difficult and than buying cheap Chinese stuff? WTF is he thinking...




Assuming that the wheels TK bought were unbranded versions of reputable wheels made in a Chinese factory, that means that the factory was knocking them off and stealing its customer's IP -- not something we want to promote. Assuming that the customer is actually policing its IP and its factory, then the knock-off is probably coming from a different factory and is of unknown quality. Now, there have been some very good knock-offs. Phil Knight busted a factory for knocking off Nikes and then hired them because the knock-offs were so good. However, there is no way of knowing in advance what knock-offs are really good and which aren't -- and unlike shoes, you can't see the "stitching" and materials and workmanship of a CF rim. For all you know, there are giant voids and a ****ty lay-up. OTOH, it might be O.K. stuff, but if I had landed on my head a bunch of time because of broken CF bits, O.K. would not be good enough.

+1

Lou

Lou - Where did you see this bike made out of Pinarello molds that had completely different measurements? How did you measure it? My guess is that as usual it is an urban myth.

That reminds me of that video I referenced that showed a high capacity wheel factory in China and someone here referencing a wheel building plant here which had technology 40% of the Chinese version. Almost all of the carbon fiber frames are built in China, Taiwan or India. Do you think that Trek is built here? Have you looked at the C64 Colnago? Knowing what I know not I wouldn't touch that Italian made POJ.

Chinese engineering is as good as anywhere else. Hell, most of their engineers go through American universities. The only problem is when they cut corners to sell cheaper. They are not cutting any corners on the clincher wheels since they are the same wheels used by several British and French "manufacturers" who improve their product by adding a decal. For instance - MAVICs are built in China.

I was totally against CF after several failures I observed personally but after extensive research and actually talking to engineers working with CF at Boeing I changed my opinion. It ain't the material, but the use of the material. Like any other material it has design limitations and if you remain within those limits you're fine.

The tubeless wheels aren't inherently bad designs, they simply do not have the quality control for that specific use. Do you suppose they just released those things without testing them? If they were breaking all the time their test lot would have shown it. But the difference between a test lot and a production lot can be worlds apart.



"Chinese engineering is as good as anywhere else. Hell, most
of their engineers go through American universities."

I do not believe either of those are true.

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

Andrew - do you have some big-time engineering universities around where you live? MIT? All you have to do is ask them.

Now we get a WHOLE lot of shoddy Chinese products but it almost entirely isn't from the engineering but from the marketing and management cutting corners.

My impression has been that Chinese companies are notorious for piracy,
copying, intellectual property violations, etc. I'm sure that China has
many super-competent engineers. I'm also sure they have many engineers
that are far less competent, and that they have companies that don't
employ any engineers. They just have workers who are halfway decent at
copying someone else's design and making it look good. I'm betting that
there are hundreds of such companies, mostly tiny, flooding markets with
products with surprisingly low prices.

If someone in any country wanted to copy a top quality aluminum alloy
rim, they could do it pretty easily. Extrusion dies are inexpensive and
extruding is a mature, well understood technology. Get yourself an
extrusion press, a furnace or billet heater, a decent die maker, and
you're in business. Bending and drilling are all that remain. The only
way to screw up is to use the wrong alloy (and perhaps heat treatment,
for some rims).

Carbon fiber is different. It's a much more finicky process, there can
be much more variation in the fiber, the resin and the layup. And
quality control is much more sophisticated than for extrusion.

I'm not in any way saying Chinese CF products are all bad. But I'll bet
heavily that a higher percentage of Chinese CF products are junk,
compared to American CF products.

--
- Frank Krygowski

On 12/3/2018 3:54 PM, jbeattie wrote:

It's like the $12 angle grinder from Harbor Freight. At some point, the price is a giant red flag.

I do think there are some bargains to be had. Joerg likes the Chinese brake pads, and there are somethings sold by the Chinese that you just can't get elsewhere -- like these: https://tinyurl.com/y93bccln I'd buy things like a low-use tool e.g. a bleed kit or something for a one-off hub bearing job -- although I'd probably buy US/German/Japanese bearings.

I'd be interested in hearing about true Chinese bargains.

Interestingly enough, my $12 angle grinder from Harbor Freight has
worked out perfectly for me! So there's that.

More disclosu I bought it for one job, cleaning up welds on a set of
ornamental balcony and stair rails I was building. So it worked well
grinding hundreds of welds. It's been used only occasionally since.
(Even more disclosu I don't remember the price. Maybe it was more
than $12.)

I got some Vuelta wheels cheap from Nashbar for my commuter, and they're probably a standard Chinese factory item -- a mildly aero 28 hole aluminum rim, aero spokes and a Formula-ish hub. Same old same old -- decent but nothing earth shattering. Spending more might have gotten me a better set of bearings or freehub, but maybe not. On sale, they were a true bargain.

And we should try to remember that for almost anything regarding
non-electric bicycles, we've long since been deep into diminishing
returns. If your commuter's hubs had better bearings, could you really
tell while slogging uphill in Portland rain? If the spokes or rims were
more aero, would you notice it in your effort expended or in reduced
commuting time? Probably not.


--
- Frank Krygowski

On 12/3/2018 4:27 PM, Frank Krygowski wrote:
On 12/3/2018 12:54 PM, AMuzi wrote:
On 12/2/2018 9:25 PM, Frank Krygowski wrote:
On 12/2/2018 7:17 PM, wrote:
On Sunday, December 2, 2018 at 3:09:21 PM UTC-8, John B.
slocomb wrote:

Goodness! We were talking about the alleged "fact" that
you posted
that "Most carbon rims are made in China from prepreg
from Japan" and
I pointed out that carbon rims are also made by U.S.
companies and
that their warranty is for 5 years.

Now you are off on a on a trip through the intricacies of
the USPS and
apparently complaining that U.S. made wheels are more
costly then the
cheap Chinese wheels that you bought.

The last time I corrected your fantasies you changed the
subject to
India and now it is (apparently) how impoverish you are.

Wake up Tom, buying stuff because it is cheap and having
it fail is
not saving money.

John, is there something about "most" you don't
understand? I said MOST carbon rims. And where did you get
the reliability data on American made tubeless carbon rims?

What you are saying that if I'm willing to spend 5 times
as much I will get a reliable rim when the vast majority
of manufacturers don't seem to share your opinion and have
changed back to aluminum rims with carbon fairings.

I am curious as to why you would make patently false
claims for no other reason than to criticize a posting I
placed here to warn people off.

I'm curious why non-racers buy carbon rims in the first
place.



Because they want carbon rims probably. Who knows why
anyone wants anything? It's not always Veblen.

Not always...

But I don't consider the "why want that?" question to be
unanswerable. Certainly the justifications are sometimes
multiple and/or complicated, but that doesn't mean it should
all be labeled unknowable.

And I think it is worth remembering that lots of our
purchasing is heavily influenced by advertising and "me too"
culture. As someone recently noted, there was a time not
_that_ long ago when people didn't buy shampoo (they just
used soap)... let alone mouthwash, lip gloss, cowboy boots,
SUVs, neckties, fidget spinners, AR-15s, Fitbits.

Bicycling is far from immune from those forces.



Certainly products have different features! My girlfriend's
homestead still has a completely worn out 1892 Winchester
and the same basic design, also seriously worn, from 1962
also chambered .30Win. Did those reliably feed her ancestors
down to her younger siblings? Yep. My AR15 in .223 is
lighter, easier to strip/clean and every little piece of it
from the smallest spring to a new barrel is available from
literally hundreds of vendors at a range of price/quality.
Nothing wrong with a lever action .30Win, and the old irons
are just beautiful on the wall, but if you want something
to actually use, AR15 beats it in every way.

And so to carbon rims. Do I need a set? well, uh, no I
don't. But that doesn't mean someone else looking for
lighter weight wouldn't find a pair of Bora attractive.
Having been in this business a very long while, people make
purchase decisions in complex ways that sometimes the buyer
herself doesn't fully understand or acknowledge. There's
also general human progress, in that without oddball
designers and screwy consumers we would never have real
innovation. That has value and a soviet style planned
economy suffers the lack of it.

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

On Mon, 3 Dec 2018 08:02:14 -0800 (PST), wrote:

On Monday, December 3, 2018 at 3:06:42 AM UTC-8, John B. slocomb wrote:
On Sun, 2 Dec 2018 16:17:32 -0800 (PST), wrote:

On Sunday, December 2, 2018 at 3:09:21 PM UTC-8, John B. slocomb wrote:

Goodness! We were talking about the alleged "fact" that you posted
that "Most carbon rims are made in China from prepreg from Japan" and
I pointed out that carbon rims are also made by U.S. companies and
that their warranty is for 5 years.

Now you are off on a on a trip through the intricacies of the USPS and
apparently complaining that U.S. made wheels are more costly then the
cheap Chinese wheels that you bought.

The last time I corrected your fantasies you changed the subject to
India and now it is (apparently) how impoverish you are.

Wake up Tom, buying stuff because it is cheap and having it fail is
not saving money.

cheers,

John B.

John, is there something about "most" you don't understand? I said MOST carbon rims. And where did you get the reliability data on American made tubeless carbon rims?

What you are saying that if I'm willing to spend 5 times as much I will get a reliable rim when the vast majority of manufacturers don't seem to share your opinion and have changed back to aluminum rims with carbon fairings.

I am curious as to why you would make patently false claims for no other reason than to criticize a posting I placed here to warn people off.

"Patently false claims"? Which ones are those? The one about carbon
rims being made in the U.S.? With a 5 year Warrantee?

Tell me john - what personal experience have you had with carbon rims? What the hell makes you believe that "American made" carbon rims have any different problems with the others? You know nothing about this and simply shoot your mouth off to feel in some manner superior and what that is for I have no idea. Didn't your mother cuddle you enough in your crib?

You said, "I am curious as to why you would make patently false
claims" and when I ask you which of my claims are "patently false" you
don't answer. I can only assume that you can't, which in turn would
seem to indicate that you are prone to saying things that just aren't
true so that when questioned your only reaction is to change the
subject. Or be caught in yet another lie.

As for composite work, I built composite boats and boat parts for
approximately 10 years so yes I do know a bit about the subject....

But I suppose you will now claim that boats and parts aren't round so
it isn't the same thing. Or will you fly off to another subject?


cheers,

John B.

On Mon, 3 Dec 2018 08:04:41 -0800 (PST), wrote:

On Monday, December 3, 2018 at 3:19:19 AM UTC-8, John B. slocomb wrote:
On Sun, 2 Dec 2018 16:34:26 -0800 (PST), wrote:

On Sunday, December 2, 2018 at 12:22:55 PM UTC-8, AMuzi wrote:

Yes, tubular rims are different. That was not my question.

How does a rim experience different forces with the same
tire at the same pressure either with latex slop inside or a
butyl tube?

Or, again same tire, how does one rim with an airtight rim
liner experience different forces from a rim with a
permeable rim liner?

Which forces? How different?

Inquiring minds want to know.

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

Andrew, I thought I was pretty clear on that. I expect you have access to a clincher only and a bi" wheel so that you can see the rather major differences in the construction.

The clincher rim is semi-circular from bead to bead while the tubeless rim has a longer drop down the inside top of one side to aid sealing by increasing the area of the bead. It then has a square shelf and then again drops down into the center well while the other side is a mirror copy.

The forces are completely different.

Because of the shape of the inside of the clincher most of the forces push UP away from the well and the side thrust is only enough to make the bead stick.

On the tubeless most of the forces are sideways to seal the tire against the rim. The air in the tire only acts as a pneumatic cushion.

So while they seem the same they are quite differet

Tom, I hate to tell you but the pressure in a closed container is
equal on all inner surfaces of the container. You can't have a tire
that exerts most of it's force toward the sidewalls as you seem to be
saying.

Old Bobby Boyle figured all this out back in sixteen-hundred and
something.

And I hate to tell you this but you're as usual full of crap. Air pressure though equal in all directions effects its container differently for different shapes. But that's probably beyond you.

You mean that if a container is, lets say, round on one side and
square on the other that the pressure is somehow different on each
end?

Or maybe you just don't know what you are talking about?

cheers,

John B.

On 12/3/2018 6:27 PM, AMuzi wrote:
On 12/3/2018 4:27 PM, Frank Krygowski wrote:
On 12/3/2018 12:54 PM, AMuzi wrote:
On 12/2/2018 9:25 PM, Frank Krygowski wrote:
On 12/2/2018 7:17 PM, wrote:
On Sunday, December 2, 2018 at 3:09:21 PM UTC-8, John B.
slocomb wrote:

Goodness! We were talking about the alleged "fact" that
you posted
that "Most carbon rims are made in China from prepreg
from Japan" and
I pointed out that carbon rims are also made by U.S.
companies and
that their warranty is for 5 years.

Now you are off on a on a trip through the intricacies of
the USPS and
apparently complaining that U.S. made wheels are more
costly then the
cheap Chinese wheels that you bought.

The last time I corrected your fantasies you changed the
subject to
India and now it is (apparently) how impoverish you are.

Wake up Tom, buying stuff because it is cheap and having
it fail is
not saving money.

John, is there something about "most" you don't
understand? I said MOST carbon rims. And where did you get
the reliability data on American made tubeless carbon rims?

What you are saying that if I'm willing to spend 5 times
as much I will get a reliable rim when the vast majority
of manufacturers don't seem to share your opinion and have
changed back to aluminum rims with carbon fairings.

I am curious as to why you would make patently false
claims for no other reason than to criticize a posting I
placed here to warn people off.

I'm curious why non-racers buy carbon rims in the first
place.



Because they want carbon rims probably. Who knows why
anyone wants anything? It's not always Veblen.

Not always...

But I don't consider the "why want that?" question to be
unanswerable. Certainly the justifications are sometimes
multiple and/or complicated, but that doesn't mean it should
all be labeled unknowable.

And I think it is worth remembering that lots of our
purchasing is heavily influenced by advertising and "me too"
culture. As someone recently noted, there was a time not
_that_ long ago when people didn't buy shampoo (they just
used soap)... let alone mouthwash, lip gloss, cowboy boots,
SUVs, neckties, fidget spinners, AR-15s, Fitbits.

Bicycling is far from immune from those forces.



Certainly products have different features!Â* My girlfriend's homestead
still has a completely worn out 1892 Winchester and the same basic
design, also seriously worn, from 1962 also chambered .30Win. Did those
reliably feed her ancestors down to her younger siblings? Yep. My AR15
in .223 is lighter, easier to strip/clean and every little piece of it
from the smallest spring to a new barrel is available from literally
hundreds of vendors at a range of price/quality. Nothing wrong with a
lever action .30Win, and the old irons are just beautiful on the wall,
but if you want something to actually use, AR15 beats it in every way.

And so to carbon rims.Â* Do I need a set? well, uh, no I don't. But that
doesn't mean someone else looking for lighter weight wouldn't find a
pair of Bora attractive. Having been in this business a very long while,
people make purchase decisions in complex ways that sometimes the buyer
herself doesn't fully understand or acknowledge.Â* There's also general
human progress, in that without oddball designers and screwy consumers
we would never have real innovation. That has value and a soviet style
planned economy suffers the lack of it.

You've done a good job of explaining why _you_ want an AR-15. But
consider some other examples I gave - mouthwash, lip gloss, cowboy
boots, SUVs, neckties, fidget spinners... I think most people's answers
would be far less logical.

Which is not to say that every purchase needs to be justified
technically, or even rationally. About a year ago I was playing music
for a gig at an art gallery and I blew my pay on a small wire sculpture
that I thought (correctly) my wife would love. And certainly the next
music CD I buy won't change my life in any tremendous way. There is room
for art and beauty.

But a lot of the "beauty" that people pay for is worse than ephemeral.
It's fashion that would probably not exist without advertising's power
to create demand.

This does happen in bicycling. I'm sure there are guys who, fifteen
years ago, were all agog at 16 spoke wheels and aero frame tubes; but
who are now buying into Jan Heine's fat tired randonneuring bikes with
wide aluminum fenders.

I won't tell them not to buy one. But I think it's wise to evaluate
one's goals and motives from time to time, and be sure one's not being
unduly manipulated.

And I think that's a good idea for many areas of interest, not just
shopping.


--
- Frank Krygowski

On Mon, 03 Dec 2018 12:01:11 -0600, AMuzi wrote:

On 12/3/2018 10:26 AM, wrote:
On Monday, December 3, 2018 at 6:12:54 AM UTC-8, wrote:
On Monday, December 3, 2018 at 1:23:55 AM UTC+1, jbeattie wrote:
On Sunday, December 2, 2018 at 3:09:21 PM UTC-8, John B. slocomb wrote:
giant snip

Apparently you are unfamiliar with this foreign concept - United States Postal Service. Exactly what you would have a dealer using after charging you as much as 10 times more than I paid. But I'm sure you're rolling in cash and that means nothing to you.

Goodness! We were talking about the alleged "fact" that you posted
that "Most carbon rims are made in China from prepreg from Japan" and
I pointed out that carbon rims are also made by U.S. companies and
that their warranty is for 5 years.

Now you are off on a on a trip through the intricacies of the USPS and
apparently complaining that U.S. made wheels are more costly then the
cheap Chinese wheels that you bought.

The last time I corrected your fantasies you changed the subject to
India and now it is (apparently) how impoverish you are.

Wake up Tom, buying stuff because it is cheap and having it fail is
not saving money.

With his history of CF disasters, TK should be buying the most reliable products on the market sold by domestic sellers with domestic insurers. Try recovering a personal injury settlement or judgment from a Chinese manufacturer who sells direct -- or its insurer in China. Justify the increased price as an insurance premium.

That is also what surprized me. How can a person with that history and the following rants about CF buy cheap Chinese CF stuff. Unbelievable. You can buy Pinnarello frame for 350 euro, looking exactly the same as the originals a probably used in the same moulds, but the measurements showed completely different values. With CF is all about lay ups, used preps and quality control. The fact that something is produced in the same country (China) doesn't mean anything. I stay far far far away from CF with an unknown pedigree as you call it. Tom should do the same IMO. CF rims for clinchers are difficult hence their price, CF rims for tubeless even more difficult and than buying cheap Chinese stuff? WTF is he thinking...




Assuming that the wheels TK bought were unbranded versions of reputable wheels made in a Chinese factory, that means that the factory was knocking them off and stealing its customer's IP -- not something we want to promote. Assuming that the customer is actually policing its IP and its factory, then the knock-off is probably coming from a different factory and is of unknown quality. Now, there have been some very good knock-offs. Phil Knight busted a factory for knocking off Nikes and then hired them because the knock-offs were so good. However, there is no way of knowing in advance what knock-offs are really good and which aren't -- and unlike shoes, you can't see the "stitching" and materials and workmanship of a CF rim. For all you know, there are giant voids and a ****ty lay-up. OTOH, it might be O.K. stuff, but if I had landed on my head a bunch of time because of broken CF bits, O.K. would not be good enough.

+1

Lou

Lou - Where did you see this bike made out of Pinarello molds that had completely different measurements? How did you measure it? My guess is that as usual it is an urban myth.

That reminds me of that video I referenced that showed a high capacity wheel factory in China and someone here referencing a wheel building plant here which had technology 40% of the Chinese version. Almost all of the carbon fiber frames are built in China, Taiwan or India. Do you think that Trek is built here? Have you looked at the C64 Colnago? Knowing what I know not I wouldn't touch that Italian made POJ.

Chinese engineering is as good as anywhere else. Hell, most of their engineers go through American universities. The only problem is when they cut corners to sell cheaper. They are not cutting any corners on the clincher wheels since they are the same wheels used by several British and French "manufacturers" who improve their product by adding a decal. For instance - MAVICs are built in China.

I was totally against CF after several failures I observed personally but after extensive research and actually talking to engineers working with CF at Boeing I changed my opinion. It ain't the material, but the use of the material. Like any other material it has design limitations and if you remain within those limits you're fine.

The tubeless wheels aren't inherently bad designs, they simply do not have the quality control for that specific use. Do you suppose they just released those things without testing them? If they were breaking all the time their test lot would have shown it. But the difference between a test lot and a production lot can be worlds apart.



"Chinese engineering is as good as anywhere else. Hell, most
of their engineers go through American universities."

I do not believe either of those are true.

Chinese collages turns out something like 800,000 engineers a year.
See http://www.besteduchina.com/engineer..._in_china.html

Given that the U.S. hosts about 1.1 million foreign students, see
https://www.migrationpolicy.org/arti...-united-states

It would mean that for U.S. educated Chinese engineering students make
up more then the 800,000 turned out in Chinese schools, nearly all of
the foreign students in U.S. collages must be Chinese engineering
students.

cheers,

John B.

On Mon, 3 Dec 2018 18:10:51 -0500, Frank Krygowski
wrote:

On 12/3/2018 1:52 PM, wrote:
On Monday, December 3, 2018 at 10:01:13 AM UTC-8, AMuzi wrote:
On 12/3/2018 10:26 AM, wrote:
On Monday, December 3, 2018 at 6:12:54 AM UTC-8, wrote:
On Monday, December 3, 2018 at 1:23:55 AM UTC+1, jbeattie wrote:
On Sunday, December 2, 2018 at 3:09:21 PM UTC-8, John B. slocomb wrote:
giant snip

Apparently you are unfamiliar with this foreign concept - United States Postal Service. Exactly what you would have a dealer using after charging you as much as 10 times more than I paid. But I'm sure you're rolling in cash and that means nothing to you.

Goodness! We were talking about the alleged "fact" that you posted
that "Most carbon rims are made in China from prepreg from Japan" and
I pointed out that carbon rims are also made by U.S. companies and
that their warranty is for 5 years.

Now you are off on a on a trip through the intricacies of the USPS and
apparently complaining that U.S. made wheels are more costly then the
cheap Chinese wheels that you bought.

The last time I corrected your fantasies you changed the subject to
India and now it is (apparently) how impoverish you are.

Wake up Tom, buying stuff because it is cheap and having it fail is
not saving money.

With his history of CF disasters, TK should be buying the most reliable products on the market sold by domestic sellers with domestic insurers. Try recovering a personal injury settlement or judgment from a Chinese manufacturer who sells direct -- or its insurer in China. Justify the increased price as an insurance premium.

That is also what surprized me. How can a person with that history and the following rants about CF buy cheap Chinese CF stuff. Unbelievable. You can buy Pinnarello frame for 350 euro, looking exactly the same as the originals a probably used in the same moulds, but the measurements showed completely different values. With CF is all about lay ups, used preps and quality control. The fact that something is produced in the same country (China) doesn't mean anything. I stay far far far away from CF with an unknown pedigree as you call it. Tom should do the same IMO. CF rims for clinchers are difficult hence their price, CF rims for tubeless even more difficult and than buying cheap Chinese stuff? WTF is he thinking...




Assuming that the wheels TK bought were unbranded versions of reputable wheels made in a Chinese factory, that means that the factory was knocking them off and stealing its customer's IP -- not something we want to promote. Assuming that the customer is actually policing its IP and its factory, then the knock-off is probably coming from a different factory and is of unknown quality. Now, there have been some very good knock-offs. Phil Knight busted a factory for knocking off Nikes and then hired them because the knock-offs were so good. However, there is no way of knowing in advance what knock-offs are really good and which aren't -- and unlike shoes, you can't see the "stitching" and materials and workmanship of a CF rim. For all you know, there are giant voids and a ****ty lay-up. OTOH, it might be O.K. stuff, but if I had landed on my head a bunch of time because of broken CF bits, O.K. would not be good enough.

+1

Lou

Lou - Where did you see this bike made out of Pinarello molds that had completely different measurements? How did you measure it? My guess is that as usual it is an urban myth.

That reminds me of that video I referenced that showed a high capacity wheel factory in China and someone here referencing a wheel building plant here which had technology 40% of the Chinese version. Almost all of the carbon fiber frames are built in China, Taiwan or India. Do you think that Trek is built here? Have you looked at the C64 Colnago? Knowing what I know not I wouldn't touch that Italian made POJ.

Chinese engineering is as good as anywhere else. Hell, most of their engineers go through American universities. The only problem is when they cut corners to sell cheaper. They are not cutting any corners on the clincher wheels since they are the same wheels used by several British and French "manufacturers" who improve their product by adding a decal. For instance - MAVICs are built in China.

I was totally against CF after several failures I observed personally but after extensive research and actually talking to engineers working with CF at Boeing I changed my opinion. It ain't the material, but the use of the material. Like any other material it has design limitations and if you remain within those limits you're fine.

The tubeless wheels aren't inherently bad designs, they simply do not have the quality control for that specific use. Do you suppose they just released those things without testing them? If they were breaking all the time their test lot would have shown it. But the difference between a test lot and a production lot can be worlds apart.



"Chinese engineering is as good as anywhere else. Hell, most
of their engineers go through American universities."

I do not believe either of those are true.

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

Andrew - do you have some big-time engineering universities around where you live? MIT? All you have to do is ask them.

Now we get a WHOLE lot of shoddy Chinese products but it almost entirely isn't from the engineering but from the marketing and management cutting corners.

My impression has been that Chinese companies are notorious for piracy,
copying, intellectual property violations, etc. I'm sure that China has
many super-competent engineers. I'm also sure they have many engineers
that are far less competent, and that they have companies that don't
employ any engineers. They just have workers who are halfway decent at
copying someone else's design and making it look good. I'm betting that
there are hundreds of such companies, mostly tiny, flooding markets with
products with surprisingly low prices.

If someone in any country wanted to copy a top quality aluminum alloy
rim, they could do it pretty easily. Extrusion dies are inexpensive and
extruding is a mature, well understood technology. Get yourself an
extrusion press, a furnace or billet heater, a decent die maker, and
you're in business. Bending and drilling are all that remain. The only
way to screw up is to use the wrong alloy (and perhaps heat treatment,
for some rims).

Carbon fiber is different. It's a much more finicky process, there can
be much more variation in the fiber, the resin and the layup. And
quality control is much more sophisticated than for extrusion.

I'm not in any way saying Chinese CF products are all bad. But I'll bet
heavily that a higher percentage of Chinese CF products are junk,
compared to American CF products.

Probably true, but a practice followed by just about every "developing
country" - sell cheap, corner the market and then improve the product.

Japan did exactly this after WW II. I can well remember the days when
"Made in Japan equated to "cheap junk". In fact I can remember my own
amazement the first time that someone used the term "made in Japan" to
indicate a quality product :-)

Thailand did the same thing. I can remember when a Thai assembled car
was a disaster waiting to happen. Now, the last three cars we've
bought were Thai assembled and no problems with any of them.

In fact in the period, slightly before WW II there was a popular song
in Japan "A celluloid doll from America" that described a doll made in
the U.S., so pretty but so easily broken.

cheers,

John B.

On Mon, 03 Dec 2018 17:27:52 -0600, AMuzi wrote:

On 12/3/2018 4:27 PM, Frank Krygowski wrote:
On 12/3/2018 12:54 PM, AMuzi wrote:
On 12/2/2018 9:25 PM, Frank Krygowski wrote:
On 12/2/2018 7:17 PM, wrote:
On Sunday, December 2, 2018 at 3:09:21 PM UTC-8, John B.
slocomb wrote:

Goodness! We were talking about the alleged "fact" that
you posted
that "Most carbon rims are made in China from prepreg
from Japan" and
I pointed out that carbon rims are also made by U.S.
companies and
that their warranty is for 5 years.

Now you are off on a on a trip through the intricacies of
the USPS and
apparently complaining that U.S. made wheels are more
costly then the
cheap Chinese wheels that you bought.

The last time I corrected your fantasies you changed the
subject to
India and now it is (apparently) how impoverish you are.

Wake up Tom, buying stuff because it is cheap and having
it fail is
not saving money.

John, is there something about "most" you don't
understand? I said MOST carbon rims. And where did you get
the reliability data on American made tubeless carbon rims?

What you are saying that if I'm willing to spend 5 times
as much I will get a reliable rim when the vast majority
of manufacturers don't seem to share your opinion and have
changed back to aluminum rims with carbon fairings.

I am curious as to why you would make patently false
claims for no other reason than to criticize a posting I
placed here to warn people off.

I'm curious why non-racers buy carbon rims in the first
place.



Because they want carbon rims probably. Who knows why
anyone wants anything? It's not always Veblen.

Not always...

But I don't consider the "why want that?" question to be
unanswerable. Certainly the justifications are sometimes
multiple and/or complicated, but that doesn't mean it should
all be labeled unknowable.

And I think it is worth remembering that lots of our
purchasing is heavily influenced by advertising and "me too"
culture. As someone recently noted, there was a time not
_that_ long ago when people didn't buy shampoo (they just
used soap)... let alone mouthwash, lip gloss, cowboy boots,
SUVs, neckties, fidget spinners, AR-15s, Fitbits.

Bicycling is far from immune from those forces.



Certainly products have different features! My girlfriend's
homestead still has a completely worn out 1892 Winchester
and the same basic design, also seriously worn, from 1962
also chambered .30Win. Did those reliably feed her ancestors
down to her younger siblings? Yep. My AR15 in .223 is
lighter, easier to strip/clean and every little piece of it
from the smallest spring to a new barrel is available from
literally hundreds of vendors at a range of price/quality.
Nothing wrong with a lever action .30Win, and the old irons
are just beautiful on the wall, but if you want something
to actually use, AR15 beats it in every way.

I'm not sure that I agree with all that :-) My grandfather had two
1892 Winchesters, one with a half length magazine and one with a full
length, both 38-55. He killed a deer every year, usually with one
shot, and often more then one if the game warden wasn't around.
My father used a Savage Model 99 and again mostly 1 shot kills.

Can you get more efficient than that.

And so to carbon rims. Do I need a set? well, uh, no I
don't. But that doesn't mean someone else looking for
lighter weight wouldn't find a pair of Bora attractive.
Having been in this business a very long while, people make
purchase decisions in complex ways that sometimes the buyer
herself doesn't fully understand or acknowledge. There's
also general human progress, in that without oddball
designers and screwy consumers we would never have real
innovation. That has value and a soviet style planned
economy suffers the lack of it.

cheers,

John B.

On Thursday, November 29, 2018 at 6:05:02 PM UTC-5, wrote:
I previously bought a set of 50 mm deep Carbon Fiber rims. These were clinchers and were 23 mm wide on the brake surfaces. These have performed faultlessly.

But I didn't want to have to carry around all of the 2 lbs of flat repair stuff - the Topeak bag, multitool, two spare tubes, two CO2 cartridges and the tool to use them and a patch kit ifneeded.

So I decided to go to tubeless as I have successfully used on Campy and Fulcrum aluminum wheelsets. They were selling the 25 mm wide tubeless wheelsets nearly as cheaply as the clincher rims.

I bought a set and they arrived. I also wanted to try 28 mm tires on my Colnago so I was mounting a set of Michelin Pro4 Endurance tires like I had used on my Pinarello Stelvio. The front appeared to mount and hold air as normal for a new mount. Usually it takes a couple of days for all of the small leaks around the sidewalls to seal. You just pump it up until it hold air pretty well and then go for a ride and that jiggles everything into place and you don't have to worry about flats again.

When I was inflating the rear tire and inflating it, there was a loud POP! and I put the wheel into the wheelstand and it was an inch out of true. I assumed this was from delamination but as the wheel was spinning in the stand the air was draining out of it and it came back into true. I pulled the tire off and looked carefully at the entire rim but couldn't see anything. I contacted the seller on Ebay and they sent me a rim which I've covered elsewhere.

In any case I ordered a second wheelset from another manufacturer. They came in pretty fast so they must have gotten to the boat just as it was leaving.

I discovered with the apparently good front wheel that there's insufficient room on the CLX 3.0 to use 28 mm tires. Conveniently Vittoria just released the Corsa Speed tubeless tires so I ordered a set from ProBikeKit. It took a month to get here so it was just a couple of days ago I tried putting them on. I had a lot of problems getting them to push up onto the step that all tubeless rims have. In fact I used up 5 CO2 cartridges without getting one properly mounted. So I had to order another lifetime supply. I expected them to arrive in another week but they were here this morning!

I mounted the new tires and inflated them and they didn't fill properly still. They were spraying the sealant all over the place. Finally they seemed to mount properly. The air pressure was low from all of the leakage getting them on properly. so I stuck a pump on and started pumping them up at around 65 psi they started TICing and when I got to 80 PSI they exploded loudly and the way the tire felt I thought that it had broken the bead. I tried the other wheel and it did the same thing. When the pressure got to 70 psi or so it began making funny noises and at 80 psi BANG!

I called Vittoria America up and gave them a piece of my mind and they were the nicest people in the world and just gave me a return ID and said that they would replace them.

So I went through the process of taking them off with all of that sealant inside. I got them off and there didn't seem to be anything wrong with the tires. So I rubbed by fingers along the top of the rims and one was delaminated for about 10 inches while the other was delaminated a third of the way around the one side of the rim. I kept the wheel box but I cannot return them through Ebay until I communicate with the seller.

Now the tube bed on the clincher wheels is completely different than that of the tubeless so I don't expect any trouble with them. But what is important to note is that probably all 50 mm deep carbon rims are made by the same manufacturer. This makes them all suspect no matter whose decal is on the rims.

If you want the advantages of a good aero section that you can get from carbon 50 mm wheels you should think more about a clincher set. These have more re-enforcement around the brake area.

Buying ANYTHING CARBON from a unknown Chinese builder is a crap shoot at best and possible life threatening at worst. I can't believe the number of people who risk their limbs and health on cheap often shoddily built Chinese knockoffs/pirated copies of bicycles or bicycle components. The adage, "If the price looks to be too low to be good" then it probably is.

Cheers