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Danger from CF rims



 
 
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  #41  
Old December 3rd 18, 05:04 PM posted to rec.bicycles.tech
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Posts: 1,261
Default Danger from CF rims

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.
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  #42  
Old December 3rd 18, 05:26 PM posted to rec.bicycles.tech
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Posts: 1,261
Default Danger from CF rims

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.
  #43  
Old December 3rd 18, 06:54 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default Danger from CF rims

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.

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


  #44  
Old December 3rd 18, 06:55 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default Danger from CF rims

On 12/3/2018 4:58 AM, John B. slocomb wrote:
On Sun, 02 Dec 2018 18:09:42 -0600, AMuzi wrote:

On 12/2/2018 5:09 PM, John B. slocomb wrote:
On Sun, 2 Dec 2018 09:28:53 -0800 (PST), wrote:

On Saturday, December 1, 2018 at 3:24:08 PM UTC-8, John B. slocomb wrote:
On Sat, 1 Dec 2018 15:05:53 -0800 (PST),
wrote:

On Friday, November 30, 2018 at 3:23:36 PM UTC-8, John B. slocomb wrote:
On Fri, 30 Nov 2018 07:22:40 -0800 (PST),
wrote:

On Friday, November 30, 2018 at 5:41:36 AM UTC-8, AMuzi wrote:
On 11/29/2018 7:23 PM, jbeattie wrote:
On Thursday, November 29, 2018 at 3:05:02 PM UTC-8, 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.

WTF? You and cheap carbon wheels should not be on the same planet together. Go get some decent aluminum rims and call it good -- or some CF/aluminum hybrids like the DuraAce. They're a good value and getting cheaper because of the shift to disc wheels. You can skip the special brake pads and sketchy wet-weather braking -- or in your case, hot weather braking on long descents. For most people, CF rims are a solution in search of a problem.

-- Jay Beattie.


I linked earlier to Campagnolo wheels but Tom seems hellbent
on incrementally financing the People's Navy which is
building supercarriers.

Andrew, as I explained to you before - Mavic, Fulcrum and Campy wheel components are almost entirely made in China or Taiwan. They send the components to Romania or Italy or France for assembly which allows these companies to claim place of origin.

Most carbon rims are made in China from prepreg from Japan.

https://www.youtube.com/watch?v=2XqJ9eZUG58

Zipp wheels are made in China by SRAM.

Probikekit which usually has the cheapest wheel prices around are quoting almost $2,000 for a 50 mm deep Shimano wheelset and they ONLY have Shimano freehubs. Do you have some other source?

It appears that all of these companies have been having trouble with delamination and that is why they are changing over to aluminum hubs with carbon fiber fairings on them. Most of these are between 200 and 400 grams heavier per set.

So as I said, it this is a warning that these tubeless rims do not work and they in all likelihood do not work for any manufacturer.

Or we can pretend like Jay that if they are "made in America" they would work fine.

Gee Tom, yet another example of your fantasies.

ENVE, located in Ogden, Utah, makes carbon fiber wheels and guarantees
them for 5 years:

"We warrant all products to be free from defects in materials or
workmanship for five years from the original purchase date (valid
proof of purchase required)."

And, have 50 dealers in and around San Francisco (50 mile radius).


cheers,

John B.

John, ask Jay what a warranty is worth. The wheels I bought have a two year warranty on them.

Yes, of course. Just carry them back to China and they will likely
replace them. What is a round trip to, oh say, Shanghai, cost these
days. In contract there are, as I told you, some 50 dealers in driving
distance to San Francisco.

As for Jay, he has mentioned a number of times breaking a bike and
having it replaced under warranty.


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.


Well, there's that.

Regarding your exhortation 'wake up', the People's
Liberation Army Navy* has four keels down for supercarriers,
financed by XMart shoppers.

*I didn't make that up. It's the real name of The Party's
Navy (which is not the nation's navy).


True. The Mainlanders seem to have an "Army" which encompasses all of
their military. the Army, The Army Navy, The Army Airforce...

Rather like the U.S. with their "Defense Department" when the last
defensive war was fought 200 years ago, or there about, which they
lost, so to speak. Why not the "War Department"?


+1
The War Department was self explanatory and apt.


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


  #45  
Old December 3rd 18, 07:01 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default Danger from CF rims

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


  #46  
Old December 3rd 18, 07:39 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 824
Default Danger from CF rims

On Monday, December 3, 2018 at 5:26:06 PM UTC+1, 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:



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.


It was in TOUR magazin the most respectable and leading bike magazine here in Europe. They measured it by their standards by which every bike frame is tested. I truly believe they are the only independent bike magazine I know. When it is crap they tell it is crap. They critized/opposed to Shimano road disk brakes for heavy riders and still have reservations. The difference between the real Pinarello and the fake was astonishing. Both made in China.
The Chinese are very capable and hardworking people but like anywhere else you get what you pay for. I know enough examples in my lie of work. If you pay crap prices you get eventually (not in the beginning) crap products or someone is exploited or both. Even the Chinese have to make a living. You have to keep that always in mind.

Lou
  #47  
Old December 3rd 18, 07:52 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,261
Default Danger from CF rims

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.
  #48  
Old December 3rd 18, 07:54 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,261
Default Danger from CF rims

On Monday, December 3, 2018 at 10:39:07 AM UTC-8, wrote:
On Monday, December 3, 2018 at 5:26:06 PM UTC+1, 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:



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.


It was in TOUR magazin the most respectable and leading bike magazine here in Europe. They measured it by their standards by which every bike frame is tested. I truly believe they are the only independent bike magazine I know. When it is crap they tell it is crap. They critized/opposed to Shimano road disk brakes for heavy riders and still have reservations. The difference between the real Pinarello and the fake was astonishing. Both made in China.
The Chinese are very capable and hardworking people but like anywhere else you get what you pay for. I know enough examples in my lie of work. If you pay crap prices you get eventually (not in the beginning) crap products or someone is exploited or both. Even the Chinese have to make a living. You have to keep that always in mind.

Lou


Well, I suppose you can believe what you like. I would have to read that article to even pass any opinion on it.
  #49  
Old December 3rd 18, 09:54 PM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 5,870
Default Danger from CF rims

On Monday, December 3, 2018 at 10:54:19 AM UTC-8, wrote:
On Monday, December 3, 2018 at 10:39:07 AM UTC-8, wrote:
On Monday, December 3, 2018 at 5:26:06 PM UTC+1, 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:



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.


It was in TOUR magazin the most respectable and leading bike magazine here in Europe. They measured it by their standards by which every bike frame is tested. I truly believe they are the only independent bike magazine I know. When it is crap they tell it is crap. They critized/opposed to Shimano road disk brakes for heavy riders and still have reservations. The difference between the real Pinarello and the fake was astonishing. Both made in China.
The Chinese are very capable and hardworking people but like anywhere else you get what you pay for. I know enough examples in my lie of work. If you pay crap prices you get eventually (not in the beginning) crap products or someone is exploited or both. Even the Chinese have to make a living. You have to keep that always in mind.

Lou


Well, I suppose you can believe what you like. I would have to read that article to even pass any opinion on it.


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. 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.


-- Jay Beattie.
  #50  
Old December 3rd 18, 11:27 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Danger from CF rims

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.


--
- Frank Krygowski
 




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