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Discussion Starter · #1 ·
This one of the best video talking about carbon fiber frame construction to a layman I've seen. My take away message after watching this is that while carbon fiber is a great material to build bicycles, but getting it right is not a trivial job. Another thing that carbon fiber can fatigue and fail due to wrinklings, as Raoul explained about the heat tube and bottom bracket areas in the video.

 

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I enjoyed the video. I learned a lot about carbon frames. I never wanted one myself and this video did not change that for sure.
 

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And totally not self-serving or biased at all. It isn't like his business depends on convincing people carbon is dangerous and there could be unseen problems. Better bring your frames and wheels to him for an ultrasound.

Wait
 

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And totally not self-serving or biased at all. It isn't like his business depends on convincing people carbon is dangerous and there could be unseen problems. Better bring your frames and wheels to him for an ultrasound.

Wait
Well around here people take their Carbon frames to Calfee for repair or whatever it is they want done. I'm sure they have the tech to tell you if you have a frame with wrinkles.
 

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I've watched quite a few of his videos. I'm not terribly offended by them, but not terribly impressed either. He really doesn't say much. It's mostly just noise. He seems to be being very careful not to offend the bike manufacturers, and never really makes any specific claims.

It does get a little uncomfortable when he makes statements like "10 year old carbon frames all of problems with cracking bottom brackets". This certainly isn't true. Yes, manufacturing, engineering, design have all come a long way, and surely carbon frames are better in just about every possible way than they were 10 years ago, but those older bikes don't all have problems with cracks around the bottom bracket.
 

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Discussion Starter · #7 ·
And totally not self-serving or biased at all. It isn't like his business depends on convincing people carbon is dangerous and there could be unseen problems. Better bring your frames and wheels to him for an ultrasound.

Wait
you might wanna go see a few of his other videos about him. He is veteran from the aerospace industry and has consulted for some major aerospace space companies and I think Australian cycling team. He is a major proponent for using carbon fiber for bicycles... PROVIDED that it is done correctly.

He's about to come to Socal to University of California Irvine to give a presentation of material science to the likes of aerospace industry engineers from Boeing, grad students, etc.

I don't think his livelihood depends on scaring cyclists to bring carbon frames to him for a check.

Technically, I find what he said to be interesting. There are lots of folks who still "carbon fiber doesn't fatigue", but here we have an expert who explains that carbon fiber can fatigue if not done right
 

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Discussion Starter · #8 ·
I've watched quite a few of his videos. I'm not terribly offended by them, but not terribly impressed either. He really doesn't say much. It's mostly just noise. He seems to be being very careful not to offend the bike manufacturers, and never really makes any specific claims.

It does get a little uncomfortable when he makes statements like "10 year old carbon frames all of problems with cracking bottom brackets". This certainly isn't true. Yes, manufacturing, engineering, design have all come a long way, and surely carbon frames are better in just about every possible way than they were 10 years ago, but those older bikes don't all have problems with cracks around the bottom bracket.
A lot of his videos are made by another person who stops by his shop and asks him questions on the spot and he talks, sort of like water cooler talk. They aren't dissertations. How many youtube videos out there where a guy cuts up a bunch of carbon frames and forks and wheels like he does and explain to the layman the inner construction of a carbon frame and their point of possible failures? I don't know many videos. If you have some videos that you're impressed with, please share with us. Note, I'm not looking to read a grad level academic text or reference on carbon fiber to impress me, ok.
 

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I've watched quite a few of his videos. I'm not terribly offended by them, but not terribly impressed either. He really doesn't say much. It's mostly just noise. He seems to be being very careful not to offend the bike manufacturers, and never really makes any specific claims.

It does get a little uncomfortable when he makes statements like "10 year old carbon frames all of problems with cracking bottom brackets". This certainly isn't true. Yes, manufacturing, engineering, design have all come a long way, and surely carbon frames are better in just about every possible way than they were 10 years ago, but those older bikes don't all have problems with cracks around the bottom bracket.
-this- I have watched most of his videos and the vast majority of them seem to be produced by that "CyclingMaven" guy. While interesting and informative from a "get the layup right" point of view, the bulk of most of them is talking in very vague terms, and trying to draw comparisons between bike frames and airplanes. Sprinkled with pretty lengthy sessions of talking about nothing.
 

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Discussion Starter · #11 ·
-this- I have watched most of his videos and the vast majority of them seem to be produced by that "CyclingMaven" guy. While interesting and informative from a "get the layup right" point of view, the bulk of most of them is talking in very vague terms, and trying to draw comparisons between bike frames and airplanes. Sprinkled with pretty lengthy sessions of talking about nothing.
You probably were referring to this video below, at around 6 minute mark, he talks about how the differences between the carbon fiber used in aerospace, specifically in Boeing, versus the run of the mill carbon fiber used in cycling industry. In the same breath, he also talked about bubbling and marbling and how that would be considered a defect because it indicates wrinkling underneath and wouldn't be acceptable in aerospace. I thought this was very informative. Right here on RBR, there were a few threads from people over the years complaining about Cervelo's and other brand's bubbling/marbling issues on the down tubes or seat tubes or top tubes. And many folks would chime in and say, oh it's just a "cosmetic", just clear coat bubbling, but that the integrity of the carbon is OK. But according to this guy, they could/would indicate a defect in manufacturing and probably not acceptable to him.

He also went on to talk about the forks from Giant and Specialized but I'll let the readers watch it.

I found most of his talk quite informative and certainly the information is quite applicable to a person who is looking to perhaps buy a used carbon frame or a chinese ebay carbon frame (where QA control is probably nonexistance). At least now they know what to look for after watching his videos. I don't get a sense that he's being an alarmist, just methodical and informative.

But maybe you're an expert in carbon fiber so you don't find his info much use.

 

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You probably were referring to this video below, at around 6 minute mark, he talks about how the differences between the carbon fiber used in aerospace, specifically in Boeing, versus the run of the mill carbon fiber used in cycling industry. In the same breath, he also talked about bubbling and marbling and how that would be considered a defect because it indicates wrinkling underneath and wouldn't be acceptable in aerospace. I thought this was very informative. Right here on RBR, there were a few threads from people over the years complaining about Cervelo's and other brand's bubbling/marbling issues on the down tubes or seat tubes or top tubes. And many folks would chime in and say, oh it's just a "cosmetic", just clear coat bubbling, but that the integrity of the carbon is OK. But according to this guy, they could/would indicate a defect in manufacturing and probably not acceptable to him.

He also went on to talk about the forks from Giant and Specialized but I'll let the readers watch it.

I found most of his talk quite informative and certainly the information is quite applicable to a person who is looking to perhaps buy a used carbon frame or a chinese ebay carbon frame (where QA control is probably nonexistance). At least now they know what to look for after watching his videos. I don't get a sense that he's being an alarmist, just methodical and informative.

But maybe you're an expert in carbon fiber so you don't find his info much use.

Yeah man, I agree with most of what you say, particularly in regards to chinese carbon, where it could be helpful to folks who insist they are getting a high quality product when they may not be. I just find the videos have too much filler for my taste. Admit to not watching the one you posted in your OP yet. I will check it out and report back. I'm no expert in carbon to be sure. I have seen a great deal of carbon frames from most manufacturers and believe I know what a good layup and finishing job looks like compared to a lesser quality one. I ride carbon. But I am not anywhere close to being an expert.
 

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I watched both video's and enjoyed them. I have never ridden on a carbon bike (or ti, aluminum) myself and I do not see an opportunity but now I know a couple things about manufacture of carbon and such. It's pretty interesting. I guess I wish that he would have cut up a Motobecane carbon as some of my friends ride them and I am curious as to how the budget carbon bikes hold up to his inspections.
 

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How old is this Video? It strikes me that his was applicable about 20 years ago.
This one of the best video talking about carbon fiber frame construction to a layman I've seen. My take away message after watching this is that while carbon fiber is a great material to build bicycles, but getting it right is not a trivial job. Another thing that carbon fiber can fatigue and fail due to wrinklings, as Raoul explained about the heat tube and bottom bracket areas in the video.

 

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Ok I watched it and admit that this particular video is far better than his others. He actually shows branded frames, and gets into far more detail than before. His explanations make sense and confirms what has been the bike shop belief regarding carbon frames. The smoother the interior surface is, the better the compaction and general quality.
 

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The take away I get is that the big thing is process control. Now some things might be inspected visually when they come out of the mold, but for many things you need better NDT. We really don't have any way of knowing how much effort the Chinese put into process control, but certainly not like the Japanese have. It seems clear the "branded" bikes aren't getting much if any NDT. Testing some to failure may validate the design, but as he points out in the video, doesn't answer the process issues.

scott s.
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Real world conditions are likely the best NDT available as it impacts liability and sales. Until we see either catastrophic or age/fatigue related failures and associated litigation, we are fantasizing about what might be. Until then, maybe we should start awakening to what is.

I don't ride with anybody who has had a carbon frame failure that was defect related.
The take away I get is that the big thing is process control. Now some things might be inspected visually when they come out of the mold, but for many things you need better NDT. We really don't have any way of knowing how much effort the Chinese put into process control, but certainly not like the Japanese have. It seems clear the "branded" bikes aren't getting much if any NDT. Testing some to failure may validate the design, but as he points out in the video, doesn't answer the process issues.

scott s.
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You've never ridden anything but steel?
I have owned 3 road bikes in the last 4 decades. All steel. My current bike (4 yrs old) is a custom shop Columbus steel bike. I think that carbon bikes are nice and all but just have never ridden one. I would feel guilty going into a shop for a test ride when I am not actually serious about buying something. I did have a beat up old school aluminum mountain bike that I rode 1 mile to work.
 
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