Are CF frames really safe?

On Friday, May 19, 2017 at 4:51:44 PM UTC-7, jbeattie wrote:

There are hundreds of thousands of CF forks in the market (maybe millions). There is no epidemic of failure. I've been riding on CF forks since 1990, and unlike TK, I haven't broken any. YMMV. I am not as confident of CF steerers, but so far, my forks with CF steerers have not failed.

Let me get this straight - you think that wearing a helmet could help you in a crash but you don't think that a long history of carbon forks is enough for you to chose another path?


Most large manufacturers are insured under policies with self-insured retentions of varying sizes, some large. Really large manufacturers may have "fronting" policies (really a form of self-insurance) or an off-shore insurance program where they are the insurance company. "Really large" means companies like Ford.


Manufacturers like Trek and Specialized do rigorous QC. If in doubt, buy from a reputable company with a lifetime warranty and a US presence. I would steer clear of Colnago in light of TK's experience. Buy from a shop and not online.

The results of Trek's quality control is that they have built their frames and forks a great deal stronger. And they continue to break. Shortly after a friend got a new frame and fork from Trek after his Gary Fisher broke, I looked at the joint between the down tube and the seat tube. There was a visible split there. Trek replaced it yet again. Now this particular failure was unlikely to grow dangerous but it WAS a frame failure.

The results of Specialize's QC is that they have bought more and more insurance coverage and made lighter and lighter bikes because that's what the market wants.

https://www.youtube.com/watch?v=nvk63bmVpck

http://www.bustedcarbon.com/

This stuff is all over the web.

On Friday, May 19, 2017 at 7:05:17 PM UTC-7, John B. wrote:
On Fri, 19 May 2017 12:56:32 -0700 (PDT),
wrote:

With the price of a complete CF bicycle now approaching $1,000, one is tempted to buy one; however, I keep hearing stories about forks collapsing unexpectedly and without apparent reason.

Political commentator and devoted cyclist Victor Davis Hanson had such an accident some time back:

http://victorhanson.com/wordpress/th...giving-moment/

So I was wondering what you guys and gals think about this issue. Thanks for your opinions.

A coupe of years ago I was talking to a chap I know in Singapore who
specializes in taking your old beat up bike and turning it into what
appears to be a brand new unridden bicycle. In the conversation he
mentioned that he also repairs CF bikes and we got into a conversation
about that. I asked him what make of CF bike commonly broke and he
said, "the cheap Chinese ones". At the time of the conversation he
stated that he averaged about one CF bike repair a week.
The population of Singapore was about 4.5 million at the time.

Having said that I rode a Giant OCR2 with a C.F. fork for two years
with no problems at all.
--
Cheers,

John B.

John, I have been impressed with the mechanical design of the Giant CF bikes.

I'm not anti-carbon fiber - just that most of them are built to ultra-light specifications and you simply cannot make a safe bike out of paper thin anything.

On Friday, May 19, 2017 at 7:11:02 PM UTC-7, Sir Ridesalot wrote:
On Friday, May 19, 2017 at 10:05:17 PM UTC-4, John B. wrote:
On Fri, 19 May 2017 12:56:32 -0700 (PDT),
wrote:

With the price of a complete CF bicycle now approaching $1,000, one is tempted to buy one; however, I keep hearing stories about forks collapsing unexpectedly and without apparent reason.

Political commentator and devoted cyclist Victor Davis Hanson had such an accident some time back:

http://victorhanson.com/wordpress/th...giving-moment/

So I was wondering what you guys and gals think about this issue. Thanks for your opinions.

A coupe of years ago I was talking to a chap I know in Singapore who
specializes in taking your old beat up bike and turning it into what
appears to be a brand new unridden bicycle. In the conversation he
mentioned that he also repairs CF bikes and we got into a conversation
about that. I asked him what make of CF bike commonly broke and he
said, "the cheap Chinese ones". At the time of the conversation he
stated that he averaged about one CF bike repair a week.
The population of Singapore was about 4.5 million at the time.

Having said that I rode a Giant OCR2 with a C.F. fork for two years
with no problems at all.
--
Cheers,

John B.

My understanding of carbon fibre bicycles is that on the better quality ones the cloth is laid out in such a way as to give maxinum strength to the frame. Also, the resin used is confirmed to completely impregnate the carbon fiber cloth. On cheap carbon fiber bicycles the cloth is NOT laid out in the most optinum way to ensure that the frame is as strong as possible. Also, one the cheaper carbon fiber bicycles the cloth and/or the resin used may not be as good nor as carefully mixed and applied as it is on a better quality carbon fiber bicycle.

The layouts on ALL carbon fiber bikes is limited by the bi-directional characteristics of woven cloth. That means you cannot lay it out so that it gives maximum strength with minimal material.

On Friday, May 19, 2017 at 7:27:01 PM UTC-7, John B. wrote:
On Fri, 19 May 2017 22:08:17 +0200, Emanuel Berg
wrote:

With the price of a complete CF bicycle now
approaching $1,000, one is tempted to buy
one; however, I keep hearing stories about
forks collapsing unexpectedly and without
apparent reason.

I've also heard these stories. When I was in
the shop the other day there was a discussion
about buying a frame from Asia and putting your
own sticker on it, so you had your own bicycle
brand (sort of). Some guy who did bikes from
the 80s said that's unsafe because they can
disintegrate, I actually think it was the fork
in this story as well. Some other guy said
"aren't the pro frames from Asia as well?" The
80s guy said, "yes, but they are tested in
Europe". No idea what is true in all of this.

Probably most bike frames come from Asia these days, but likely the
big names do ensure that the bikes are made to a standard. For
example, while I have no idea where Columbus C.F. frames and forks are
actually made, their catalog contains a statement, "All of the
products of Columbus Carbon Lab. are tested to, and exceed, the
requirements of European Standard CEN14781", and I would assume that
all European bike sellers adhere to similar standards.
--
Cheers,

John B.

This is a strength standard and not a reliability standard.

On Saturday, May 20, 2017 at 12:46:41 PM UTC-7, wrote:
On Friday, May 19, 2017 at 4:51:44 PM UTC-7, jbeattie wrote:

There are hundreds of thousands of CF forks in the market (maybe millions). There is no epidemic of failure. I've been riding on CF forks since 1990, and unlike TK, I haven't broken any. YMMV. I am not as confident of CF steerers, but so far, my forks with CF steerers have not failed.

Let me get this straight - you think that wearing a helmet could help you in a crash but you don't think that a long history of carbon forks is enough for you to chose another path?


Most large manufacturers are insured under policies with self-insured retentions of varying sizes, some large. Really large manufacturers may have "fronting" policies (really a form of self-insurance) or an off-shore insurance program where they are the insurance company. "Really large" means companies like Ford.


Manufacturers like Trek and Specialized do rigorous QC. If in doubt, buy from a reputable company with a lifetime warranty and a US presence. I would steer clear of Colnago in light of TK's experience. Buy from a shop and not online.

The results of Trek's quality control is that they have built their frames and forks a great deal stronger. And they continue to break. Shortly after a friend got a new frame and fork from Trek after his Gary Fisher broke, I looked at the joint between the down tube and the seat tube. There was a visible split there. Trek replaced it yet again. Now this particular failure was unlikely to grow dangerous but it WAS a frame failure.

The results of Specialize's QC is that they have bought more and more insurance coverage and made lighter and lighter bikes because that's what the market wants.


https://www.youtube.com/watch?v=nvk63bmVpck

http://www.bustedcarbon.com/

This stuff is all over the web.

The number of failures is a tiny fraction of the total production, and there is usually poor documentation of failure mode in most of the doom and gloom reports. I'm not saying that CF never fails or breaks. Everything breaks. I've broken four steel frames and just as many aluminum. CF clearly is less impact resistant than steel, although modern resins are making current production more impact resistant. If you drop wrenches on your bikes, you should buy steel.

Specialized Tarmac and Roubaix in the non-S-Works models are actually a little heavier than industry average at the same price point. Specialized does a lot of QC and product testing, and I don't know what you're talking about with the "more and more insurance" bit. IMO, it's always been a reputable company, like Trek -- although both have been faulted for aggressive protection of IP/Trademark. That's a whole other thing.

I ride with guys who are both high mileage current or former racers and engineers or management for outdoor equipment companies. They all ride CF, and they don't change frames every year. My best riding buddy is on a ten year old Pinarello that he loves. The only person I know who had problems was a friend of my son who rode a (you guessed it) Colnago -- that took him 8 months to get warranty replaced. It failed while still in its two (?) year warranty. Again, not saying they're problem free, but its not like riding a ticking time bomb.

-- Jay Beattie.

On 5/21/2017 10:44 AM, jbeattie wrote:
On Saturday, May 20, 2017 at 12:46:41 PM UTC-7, wrote:
On Friday, May 19, 2017 at 4:51:44 PM UTC-7, jbeattie wrote:

There are hundreds of thousands of CF forks in the market (maybe millions). There is no epidemic of failure. I've been riding on CF forks since 1990, and unlike TK, I haven't broken any. YMMV. I am not as confident of CF steerers, but so far, my forks with CF steerers have not failed.

Let me get this straight - you think that wearing a helmet could help you in a crash but you don't think that a long history of carbon forks is enough for you to chose another path?


Most large manufacturers are insured under policies with self-insured retentions of varying sizes, some large. Really large manufacturers may have "fronting" policies (really a form of self-insurance) or an off-shore insurance program where they are the insurance company. "Really large" means companies like Ford.


Manufacturers like Trek and Specialized do rigorous QC. If in doubt, buy from a reputable company with a lifetime warranty and a US presence. I would steer clear of Colnago in light of TK's experience. Buy from a shop and not online.

The results of Trek's quality control is that they have built their frames and forks a great deal stronger. And they continue to break. Shortly after a friend got a new frame and fork from Trek after his Gary Fisher broke, I looked at the joint between the down tube and the seat tube. There was a visible split there. Trek replaced it yet again. Now this particular failure was unlikely to grow dangerous but it WAS a frame failure.

The results of Specialize's QC is that they have bought more and more insurance coverage and made lighter and lighter bikes because that's what the market wants.


https://www.youtube.com/watch?v=nvk63bmVpck

http://www.bustedcarbon.com/

This stuff is all over the web.

The number of failures is a tiny fraction of the total production, and there is usually poor documentation of failure mode in most of the doom and gloom reports. I'm not saying that CF never fails or breaks. Everything breaks. I've broken four steel frames and just as many aluminum. CF clearly is less impact resistant than steel, although modern resins are making current production more impact resistant. If you drop wrenches on your bikes, you should buy steel.

Specialized Tarmac and Roubaix in the non-S-Works models are actually a little heavier than industry average at the same price point. Specialized does a lot of QC and product testing, and I don't know what you're talking about with the "more and more insurance" bit. IMO, it's always been a reputable company, like Trek -- although both have been faulted for aggressive protection of IP/Trademark. That's a whole other thing.

I ride with guys who are both high mileage current or former racers and engineers or management for outdoor equipment companies. They all ride CF, and they don't change frames every year. My best riding buddy is on a ten year old Pinarello that he loves. The only person I know who had problems was a friend of my son who rode a (you guessed it) Colnago -- that took him 8 months to get warranty replaced. It failed while still in its two (?) year warranty. Again, not saying they're problem free, but its not like riding a ticking time bomb.

-- Jay Beattie.


That's a punk thing:
http://www.bikehugger.com/images/blog/bike_bomb.jpg

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

On Fri, 19 May 2017 12:56:32 -0700 (PDT),
wrote:

So I was wondering what you guys and gals think about this issue.

No opinions on CF safety but a few comments that might be of interest.

It is very easy to demonstrate that something is unsafe. All one
needs is an anecdotal failure incident, and it becomes unsafe. The
real question is what failure rate are you willing to tolerate? Along
that line, what lifetime are you expecting and what tolerance to
overload are you anticipating?

In other industries, where a catastrophic failure is unacceptable, the
standard practice is regular inspection and testing. In a past life,
I did some acoustic vibration analysis to predict conveyer belt
bearing failures. Lots of other tests for structural damage, cracks,
stresses, and corrosion, etc. Basically, one looks for something that
doesn't belong or has changed.

I don't see any of that in bicycling. I found a service that offers
bicycle CF "active thermography" inspection service in Germany:
http://carbon-bike-check.com (German)
http://www.infratec-infrared.com/thermography/application-area/active-thermography.html
Basically, they vibrate the frame with ultrasonic energy. Areas where
there are cracks become warmer, which can then be seen on an IR
camera.
http://carbon-bike-check.com/Motivation_1.jpg

This lack of testing really bugs me. Most CF owners do a visual
inspection and look for wrinkles in the paint or cracks. A few might
borrow some industrial inspection equipment:
http://www.olympus-ims.com
or shove a borescope/endoscope down the tube looking for potential
problems. I have a few of these:
http://www.ebay.com/itm/351973054942
The problem is that they only focus between approximately 2.5cm to
10cm. Good enough for automotive work, but not for pipe inspection.
I'm working on finding one with an adjustable focus and better depth
of field. Anyway, there are plenty of tools and toys to help with
inspection, but nobody that I know actually does it on a regular
schedule.

So, if you're going to buy into the CF club, and operate on the bitter
edge of mechanical failure to save a few grams, perhaps it might be
useful to find some inspection equipment and use it. It's much like
backing up a computah hard disk drive. Nobody expects it to fail, but
when it does, it can be catastrophic, happen without warning, and be
very expensive.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 5/21/2017 1:00 PM, Jeff Liebermann wrote:

No opinions on CF safety but a few comments that might be of interest.

It is very easy to demonstrate that something is unsafe. All one
needs is an anecdotal failure incident, and it becomes unsafe. The
real question is what failure rate are you willing to tolerate?

True. although in some cases you don't need an actual failure rate. If
you can imagine a failure, that sometimes suffices to label something
unsafe.

I'm on the Board of Commissioners managing a natural area owned by our
village. Some members of village council are worried about liability
from dead trees falling on people, even though the state supreme court
positively said there is no such liability regarding recreational users.

Regarding failure rate: I found a research paper that indicates the
entire U.S. has only about 12 such fatalities per year, not counting
those where a motorist runs into a fallen tree (which is impossible in
our forest). A biology professor attacked the issue from a different
direction and computed that the odds against a trail walker being hit by
a tree is up in the billions. And it goes without saying that there's
never been such an incident in the 80 year history of this forest.

But the councilman who is the big "danger!" guy heard of one incident
elsewhere in which a man sitting at a picnic table was hit by a falling
branch. So he (and the solicitor hired by the village) is commanding
that we survey all dead trees in the forest and classify them by a
"danger" ranking, then begin cutting them.


--
- Frank Krygowski

Jeff Liebermann wrote:
On Fri, 19 May 2017 12:56:32 -0700 (PDT),
wrote:

So I was wondering what you guys and gals think about this issue.

No opinions on CF safety but a few comments that might be of interest.

It is very easy to demonstrate that something is unsafe. All one
needs is an anecdotal failure incident, and it becomes unsafe. The
real question is what failure rate are you willing to tolerate? Along
that line, what lifetime are you expecting and what tolerance to
overload are you anticipating?

In other industries, where a catastrophic failure is unacceptable, the
standard practice is regular inspection and testing. In a past life,
I did some acoustic vibration analysis to predict conveyer belt
bearing failures. Lots of other tests for structural damage, cracks,
stresses, and corrosion, etc. Basically, one looks for something that
doesn't belong or has changed.

I don't see any of that in bicycling. I found a service that offers
bicycle CF "active thermography" inspection service in Germany:
http://carbon-bike-check.com (German)
http://www.infratec-infrared.com/thermography/application-area/active-thermography.html
Basically, they vibrate the frame with ultrasonic energy. Areas where
there are cracks become warmer, which can then be seen on an IR
camera.
http://carbon-bike-check.com/Motivation_1.jpg

This lack of testing really bugs me. Most CF owners do a visual
inspection and look for wrinkles in the paint or cracks. A few might
borrow some industrial inspection equipment:
http://www.olympus-ims.com
or shove a borescope/endoscope down the tube looking for potential
problems. I have a few of these:
http://www.ebay.com/itm/351973054942
The problem is that they only focus between approximately 2.5cm to
10cm. Good enough for automotive work, but not for pipe inspection.
I'm working on finding one with an adjustable focus and better depth
of field. Anyway, there are plenty of tools and toys to help with
inspection, but nobody that I know actually does it on a regular
schedule.

So, if you're going to buy into the CF club, and operate on the bitter
edge of mechanical failure to save a few grams, perhaps it might be
useful to find some inspection equipment and use it. It's much like
backing up a computah hard disk drive. Nobody expects it to fail, but
when it does, it can be catastrophic, happen without warning, and be
very expensive.


My club has 359 members this year and 80% have CF frames. I've been in
the club 6 years and membership fluctuates between 325 and 400 with a
fairly constant CF presence. The only CF frame or fork damage, not caused
by a crash that I've seen is one seat post that cracked forcing the rider
to do the last 20k of a century standing up. I've seen a couple frames
cracked but both were hit by cars, one from the rear and one T-Boned.

Why would I buy expensive equipment to test my frame? And I back up my
hard drives weekly.

--
duane

On 5/21/2017 12:58 PM, Duane wrote:

Why would I buy expensive equipment to test my frame? And I back up my
hard drives weekly.

Good idea.

A month ago my daughter's Thinkpad's drive crashed. Yesterday my son's
Thinkpad's drive crashed. I think I need to start replacing drives every
three years.