rydabent

Posted on my facebook page which has several members in cycling was this bit of information. In professional racing, riders are experiencing sudden failure of their carbon frames. It was reported that the failure is so complete, and the frame usually shatters so completely that the frame can be sent back in a small box not much bigger than a box for the wheels. These high end bikes are called "carbon frames" but are little more than some carbon fiber imbedded in plastic. It would be more accurate to call them plastic bikes. In the Tour, almost all pile ups call for a new bike. The days of just straighting out the handle bars on their metal bikes and getting on with the race are long gone.

The dirty little secret here is that racers are pretty much told to keep quiet since the bikes they are given are provided by big name bicycle mfg, and if they speak out, they would be out of racing. The fact here is the mfg make huge profits selling plastic bikes to the wanna be racer boys at very high prices. It all boils down to money as most things do.

BTW I expect to get a lot of hate mail from mfg reps who wont admit who they are, and bike shop owners to also make good money selling the "latest most wonderful" bikes.

bikemig 

That is not quite what the NY times article said (I'm assuming the OP is referencing that article). The article pointed out that some riders reported frame failures . The one important take away from that article is that carbon fiber is a great material if you can trust the manufacturer. Given the importance most riders assign to low weight and the economic pressure to keep costs lows, there is a question (and the article quoted an industry insider on this) about how reliable carbon fiber might be for ordinary riders. The "dirty" secret, though, is economics 101 not anything specific to carbon.

This post, I suspect, is designed to start a food fight. This is a url to the article which is not as apocalyptic as the OP suggests:

https://www.nytimes.com/2014/07/27/sp...rder.html?_r=0

trailangel

Ha! I just want to know why everybody is wearing white shoes?
Looks like they are riding their bikes on the way to a golf game.

rydabent

bikemig

Yes---I believe that was the piece my friend was using. The fact remains metal usually cracks and bends, CF shatters, and you are on the ground instantly.

IMO the problem here is this is a case of the "weight weenies" going over board, and making CF frames too light. Note that the UCI that I dont agree with much at all, has put a minimum weight on racing bikes.

pvillemasher

Professional road racing? Reported by whom?
I watched a lot of the TDF this year (50%?) and I saw one broken bike (Contador's). There were a lot of crashes, and most times the guy got back on and rode away. Never did I see anything that resembled "shattered" or anything similar.

MRT2

True, but I would be curious how many complete bikes (wheels and components included) that started the Tour actually completed the TDF.

Northwestrider

An interesting article, that makes it easier for me to stay with my heavier steel framed Surly. :-)

Pibber

This one time, an older woman called my SR a "crackanfail", an allusion, I imagine, to the supposed weakness of aluminum. I laughed in her face, actually, and explained the bike had survived being hit by a car(sadly with me on it) and hadn't so much as been dented.

Yes, some alu frames have broken, much like some steel frames have as well.

I especially like the part where the doctor says the bikes "completely explode"......

rebel1916

Technically, carbon doesn't explode. It asplodes.

RPK79

I heard they had some boy scouts at the back of the race sweeping up the carbon bits much like at a parade where they sweep up the horse droppings.

howsteepisit

If Cf bikes sold to the public (non-racers) were in any way failing unexpectedly the CPSC and the civil court system would have or will eliminate the offending maker of CF bikes. OTOH, bikes used in competition are expected to be cutting edge and subject to some level of failure due to that. However, if the failure rate were excessive lawsuits would control that too. \\Note the above comments relate to the US market only, I don't know the liability laws of other countries.

awfulwaffle 

I suppose that we had better stop using carbon composites in aircraft, too, given that they're made by a similar process using epoxy impregnated weaves. Forget the mechanical properties, epoxy is a polymer so it must lead to exploding frames!

wnl256

Why? Do you plan on riding like they do in the Tour?

Frame failures in the Tour are representative of .... frame failures in the Tour. They might be representative of frame failures in other grand tour races, but they certainly don't reflect usage anywhere else, including and especially the vast majority of non-professional riders.

pvillemasher

Then that data would need to be compared with past data from when steel bikes were used.

Lone

Those Formula 1 cars are worth like a half Billion dollars. If I hadn't of started liking Formula 1, I would believe you.

squirtdad

Carbon fiber frames are not plastic (inflammatory statement there imho) They are a composite material with fibers (carbon) in a matrix of epoxy. there is a log of design in areas like thickness for composite, fiber alignment, material mix for provide strength, stiffness, good ride, light weight. Proper construction uses tech like air bagging to ensure the minimum amount resign in the fibers.

The finished product can be as strong or light as designed.

That said the failure mode is quite different than it is for steel. The structural integrity depends on the whole, not individual parts. When a single area fails the overall strength radically reduced and the failure tends to be immediate and fast. Where the initial failure is make as differende also...if it is an area that is stressed, the overall reduction in structural integrity is fast.

as an imperfect example think of a pice of string...... if it is stretched tightly between two points and you nick it with a knife the reduction in string structure will cause the string to break, even if it was not cut all the way through.

There is plenty of documentation about carbon frames and forks failing and people getting bikes replaced under warranty

What does this mean practically?

Carbon is not going to blow up if you sit on it and ride it.

Carbon does take a little extra TLC

People with carbon frames, especially those that get used hard, should inspect them regularly for things like cracks, dent and large nicks

I would suggest the history of carbon has enough issues that you should only buy a carbon bike with a valid warranty, which pretty much means new


also to note comparing a bike to an airplane or even a fi car is not really valid....way different engineering issues

Personally I like steel, but that is more style than material

-=(8)=-

I built carbon fiber parts for race cars(below). I saw it from the mold to coming in after hitting something. To me, it's all about the guy mixing the resin. There are many variables involved in that to take into consideration. Get it right, its strong as iron ~ off just a little . . . Oh well, uh oh!!
I have mixed feelings about it. I don't know if I would want my bike to be made of it. I have a hard enough time with the bike I have that has a CF fork

ItsJustMe

I know nothing about high end materials. Is CF really better than titanium? Seems like Ti would be stiffer.

mconlonx

Holy crap, Rydabent trolling hard outside the Helmet Thread...

I work in a Trek shop, so I suppose I would be on of those "mfg reps who wont admit who they are, and bike shop owners" except I am neither, don't own or ride a CF bike, have absolutely nothing invested in the CF issue.

There are no more warrantly claims for CF bikes than there are for metal bikes. Pro racers ride bikes harder than your average bear -- they'd be breaking metal frames at the same rate. And still, the vast majority of their bikes don't break.

genec

By definition alone, CF bikes are indeed "plastic." Certainly all the resin systems I learned about in college came under the heading "plastics."

BTW there is a different definition for "plastic" (as in flexible) than for "plastics" (the materials).

Yeah, I know... semantic argument...

spare_wheel

carbon fiber fabric is not a "plastic".
epoxy can be a "plastic".

a laminate made of carbon fiber and epoxy is a laminate, not a plastic.


i've been commuting on carbon fiber for 8 years and i love it. i will likely never buy a steel or aluminum bike again.

B. Carfree

I thought the UCI mandated that bikes used in competition had to be available to the general public.

I agree that if CF bikes were failing at significantly higher rates than other materials then the CPSC and court system, as well as corporate bottom lines and consumer fears, would eliminate the problematic processes.

Number400

I believe that one of the main points of the NYT article that is missed here was that riders are reporting more injuries because of the way that carbon bikes fail (or don't fail) in a crash, not because they fail more often or unexpectedly. In a pile up, bent forks wheels and even top tubes were common and now, not so much. The fact that a wheel, fork and frame are all carbon and do not buckle or absorb impacts as well as metals is what is being blamed for throwing riders down into the pavement a lot harder than they would be on a bike that bends.

Not to worry, I am sure that manufacturers will soon be being putting foam crumple zones into bikes to absorb impacts better and making them safer for the Pros. This will filter down to our bikes too. After all, bikes unlike cars, are not designed to crash but in my opinion they should be.

spare_wheel

thermoplastic and kevlar can make composites more impact resistant than thin metal tubing. this military technology is starting to appear in bike components.

Coal Buster

The carbon fiber epoxy mix is a plastic in the sense of the word meaning light weight and moldable, which it certainly is. It's not moldable once it sets but neither are thermoplastics. Made-of-Plastic is not a perjorative, although the author probably meant it that way, it just a word that fits. No big deal.