Carbon.

Tarckives Bikes
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“Only love is stronger than carbon.” --Fulvio Acquati, Deda Elementi from VeloNews

Seriously though, I feel like the “dangers” of carbon are immensely exaggerated by the cycling community in general. I’ve picked up this sentiment in a few threads here recently and some of the misconceptions bother me a bit so here’s my take.

Carbon is, obviously, a different type of material than steel and aluminum, with unique failure characteristics but it is not as if anything made of carbon will explode, at any minute, into a million tiny pieces. One problem is we are familiar with the ways in which metals fail. With steel it is generally deformation, with aluminum there is a mixture of deformation or brittle fracture due to overloading or fatigue. Where carbon is concerned things break more like wood, another fibrous material, which is an unexpected and foreign idea to some people.

If a carbon part is going to fail almost every time it will be due to crack propagation, so you know what to look for pre-failure, and chances are a crack isn’t going to start itself. A deep scratch, crash or severe overloading are probably the top three (in no particular order). If you watch for cracks in the same way you watch metal frames for bends and dents I see no reason to fear your componentry. Bonding failure is another, less common, failure mechanism but if you store your bike indoors and don’t leave it in a car or somewhere else extremely hot it should - for the most part - be ok.

The post-failure characteristics of steel are preferable to those of carbon - to be sure - but carbon is not going to shatter like a pane of glass. Take for example Backstedt riding deep section carbon wheels in the Paris-Roubaix, which was quite stupid but that is beside the point. On his website he says:

He rode carbon rims, they broke, yet did not erupt in a shower of carbon fragments and throw him to the ground. Hincapie broke his carbon wheel too this year but Backstedt broke a regular rim last year. Clearly carbon is not the proper material under these circumstances, something with more resilience should be used since the loading on cobbles is so unpredictable and severe.

To summarize, look for cracks instead of dents/bends. Carbon is safe.

As a mechanical engineer thats my take, but feel free to believe whatever you want. :colbert:

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well put.

i have a carbon fork on my scat and a carbon seatpost on my kilo.

don’t misuse parts and they probably won’t break. carbon is great at doing what it’s designed for. it’s when you use it for something tougher that it breaks, much like anything else. it’s harder and more expensive to overbuild carbon than it is to overbuild metals.

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Carbon wheels at the Paris-Roubaix is just stupid, especially when you’re a 200+ pound equipment-destroyer like Hincapie. I almost feel like he rode carbon wheels because he knew that they’d implode and the pressure would be off him to win.

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Carbon: useful for some things, not for others.

Unfortunately “carbon” is a stupid industry buzzword now so I am going to make fun of it any chance I can get even though I use some carbon items.

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I dig me some CF, but I’ll always be weary of CF seatposts after seeing a buddy’s sweet stitches than ran up his thigh into his crotch.

FWIW, he probably overtightened the post and caused a ton of unnecessary strain on it, but that still freaks me out.

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While the average recreational cyclist doesn’t ride Roubaix-like cobbles every day he/she can expect some “unpredictable and severe” jolts as part of normal riding. It adds up.

With regular inspections and common sense carbon is fine material. It doesn’t mean it’s right for every situation or every rider.

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I think Hincapie is 165lbs but either rate, it’s a bad call to use carbon rims on the PR. FWIW, nothing carbon that I own has broken on me.

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My road bike = as many nice carbon components as I can afford
My fixed gear = gets thrown on the ground too much for CF, but I do have a lot of trust in my old composite wheel. Enough so that I run it on the front and do all sorts of BMX shit that would probably make a lot of you frown.

Anyone see King of Skitch at the bike film fest? That last shot is priceless.

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It should be noted that Carbon will fail in extreme situations where other materials will survive! I was riding my 3rd or 4th crit when a crash in front of me sent me hard to my helmet, and my carbon framed bike cartwheeling down the street. In addition to a broken derailer hanger, I ended up with a cracked chain stay. I would say without a doubt that had I been on my old steel frame, or my cheap aluminum replacement frame, the bike would not of been destroyed.

This has more to do with understanding the situation you are in… If you are not prepared to replace your carbon frame… DONT RACE IT! I learned that one the hard way…

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dude, I would not use any cartwheeled frame. Carbon or otherwise.

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Yeah, I really doubt that an aluminum frame would have survived that crash. Steel could probably be alright, but probably only after it had been examined and possibly straightened by a mechanic.

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Really, everyone should get into the mentality that bike parts are basically disposable. Ride them into the ground, and be ready to replace as needed. Broken parts mend better than broken hearts.

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I know what you’re saying, but I don’t agree that they should be thought up as “disposable”. Use them for their full life span, then replace before you fuck up your bike or your body.

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If it can’t be fixed with a hammer I want no part of it.

(I’m only sort of joking. I own no CF parts and don’t plan to. I enjoy steel. It’s cheaper, too. I’d take a carbon bike for free though.)

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Modern steel is often anything but cheap.

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[quote=“def”]
Take for example Backstedt riding deep section carbon wheels in the Paris-Roubaix, which was quite stupid but that is beside the point.[/quote]

I think that is the point. I ride over multiple train and tram tracks every day and over a number of cobble strips at the entrance to streets. If money was no object, maybe I would consider carbon but I don’t want to risk (even if it’s one in a million - which it probably is) losing an expensive frame or wheel just riding on normal city streets.

Also, I’m scared of the effects of UV on carbon. Let’s wait a few years and see how many folks are riding on 30+ year old carbon frames or wheels. I can’t look at bikes as disposable.

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qft

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[quote=“wotan”][quote=“def”]
Take for example Backstedt riding deep section carbon wheels in the Paris-Roubaix, which was quite stupid but that is beside the point.[/quote]

I think that is the point. I ride over multiple train and tram tracks every day and over a number of cobble strips at the entrance to streets. If money was no object, maybe I would consider carbon but I don’t want to risk (even if it’s one in a million - which it probably is) losing an expensive frame or wheel just riding on normal city streets.

Also, I’m scared of the effects of UV on carbon. Let’s wait a few years and see how many folks are riding on 30+ year old carbon frames or wheels. I can’t look at bikes as disposable.[/quote]

No matter what component you are considering the material and model should be chosen for the riding conditions. Most carbon rims are designed to be aero and lightweight for riding on smooth pavement and just as you would choose between tandem, touring or racing wheels depending on their intended use the same logic should be applied to carbon wheels. If you are going to be riding on bad roads or over tracks and into dogs, carbon wheels, at this point, aren’t designed for it and are probably not up to the challenge. When they start making carbon tandem wheels then buy those.

As far as UV, this is a good point. Some of the resins used are sensitive to UV or other environmental factors which is why I mentioned storing carbon parts indoors in my previous post. I’m sure this will be addressed in the next few years. UV protective films already exist but they are expensive.

By the way, I love steel, I have two steel bikes. I just don’t think carbon deserves the bad rap it gets sometimes. Also, I understand wanting a frame that is easy to repair. Steel is awesome and will never go away.

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aluminium (in the case of a frame) will very VERY rarely deform. Usually, it cracks, in a high stress area like under the headtube. I ride street mountainbike, and ive seen hairlines take off a headtube bunnyhopping off a curb on aluminium frames. if youre doing any sort of unusually strenuous riding(read: “tricking”) you should ride steel. I can definately understand aluminiums place in touring bikes though, or racing bikes, especially if the coure has already been planned, and you know whats ahead. and carbon definately makes sense on the track and whatnot.

but for a bike thats gonna get ridden in traffic, or in alot of unpredictable circumstances,or tricked on. i wouldnt trade steel for the world.

also theres extra comfort riding steel in knowing that if something does start to fuck up, youll get lots of advance warning, and it may even be fixable!(try bending back that carbon or aluminium frame)

and now to throw a wrench into the works…what do you guys think about titanium?