Eldron said:
On a personal level I agree - I have raced many bikes over years made from a variety of materials. There have been positives and negatives to all materials.
On a scientific level I have to disagree. You can make a carbon frame that is lighter, stronger AND stiffer than any stee/alu/alu frame. Thousands of websites/graphs/tensile tests/fatigue tests/comparisons will prove it.
Do we need all these superior trates? Some yes some no. Are we paying a hefty premium for very limited rewards? Yes - carbon probably only yields "real world" advantages of a few %.
Do I like them? Yes. Am I willing to pay the premium? Yes.
That's why I ride carbon and you ride steel & alu/carbon. It's the individuals choice...
Oh, you're going to bring science into the matter? Then please, using accepted methods, prove just how superior CF is to other frame materials. Note that as in science, the repsonsibility for proving a wild claim is that of the person making the wild claim....so have at it. And good luck.
You make claims about CF that are dodgy and pointless:
1. Great strength to weight ratio: and so what? Steel also exhibits a great strength to weight ratio. More important that than this ratio, though, is how the material is actually employed in the frame. As such, steel, aluminum, titanium, magnesium, et al all exceed very well their performance parameters.
2. Light weight: again, so what? The supposed "light weight" advantage is as specious as the advantage of low rotational moment of inertia. When the numbers are crunched--and if you have difficulty crunching the numbers, go to
Analytic Cycling, put numbers in their models, and see how little light weight matters when it comes to performance. Their models, by the way, have been verified by independent models done by MarkMcM at Weight Weenies, ScienceIsCool, myself, and others with actual scientific and engineering backgrounds.
And exactly how do you mean lighter? Is it's specific weight less? And what particular CF composite are you referring to? You are aware, aren't you, that they're not all the same, right?
And exactly lighter than what? Only an idiot would make a frame of steel and then turn around and use the exact same tubing dimensions, angles....all the same dimensions and parameters with the only difference being that instead of steel, CF is used. So is that the scenario you're talking about?
Just so you have a bit more knowledge to work with...especially compared to the very small resources that you seem to be using now....there are actually quite a few pros that are riding 17lb + frames on the Pro Tour. Hmmmm. Imagine that. These same pros can choose lighter frame options from their sponsors, yet they continue, at times, to use frames whose massive (and ain't 17lbs just massive?) weights must be keeping them off the podium....
3. Corrosion? Fatigue? You're kidding, right? I hope you're not going to pull out the old saw about how steel rusts......The unavoidable fact is that such concerns are not concerns to people that take very minimal care of their bikes. And if people can't even take minimal care of their bikes, then even the most hardy material won't protect them against their own ignorance. Alunimum may have the dodgiest fatigue characteristics, but that rarely is a problem for aluminum bikes. It really only becomes a problem when a rear dropout is bent, and for that reason, most Al bikes come w/ replaceable dropouts. Magnesium corrodes more easily than the other materials, yet pre-coating the magnesium bits effectively protects them for as long as the owner needs. CF also has its own issues. Material failures can be difficult to detect; CF generally does poorly in impact testing, especially in very localized impacts which are likely to only dent a metal tube. CF requires that owners pay more attention to their bike, potential damage, and etc. And if a guy or gal can't look after a steel bike well enough to keep it from rusting, then they're certainly not going to be able to look after a CF bike well enough to know when damage has been done or to known when more intense structural analysis is needed.
4.Exactly what range in a given CF parts vibration spectrum is the CF particularly good at damping? You might want to answer this carefully since it is known by people working in various disciplines that CF's response to certain vibrational spectra is very BAD for certain applications. Or maybe your generalization is just that: a really, stupid, generalization.
5. Stiffer means "which transmits more of my energy into forward motion..." Really? How? So you are going to allege that a force delivered to the pedal such that said force has components that aren't parallel to the vector defining the direction of motion...that such a force wouldn't exist on stiffer frame? Hmmmm. So is it the rider or the material generating the forces that don't act parallel to the direction of travel? Hmmm. That seems to violate everything that I learned in Newtonian Mechanics. That seems to violate much of what I learned in Engineering Dynamics...... Please, explain how your new science works.
Tell us, please, exactly where it is that your vast scientific and engineering knowledge come from....you know the knowledge with which you can make such extraordinary claims. If you're an engineer, then it's certainly valid for people to question your skills when you insist on using the applicability of CF in an aerospace application as proof, justification, or whatever for the use of CF in a bicycle. What's really bad about such "justifications" is that you never actually get around to making specific proofs, calculations, or demonstrations of how for a given set of criteria, CF would trump steel, Al, Mg, or Ti .
Then, because you can't make such proofs, you quickly retreat a few steps and say...."That's why I ride carbon and you ride steel & alu/carbon. It's the individuals choice..." Totally laughable.
Now look what you've done: propagated the ridiculous myth that you can actually race well on a "heavy, rust-prone, noodle" of a frame! 
