rpenmanparker 

Your analysis isn't wrong, but I think your take-away is. How would you provide an accurate answer to the question? Test every carbon bike? Provide anecdotal information as is so popular on the 41? Such as, "Well my carbon bike made me faster." It is a nearly impossible task, but I think testing the CF bike that is most highly regarded for speed against similarly reputed bikes of other materials is about the best that can be done as a first approximation. Limiting the variables as much as possible to only the frame is just further simplification. Never fear, there is plenty of complication to be worked into the database down the road.

wphamilton

Now that suggests an interesting test with useful results for questions like these. Blind A-B tests of riders, using bikes known to be unequal or identical, to determine the probability that a rider really could tell the difference. Then data from first hand accounts could be weighted to appropriate confidence intervals.

Or you could take it with a grain of salt, and note that a large preponderance indicates a likely result.

Homebrew01

Some of us suggest that rigorous testing protocols may show if one frame material enables a bike to go faster than a different frame material.

Others think that riders can feel the difference, and we should accept their "feeling" as a conclusion.

OK, difference of opinion here I guess.

tonski 

It looks like he's saying that you're putting artificial constraints on the OPs question. Don't really know for sure though and the "study" is flawed anyway, if you wanted to know if you'd ride faster the riders would need to ride at the same W every day to ensure a valid test, since the OPs W is presumably the same day to day

coasting 

i do go faster on my carbon.

HiFiGuy1

Interesting question, and one without a simple answer. I can say that I personally rode a Felt Z4 carbon bike after riding a Felt Z85, which is a decent practical comparison between carbon and aluminum, with the same geometry by the same manufacturer but different materials. I was certainly able to ride more quickly on the Z4 because it was less jarring, so I felt better pressing harder. The ride was more comfortable, so I was more comfortable riding at a higher speed. Is the carbon frame itself "faster" than it's aluminum brother? Not likely. Did it allow ME to go faster? Definitely.

Homebrew01

Yes, it would be very difficult to actually carry out a valid test. But saying "I feel faster" is not much of an answer. At least testing, if possible, would give a legitimate answer.

You'd need to set up a robot cyclist, putting out a constant wattage, in an indoor velodrome, on the various bikes, then measure the elapsed distance after a specific time.

coasting 

i don't just feel faster. i am faster by half an hour over 100 miles.

Homebrew01

How many centuries have you ridden on each bike ?
And what are the differences between your bikes : Wheels ? Tire pressure? Fit ? Body aerodynamics ? Weather conditions ? # of poops each day ? sleep the night before ? hydration ? nutrition ? Were you on the drops/hoods/ tops the exact same amount on both bikes ?

Plenty of factors than can have a cumulative effect.

coasting 

back when i was in london i would do a century each month if i had the time. i did this when i hd the steel and first got into cycling and after i got the carbon.

the faster carbon rides are consistent.

HiFiGuy1

Well, to be fair, it's not much of a question, now is it? Empirically speaking, at least. And I certainly didn't say my answer was definitive by any stretch, but just a simple observation of two otherwise very similar bikes by one rider on the same day on the same route. It is, of course, subjective.

The truth is, almost any scenario can be picked apart. The problem with a velodrome, in your example, is that it would essentially be constant speed, as offered by constant wattage from a robot. So except for the initial acceleration, there wouldn't really be much in it, because after that the bike would reach steady state, and unless one or the other were significantly "lossy" due to flexure, they would be roughly the same. The reality is that you would need to engineer two largely identical frames to have the same deflections under constant load, and basically test them under dynamic load with your robot, to see if they performed differently dynamically. The lore of a Ti frame, for example, is that under small deflections the frame will "give", but Ti stiffens under larger deflections, so it rides comfortably over road imperfections, but is responsive when accelerating or climbing.

Now, a robot that could ride all the hills and descents and flats of the Tour de France by itself, once with a steel or aluminum frame, and once with a carbon frame, that would be a start. You think Google would hook us up with the test equipment?

Homebrew01

Miguel Indurain ?

e_guevara

From the OP first post:

He apparently knows what constitutes a bike - frame, wheels, and components.

You can choose a particular bike geometry depending on your intended use, or for comfort reasons, without going custom. As for positioning, a good LBS can get you into a "good enough" fit. You can go to a reputable fitter if need be. Positioning helps, but you can do it on your old bike first and see if it improves your riding. Aside from weight and comfort, what benefit can components (handlebars, stem, seatpost, saddle) provide that relates to being "faster"?

Aero tube shapes can be done with aluminum through hydroforming, but not so in steel. As far as structural characteristics is concerned, aluminum and steel are stiff enough. Where CF trumps aluminum or steel is in it's stiffness-to-weight and the ability to "tune" the system. But tuning can also be done on aluminum or steel but not as good as with carbon.

Specialized Allez is sold with DA 9000, Cannondale CAAD10 Black Inc. is with Red22, and Giant TCR SLR is with Ultegra. Isn't that comparable to what high-end carbon bikes are spec'd with?

HiFiGuy1

rpenmanparker 

I should say that I accept all the implications of using a particular material in producing a faster or slower result. So CF's ability to be shaped to a greater degree as well as laid up with complexity not possible in the metals would be necessarily inherent in the frame chosen and the result obtained. I regard that as a component of what we mean when we say CF bike. Same for the relative limitations of each of the metals.

jaggededge

Every persons situation is different. For me going from a late 60's steel bike to a average weight carbon bike has been a huge difference.
Now that I have my legs under me after 4 rides I've attained a goal I was trying to meet on my old bike; 20 miles in an hour.

RJM

I gained two miles per hour going from one steel bike to another steel bike. I believe the speed improvement comes from wheels and body positioning on the newer steel bike with the positioning being a combination of fit and design geometry. The weight is a couple of pounds difference, but climbs are not the only place I am seeing gains. I'm faster on the new steel than on an older carbon Madone I owned.

I think that buying yourself a good bike will help you improve your speed, be it steel, aluminum, ti, or carbon, but don't buy that frame material will automatically make you faster.

darb85

at elite levels? maybe? But My Biggest noticed change is fatigue from my aluminum bike. much less. Its quite noticable. Frame was the only change in my case.

coasting 

a lot of people in denial.

Lazyass

Let me ask this for the second time. In what way did the frame material allow you to ride 100 miles 30 minutes quicker?

coasting 

what makes you think it didnt?

coasting 

one thing that was noticeable was my arse was more comfy and i didnt have to ease off to stand up as often.

merlinextraligh

A high end CF frame is going to be faster than a steel frame for several reasons. Problem is that the difference is pretty darn small.

My perosnal points of reference would be to compare my OS Paramount, with my Wilier. The OS Paramount used shaped oversized tubes, and still is fairly close to state of the art for steel racing bikes.

The Wilier frame and fork is almost 3 pounds lighter than the Paramount's frame and fork.

3lbs will save you about 1 minute on an 5 mile, 8 percent grade.

The 3lbs will also save you some energy, or increase your speed a touch, every time you have to accelerate from a stop, or out of a curve, or to respond to a surge. The difference again is very small, but over the course of a long race can add up.

Biggest difference for me in speed, is that the stiffness of the front end increases my confidence descending and cornering, which allows me to go faster into corners. I'm sure you could corner as fast on the comparitvely flexy steel bike, but in practice, the confidence that the Wilier inspires results in me going faster.

There also may be a small difference in efficiency in the transfer of power from a stiffer bb, although that is subject to debate.

Net, net, there are small, but real advantages to the CF frame. However, anecdotal reports that "my speed increased 2 mph" are either fantasy, placebo, position change, calibration error or a combination therof.

knobster

I had a Bianchi EV Boron that had shaped tubes. It was steel.

Lazyass

Because I've had a carbon bike ('06 Giant TCR Composite 2) and I know that it will not instantly drop 30 minutes on a century ride. Some of you act like it's like riding a dual suspension bike or something. It's still a fully rigid bike.