I know there is no definitive answer to this, but I think I will get some good attempts…
If I have two bikes, one made of 100% aluminum, and one of carbon fiber AND the bikes have the same aerodynamic and physical qualities (weight and stiffness) how much time would you surmise one might gain over the course of 112 miles (and maybe later in the marathon) simply from the likely vibration dampening properties of carbon fiber?
I am looking for a number, here. Take a stab.
Thanks, everyone.
Cheers.
nothing scientific here but, off the top of my head, I’d see no reason to pick up any time on the bike since weight and aerodynamics are stated to be the same, unless road conditions are bad. This could be a factor. The vibration damping of CF over aluminum might reduce fatigue toward the end of the ride on rough roads and could also possibly contribute to a better run split by saving some wear and tear on the legs
Zero
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What is the brand of your aluminum bike?
Impossible question.
you can make Al ride soft as mush, and CF ride like a rock. It is not really the material that makes the difference, but how it is made.
IMHO - The bike split should be very similar if the road surface is good for Olympic & shorter. If the roads are bad & the distance longer than Sprint distance, I think the carbon would have a significant edge. I feel that my run split is much better coming off my T14 with a carbon rear than an all metal rear.
That being said, carbon is just a material. How it’s used makes a huge difference (Fiber make/model, number of layers, resin used, molding process, orientation of layups with respect to one another, shape, etc.). With my T14 the head tube/BB/chain stays are set up to be super stiff. The seat stay is set up like the fork to soak up road vibration before it gets to me & ultimately fatigues my legs. The reason I mention this is that some manufactures treat the whole frame the same way & don’t really maximize the potential of the material (carbon).
I realize it is impossible. Of course it is.
I was thinking that it might reduce fatigue, as I think there might be a tendancy to tense up your core when you hit a lot of vibration.
I ride a 04 Felt, and am considering moving to a carbon bike, and wanted to control for the design and just focus on the material and ask myself ‘what do I stand to gain?’.
it would also need to have the same saddle and wheel set up. If you were susceptible to comfort issues one may be better than the other but bear this in mind - it’s not the material, it’s how you apply it. This ‘aluminium is stiff’ and ‘carbon fibre damps road vibration’ is a dis-service to engineers who ‘tune’ a materials profile and section to it’s application.
Of course, same everything. Same clothes, too. Same day, same tempature. It’s just a ginat hypothetical ironman.
Everyone seems to be focusing on the manner in which the carbon is layed-up…so…let’s say that the carbon has been configured for optimal vibration dampaning and stiffness -or as well as the major manufacturers can do it today.
The one generalization you can make about frame materials is: You cannot make generalizations about frame material.
There is simply too much difference from brand to brand, model to model. Materials like carbon fiber is so engineerable that any generalization is inaccurate.
Thats my point… what is optimal ? The whole benefit of carbon fibre at a performance level is that it can be tuned to the individuals riders requirements so this makes your question ambiguous. F1 cars are a classic example of this.
If however, you asked if you built a compliant bike versus a stiff one (irrespective of material) it will come down to determining where the absorption comes from and any resultant power loss. If this sounds over complicated it’s supposed to - you only have to look at the hours a good engineer will spend weighing up decisions like these.
That said if you fancy an anecdote, take a look at softrides website take on beam bikes and their advantages.
So what specific models offer the best combination of comfort and power transfer?
It depends on the individual rider and their biomechanical needs.
I was hoping to avoid a contrarian’s debate, but perhaps I asked for it. It’s ridiculous, and I know that. No one’s answer is going to be used in a court of law, and I am just asking for people gut feeling or even an anecdote (which is often a lousy thing to base a decisions on, I realize).
It is often stated that aluminum is a good transmitter of vibration of road noise. It is also widely stated that Ti and Carbon are vibration and road noise resistant. I am sure it is possible to create a bike that is better or worse at this than others. Material isn’t really even germane, so much as an imaginary bike that dampens vibration, and that does to a lesser extent. That’s my real question, I guess.
I have a Felt S22, I am positioned fairly well on it, and have been fairly fast on it. My seat is not too high. I am thinking of buying a carbon bike and would like to know someone’s estimation (a guess even) of how much time could be gained from such a change that could not be attributed to aerodynamics or weight, etc. In short would the dampening properties make me faster or fresher for the run? Certainly we are all faster on the same bike on a flat road than on a bumby road (under the same conditions), right? If you need a list of the bike I am considering, here they are:
Cervelo P2c
QR Seduza Giant
Trinity Carbon
I know there are a ton of other differences in every little change, but I am strictly interested in the advantage of possible dampening gains. Thanks, everyone.
you could also change vibration dampening by changing wheels, seat, stem, bar tape, tires, tire pressure… I’ve ridden carbon, steel, and aluminum and notice the most difference from changing tire pressure by 10psi.
I’ll let the engineer’s chime in…but it’s always been my understanding that the wheels/tires account WAY more of the compliance than the frame.
Interesting thought, but perhaps one of those great “myths” regarding buying a new bike.
anecdotally speaking ?
Most comfortable bike ever for me: Kuota Kalibur
Stiffest under power transfer ?: my Giant TCR track bike (I could never ride it on the road, it would hurt like hell).
A difference in comfort or in resultant overall speed?
not only is there no definitive answer, the parameters aren’t specific enough to provide any type of usable range.
When comparing materials, the only REAL way is to compare materials, geometries, etc. from the same builder. You say you have a Felt, so perhaps you need to ride a Felt carbon (based on the same geometry and with all the same components as you’ve mentioned). While there is enough data on aerodynamics, I don’t believe there have been many studies (enough where you could extrapolate information to gain a general idea) on time savings vs. vibration dampening.
What I read into your post is the idea that you are looking to become more comfortable on the bike, so you can possibly have a better bike split, but more importantly, allow you to feel a bit better when getting off the bike for your marathon? First question is, have you gone to someone who can help you obtain your optimal position on your existing bike? Is it still not comfortable? What would be your “time advantage” threshold that would make you buy something new? 0-60 seconds? 5 minutes?
Sorry, but this is data that is not only sparce, but irrelevant.
I am not actually looking for a definitive answer, only a thoughtful, yet arbitrary guess.
I don’t actually don’t care that much about comfort, so much as not making myself uncomfortable to the point that I am actually slower. The goal is speed.
I am reasonably comfortable on the Felt as positioned by my tri-specific bike shop, but aren’t we all looking for more, better, faster?
I appreciate everyone’s enthusiasm for this.