When I am wrong, I am wrong and not afraid to admit it. I have been posting on and off that I have three bikes, custom steel, Ti, and CF and as far as I can tell they feel pretty much the same. Not enough difference to talk about. Well in the last three days I have discovered that is BS. I rode the Ti bike on Friday and Sunday and the CF bike on Saturday. Essentially the same wheels, same tires, same inflation, very similar carbon bars, identical Al stems and CF seatposts (except for 27.2 on the CF and 31.8 on the Ti), and exactly the same saddle brand and model. The bikes are set up just as close to each other as I can manage in saddle setback, reach and drop. The route I rode was the same and featured some broken road and most importantly, several sets of railroad tracks. No comparison. Usually I stand over road irregularities, but this time I stayed seated over the tracks at about 17 mph. The Ti bike banged over the tracks and sent a strong shock right through to me. The CF bike was completely different. It nearly silently thump, thumped over the tracks and barely transmitted any shock at all. I was floored.

How could I have been so wrong? Well all I can figure is tend to stay on one bike for several weeks, many consecutive rides. When that bike needs some maintenance, I switch to the other one and keep riding it until it needs work. (I only ride the steelie rarely on special occasions.) And there may be a couple of days of downtime between the rides on the two different bikes. Also I have several routes and may not ride the same route on consecutive days when the bikes have been exchanged in between. So I would rarely get a head-to-head comparison. This just happened this time due to needing to true the wheels on both bikes in succession. So I rode them one after another. When I felt the difference after the first two rides, I switched back to the Ti bike to confirm. Yep!

Whatever the reason, I was wrong. It is plain as day. I don't think it was about the seat post difference. The behavior of the entire bikes on the railroad tracks and also on the broken streets was different.

FYI, the Ti bike is an Everti Falcon, a very stiff general-purpose racing model. The CF bike is a 2009 Giant TCR Advanced, just about their top frame at the time it was made. Both are plenty stiff for pedaling and handling purposes. I still love them both, but wow, have my eyes been opened!

I have never ridden CF but now have an AL w/cf fork and rear Masi and a steel Guru w/cf fork. I, like you, have not felt a big difference. But, having ridden the Guru exclusively for the past season I think I'll take the Masi out and see if there is a difference I can feel.

As long as you are willing to acknowledge that your findings are purely anecdotal and not scientific, then enjoy.

different chamois most likely.

You speak as if the only difference was in the material. But you can do anything with various materials. You can build a stiff or flexible bike out of any material. You can alter the balance between vertical and horizontal flex. So while material does make a difference, what matters is what the maker chose to do with that material.

Consider steel. Cars are built of steel, and trucks are built of steel. Does anybody think that they'd therefore ride the same?

What you write is true, but the takeaway here isn't about that. Its rather about the adaptability of humans. We as riders quickly adapt to any new 'norm' be it ride or handling. Yes there are ranges of characteristics for each material...and there may even be a more compliant Ti bike out there and a stiffer carbon bike...say like a S5 which is bone jarring stiff. But the point is, unless performing back to back testing with focus on certain attributes, we just ride and adapt. Now geometry in my experience is the exception. There may be some adaptability to different geometries but in my case as an old rider, too aggressive a geometry for a 30-50 mile ride will hurt my body versus a less aggressive geometry.

Thanks for that insight regarding the adaptability. Even with the explanation I gave, I wasn't really crystallizing that concept for myself or others. It makes me feel better to think that the error was due to a very natural human characteristic.

robert - welcome to the real world

Bingo!

Fully acknowledged. One point, one time. Anecdotes may not be data, but they are interesting.

Thanks, but do I have to like it?

Interesting that you have finally fine-tuned your kiester after all these years...

Personally I think with the cf you found a soft spot and tippy-toed over the tracks, myself, but, you know, I wasn't there so I can't swear by it.

Maybe it is like losing one of your senses and having the others become more acute. I just know next time I go in for a hearing test, I will need a hearing aid. And the ophthalmologist keeps telling me how surprised he is that the rapidly developing cataracts aren't causing me any problems (which they aren't yet). So maybe all my sensory perception is moving to my ass. Could be worse I guess.

How did you know. Was that you I saw hiding in the bushes?

It's good someone had said this earlier on the thread. I'm going to go over why certain materials are known for certain ride characteristics:

Steel is known for a buttery smooth ride because it's such a stiff material (high tensile strength). This makes for a commonly compliant ride over bumps because they make the tubes so small in comparison to others. It's so strong they don't have to use as much of it, and it makes the tubes more flexible in general.

Aluminum has the opposite appreciation for being so stiff, even though it's a softer material. The tubes are bigger, because aluminum is weaker. They make it bigger to be as strong as the steel lengthwise of the tube, but this happens to affect its strength in other ways as well. Aluminums density makes it so much lighter compared to steel.

Titanium isn't known for a ride quite as smooth as steel, or a rough as aluminum. This is because it's slightly weaker that steel (tensile wise), and slightly denser than aluminum. So you have tubes that typically range in size from steel to aluminum.

Carbon is known to be smooth and stiff. This is because it has many different properties, depending on which carbon material is used. The bigger reason it's so popular is how easy it is to work with to make shapes.

Shapes are a bigger factor in a bike's ride than material, and that's why they still make crit racers from steel and comfort bikes from aluminum.

Geometry?

merriam-webster's definition of Geometry:
Mathematics that deals with the deduction of the properties, measurement, and relationships of points, lines, angles, and figures in space from their defining conditions by means of certain assumed properties of space.

Geometry is the numbers you see on the fit guide of manufacturer's websites AND the shapes of tubes. It's the same part of science on how a bike rides.

As you can see the dictionary definition does NOT include the cycling sport usage we are discussing. Some folks find this usage of the term geometry a little peculiar. I have accepted it as a necessity of communicating with other cyclists, but I do think dimensions makes more sense. Better yet configuration. To my knowledge this is the only such use of the word geonetry to mean a specific design plan for something. I used to think there was only one geometry, that being the mathematical discipline itself. What is that they say, "You have to go along to get along."

I don't see the problem. Jargon often uses words in ways different than "standard" English. The language is fluid and words mean what speakers and listeners take them to mean.

I doubt there's anybody who doesn't know what's meant by "geometry" in the context of bicycle frames. In all fairness it's not a bad choice of words anyway, since we're talking about lines and angles.

IMO- "dimensions" in this context is a bit too limiting since many don't include angles when they think dimensions.

You don't seem to get it either. Cyclist tend to only think of 2 dimensional aspects (which is all you need for fitting except handlebars and saddles), but the 3rd dimension is a HUGE factor in how a bike handles. Geometry is 3 dimensional.

I've heard the phrases "front suspension geometry" and "rear suspension geometry" applied to cars (by auto engineers too). Never struck me as odd.

Good post and would say that 99% that ride bikes don't understand these relationships.

Actually the term geometry in the context of bicycles has really three different references often conflated:
1. Fit aka 3 pt contact of rider to the bike which includes stack and reach
2. Angles of the frame like sta, length/angle of seat stays and head tube angle and fork rake/trail etc that affect handling and ride compliancy.
3. Frame tubing cross-section...say aero versus round tube or asymmetric tubing of carbon and AL bikes versus more uniform steel and Ti which creates differential stiffness.

I have ridden thick walled, double OS steel which was buzzy and uncomfortable.

I have ridden large diameter aluminum which was buzzy and uncomfortable.

I have ridden heavy, large diameter titanium which was buzzy and uncomfortable.

I have ridden thinwalled standard diameter steel which was compliant and comfortable.

I have ridden small diameter aluminum which was compliant and comfortable.

I have ridden standard diameter titanium which was compliant and comfortable.

Material doesn't mean **** when it comes to comfort. Neither does geometry. And if comfort is really high up on your list, just fit 28mm tires and don't pump them up to 130 psi.