Eric F

We know how CF bike frames age. CF is not a new material. It does just fine. A decently built CF frame is pretty likely to last longer than your lifetime.

Riding comfort of a bicycle is affected more by other things like tires and proper fit than it is frame material. Also, not all frames of the same material have the same ride feel. How the material is manipulated (thickness, shape, etc.) effects compliance/stiffness.

Repair of a damaged/broken steel frame isn't generally going to be something your LBS can handle. It's going to need to go to someone who specializes in that kind of work, and knows what they are doing. This is exactly the same for CF frames.

alcjphil

A few years ago, our club hosted and organized a 40 km individual time trial. The age category that had the most riders doing the 40 km in under 1 hour was the 50-59 age group

3alarmer 

...I know I will be pilloried here for suggesting this, but one of the earliest bikes pitched for sale to the triathlon demographic was the Centurion Ironman (sometimes encountered in the Dave Scott autograph edition.) There is an entire thread on these bikes, and the way people have upgraded them to go faster. It was, at the time, a very solidly made Asian production frame, relatively light for steel of the time, and with a forgiving geometry that is good for that longer 112 mile ironman distance, but still quick enough to ride a decent bike leg at the speeds you're talking about.

As was suggested earlier, the most bang for your buck in making any bicycle go faster is in your wheels and tires.

The Ironman series was a big seller for Centurion, and there are a boatload of the lying around, selling cheaply enough on Craigslist, that you can afford to customize one with modern wheels and gearing. Some of them have already had these modifications made, as you can see from looking at the thread. It runs for over 400 pages. One of the advantages is that they made and sold so many of them, they are readily available in smaller sizes. Another is that it is has very little in the way of proprietary technology, so they're easily modified. It will never be as light as a CF frame, but they can be built up to be a machine that goes pretty fast, with the right wheels and gearing. And the ones I've reworked and ridden are nice, neutral handling bicycles. Not stiff at all, so less abusive to your body on longer distances. But slower than a stiff frame. If you are just doing this for personal satisfaction, and don't plan on finishing in the top tier for your age group, you might want to check one out. It's definitely a "triathlon bike". Might be the original triathlon bike.

Lombard

This is very misleading. The rolling weight argument is way overblown. Sure, less rolling weight will make you accelerate faster and therefore make you feel faster. However, once up to speed, weight is weight.

3alarmer 

...not sure what you're saying here by "rolling weight", but reducing rotating weight in the wheels and tires has a long history in both bicycling and motor sports. The physics and math behind it are sound, and it's not misleading to state it as a basic principle. If, OTOH, you're talking about the total weight of the bicycle frame package, I tend to agree that a modest increase in frame weight is probably not going to make people that much slower over long distances, unless the distances are uphill. Again, the physics and math on this are pretty straightforward.

Eric F

For a tri bike, I would agree that rolling weight of wheels is probably not a big factor. However, you're excluding the more important part - aerodynamics.

Lombard

Correct. For a tri bike, aerodynamics will be much more important than weight of any kind - rotating or otherwise.

Lombard

By rolling, I meant rotating. And no, once up to speed, your momentum will make it such that weight will be weight will be weight.

3alarmer 

...again, if we are talking about the rolling weight of the package, there is a little, but probably not substantial difference created by 6 or 8 pounds. But if you're talking rotating weight of the wheels and tires, there's a significant energy input not only to get them up to speed, but in keeping them rotating at that speed. This, of course, is in addition to aerodynamics of the wheel and rider positioning. There's been some back and forth transposition of "Time Trial" bike versus "Tri" bike in this thread. Are they now used synonymously ? Because I saw zero time trial frames at that Ironman tent, and I cannot picture riding a time trial frame for 112 miles and living through the experience.

Eric F

Lombard's 3alarmer's post about wheels and tires did not make any mention of weight. He seemed to be echoing my earlier suggestion to VegasJen about investing in aero wheels.

EDIT: Fixed.

tomato coupe

It takes very little extra power to keep a heavier set of wheels rotating at a given speed than a lighter set of wheels. And, the extra amount of energy required to get a heavier set of wheels up to a given speed isn't very much.

3alarmer 

...while the forces we are discussing certainly are less than aerodynamics (probably by a factor of ten), that does not mean this statement you have just made is correct. Here is a long blog post about the subject. I'm not prepared or willing to argue it with you, because you give the impression that you are another true believer. I don't argue on Bike Forms with true believers, but I occasionally throw them a link. This is the same stuff that people argue endlessly, in road, about how wider tires are actually faster (even if they are heavier and run at lower pressures), and I realize that discussion of such topics simply wastes both your time and mine, You have misinterpreted some of the results coming out of the improvements with modern wheel aerodynamics as invalidating the established rotational weight dynamics, simply because they are a greater order of magnituce.

Fortunately, upgrading the wheels on an older bike to make it go faster is still OK advice, because the wheel upgrade will include both aspects. It's not a choice between one or the other.

3alarmer 

...my bad. I somehow misinterpreted "rolling weight" as a reference to weight. I'll try to do better in the future.

Eric F

An anecdotal experience...Back in the early-'00s, when I was a racer-boy, I borrowed a friends set of Mavic Cosmic Carbone wheels for a few races. They were pretty heavy, and kind of beastly for crit racing, but when they got spun up over 30mph, the flywheel effect was noticeable, and they really wanted to fly. In long sprints (ramping up to over 40mph), it felt like they were pulling me along. I can't say that they were faster than light and aero wheels. All that mattered to me was being faster than everyone else on that day. They were definitely a different feeling than light wheels, though. A little later on, I had a set of Zipp 303s that were quite light (by the standards of that era), but I hated the way they felt in a sprint - like there was no foundation to work from.

3alarmer 

...this is what happens whenever I discuss stuff like this here with people who never rode a set of steel bicycle rims.
Younger people are so spoiled by modern rim technologies, that you have lost sight of the significant advances made in this area, and why they were accomplished.

And I don't even think you are that young.

Eric F

You're good. I meant to mention you, not Lombard.

tomato coupe

It doesn't matter what the wheels are made of. It takes very little extra power to keep a heavier set of wheels rotating at a given speed than a lighter set of wheels. That's physics.

VegasJen

Well, this conversation is going off the rails. Not even my fault!

tomato coupe

No, it's on you. You should have anticipated every possible tangent that the thread might take before you started the thread.

Eric F

It's totally your fault! You have clearly made up your mind that you want a carbon tri bike. If you won't leave the door open to other options, we have to find something else to talk about.

rsbob 

Interesting link. Thanks for posting even if it wasn’t for me. Since I just purchased my birthday/x-mas gift, a set of aero, low weight wheels, the link was validating.

Jrasero

This is a hot take for some but I never buy used carbon bikes. Bikes don't have odometers and carbon is insanely good in hiding damage. There is a good chance any used carbon bike you buy is "fine" but fine and my collarbone and front teeth are a little more skeptic. I specially draw the line in buying used carbon bikes when I am spending thousands of dollars to begin with. If you are just starting out or on a super strict budget and you get an amazing deal sure, maybe.. but even then I'd trust a Chinese carbon frame over some random persons carbon bike

3alarmer 

...this forum is all about validation. Happy I could help. You needed those wheels.

3alarmer 

...the problem in me discussing this with most of the people here, is that they have never ridden on steel rims. The changes have been incremental, and a lot of the stuff you've read online about it has been comparisons between wheel sets with little tiny differences in weight. Thus it's not unusual at all for me to have people saying stuff like this to me.

Like I don't understand the physics or the numbers. I try not to personalize it, but it's very hurtful. Bicycling does not happen under laboratory conditions, there are uphills, and wind, and **** like that, which mean that on any given 112 mile ride, you will be compelled to bring those wheels up to speed more than a few times. Were your statement true in the case of bicycle wheels, someone at R+D would be working on the steel, deep dish, aero rim even as I type this. They would be very fast downhill.

3alarmer 

...thanks, but it won't matter. It's late November, and obviously some people are bored.