Is there a science to building metal bike frames?

[uber]

To the OP, I am wondering why you are asking this question? Are you interested in a custom builder making a bike for you? Is your preference to have the confidence that a large company with a large budget for R and D will make you the best cutting edge bike?
Having a boutique or custom builder make a frame/bike is no doubt a leap of faith, but so is buying an expensive bike from anywhere. There is a reason why the Tarmac is so popular year after year as there are also reasons why Richard Sachs (and others) command the reputation they have. No doubt, it was not the elaborate paint schemes that had Pegoretti making frames for TdF winners. When enough people share a common opinion, relative value is realized.
If your heart is to get a custom steel or Ti bike, my recommendation is to find a builder who seems to make the kind of bike you like. My preference is to have the builder personally measure me. It is his (her) experience getting the fit perfect for me that I find the most value in.
I have three road bikes; two custom steel frames that were measured by the frame builder and one current aero carbon production bike. They are all great and all better than my abilities. The carbon aero bike might be a bit faster, but it does not feel (ride) like a steel bike. Follow your joy.

[bigbill]

In the early 90s, I was faster on 20mm tires, at least that was my perception. I have metal bikes, really nice ones. If I want to go fast, I put fast wheels on one because the motor is the same.

[Kirk007]

Originally Posted by uber

The carbon aero bike might be a bit faster, but it does not feel (ride) like a steel bike. Follow your joy.

This has been my (sample of one) experience. Every ride on my Pinarello Dogma is a little bit higher ave. speed than my rides on steel (Sachs, Spectrum) and Ti (Spectrum). And I've got enough data points to believe its not that I'm just on a better day when on the Dogma. That experience is now a rationalization for something like some new Bora 35s for my rim braked bikes so that its same/similar wheelset comparison - all in the name of science of course.

But the Dogma (and every other carbon bike I've ridden) is missing that "je ne sais quoi" that I love in the feel/ride of a great steel frame.

[Toeclips]

If you drop a steel bike off the roof at the same time you drop a carbon bike off the same roof
One would think the steel bike faster

[prototoast]

Originally Posted by Toeclips

If you drop a steel bike off the roof at the same time you drop a carbon bike off the same roof
One would think the steel bike faster

Front wheel down? How do you figure?

[Toeclips]

Well I had to get that out of me

I do own two Atlanta's and two club Specials
Respectively they each look the same but I know the ride of each is different.
The two Atlanta's are most similar but the clubs couldn't be more different one is smooth as glass while the other feels like a track bike

When I look at a bike I'm interested in, I look to the geometry, is it tight I know what to expect
I know what to expect if the frame is stretched out

I do believe modern bikes are far better in all respects but nothing takes me back to the history of bikes like a steel frame
FWIW

[jpang922]

Originally Posted by Toeclips

If you drop a steel bike off the roof at the same time you drop a carbon bike off the same roof
One would think the steel bike faster

Galileo would disagree: https://en.m.wikipedia.org/wiki/Gali...isa_experiment
#aeroiseverything

[Toeclips]

I didn't consider there maybe a flaw with my experiment
I may chase the club special once it leaves my hands

To prototoast, I'm dangling them from their waterbottles

[martl]

Originally Posted by joevers

If you don't believe riders who have ridden both, the engineers that designed the bike, and independently tested data, well I'm just not sure what to tell you.

I do believe the numbers (science) and the theory I got thaught at a (German) engineering college.

A bike is not a car. The rider is on the outside, not inside a box. A *bike* with improved 10% aerodynamic performance can be messed up completely by having the rider moving his head by 1 degree. Today's GdI best time was 1:15 on the stelvio. I've seen a 55 year old dentist do the same, 15 years ago. No, modern technology does not make a bike faster on the road.

[joevers]

Originally Posted by martl

I do believe the numbers (science) and the theory I got thaught at a (German) engineering college.

A bike is not a car. The rider is on the outside, not inside a box. A *bike* with improved 10% aerodynamic performance can be messed up completely by having the rider moving his head by 1 degree. Today's GdI best time was 1:15 on the stelvio. I've seen a 55 year old dentist do the same, 15 years ago. No, modern technology does not make a bike faster on the road.

There are people in the comments telling you that their carbon road bikes are measurably faster than their steel/titanium bikes in the comments and not a single person saying the opposite. Frame builders do not claim their bikes are faster or as fast are newer carbon bikes because they aren't. There are still plenty of reasons to buy a metal bike, but being faster is not one of them.

I've owned 12 steel bikes, 1 aluminum, and 1 carbon. I love my steel bikes, I've had 1" standard diameter track bikes, triple oversize welded road bikes. I've worked as a courier on, toured on, commuted on, and raced road, cross, and track on steel bikes. And I'm telling you, any modern carbon road race bike from any big brand is going to be considerably faster than any comparable bike I own.

Is it enough to make a difference in a final sprint? I don't know. Is it enough to PR segments? You bet. Uphill, downhill, with a headwind, tailwind, crosswind, on long straight aways, on twisty sections. Something like a Tarmac or Systemsix is going to be faster than any bike I've owned on the road all else being equal every single time.

I understand what you're saying and you're right that fit has more to do with aerodynamics than the bike frame itself. Clothing and helmets also have a huge amount. That just doesn't change the fact that advancements in non metal frames and components have made them measurably faster to the tune of dozens of watts. Going from a 7/11 era Merckx to the latest and greatest carbon Merckx raced in the tour is like having a constant tailwind.

I'm not saying you're not educated or that your experiences are wrong and I hope I don't come off as such, but I don't think there's one manufacturer, frame builder, or high level racer that will tell you modern bikes are not faster, I think that's your opinion based on how much you seem to like old metal bikes or dislike newer composite bikes or marketing, and I think it's easily disproven by all the information right at your fingertips.

[Gummee]

Originally Posted by jpang922

Galileo would disagree: https://en.m.wikipedia.org/wiki/Gali...isa_experiment
#aeroiseverything

https://www.youtube.com/embed/E43-CfukEgs

If you were wondering

M

edited to add: I've got a few steel bikes, a few carbon bikes, and one carbon aero bike. It's hardest to go fast on the Giordana TSX frame, but that's mostly wheels. The bike that felt faster was a copy of an R5Ca. Then I got the aero/hidden cables bike with the aero carbon wheels. Get that one up to speed and easiest to ride fast out of the bunch.

YMMV as with everything else

[Black Dog]

Originally Posted by Gummee

https://www.youtube.com/embed/E43-CfukEgs

If you were wondering

M

edited to add: I've got a few steel bikes, a few carbon bikes, and one carbon aero bike. It's hardest to go fast on the Giordana TSX frame, but that's mostly wheels. The bike that felt faster was a copy of an R5Ca. Then I got the aero/hidden cables bike with the aero carbon wheels. Get that one up to speed and easiest to ride fast out of the bunch.

YMMV as with everything else

You cant compare bikes with different wheels, tires, components etc; there is no way to know what it is that is producing any differences. For all the aero talk, rider position has more to do with wind resistance than what the rider is sitting on, by a large margin. Since we are talking about steel vs CF frames if you lined up to frame/fork combos, one steel and one CF and had everything else the same (wheels, components, rider position) all of this alleged difference in speed would not be very large. There would certainly be a reduction in drag with an aero frame but it would not be like VW beetle vs a 911. There is a lot of conflation and confusion between correlation and causation in this thread.

[joevers]

Originally Posted by Black Dog

You cant compare bikes with different wheels, tires, components etc; there is no way to know what it is that is producing any differences. For all the aero talk rider position has more to do with wind resistance than what the rider is sitting on, by a large margin. Since we are talking about steel vs CF frames if you lined up to frame/fork combos, one steel and one CF and had everything else the same (wheels, components, rider position) all of this alleged difference in speed would not be very large. There would certainly be a reduction in drag with an aero frame but it would not be like VW beetle vs a 911. There is a lot of conflation and confusion between correlation and causation in this thread.

You're right.

For a lot of these modern bikes though, they would consider the frame, fork, seatpost, stem, bars, and sometimes even the wheels as their frame design and sell them together as such. There's not much benefit to copying the design of metal round tubed bikes because they don't have the same constraints and characteristics. A lot of modern cockpits on Cervelo, Cannondale, Specialized etc. are absolutely one of the biggest design features of a bike, and they're really not designs that are possible with metal bikes.

I guess take that for what it's worth. You're right that it's not an apples to apples comparison, but that's kinda the point. Composite frames don't have the design constraints and as such can be modified quite far from the design of a normal steel bike. The S5 is an example of a bike that in no way is influenced by metal frame design and as such uses its own seatpost, stem, and bars so it's not directly comparable to something like a Richard Sachs which obviously does not have those things.

[charliedid]

Originally Posted by joevers

I understand why you're skeptical, and believe me I love everything about steel bikes. I race road, cross, and track on steel bikes, and have a stack of tubes and lugs in my basement I'm hoping to braze this winter but:

Modern carbon bikes are so ridiculously fast there isn't any comparison at all, and that's 100% due to engineers and wind tunnels. Riding something like a System Six, which consistently tests as the fastest road bike, is absolutely and instantly noticeable as faster. Even around a parking lot. It isn't even close, and you don't need to be going 40-50km/h to notice. There's so much to love about steel bikes but pretending that carbon bikes do not have a LOT of science and design to them is naive and incorrect.

I'm with you on this.

Efficient use of power IMO = Fast

We used to laugh about a customers Cannondale System Six that was 3 sizes too small but 5 times as fast when we would test ride it.

Incredible really.

[.RJ]

Originally Posted by Black Dog

all of this alleged difference in speed would not be very large.

What is 'not very large' ? Cycling is a sport where wins are down to millimeters in the bike throw, and segments can be snagged or lost with a few seconds. If the bike makes a difference there, its large enough to matter.