Colorado Concept vs. Large-Diameter Straight Tubes

[cachagua]

Looking at the brand-new CSI in another thread, and reading that it's an awesome ride (hardly a shock), I began to wonder how a bike like that -- a CSI, a CRL, or even a Colorado III -- compares to one built with the large-diameter, consistent cross-section tubes in wide use today -- a Hampsten for example, or one from any of the builders in the ad bar above.

Someone must have ridden both styles extensively, and could speak to the similarities and differences, and the relative merits of each?

[eddief]

i am thinking every quite decent bike is made with butted steel these days. Or maybe you are speaking of shape and bend rather than I.D.?

Looking at the brand-new CSI in another thread, and reading that it's an awesome ride (hardly a shock), I began to wonder how a bike like that -- a CSI, a CRL, or even a Colorado III -- compares to one built with the large-diameter, consistent cross-section tubes in wide use today -- a Hampsten for example, or one from any of the builders in the ad bar above.

Someone must have ridden both styles extensively, and could speak to the similarities and differences, and the relative merits of each?

[MadRocketSci]

he means how the colorado concept tubes are shaped like redwood tree trunks....wider at one end (the base for the tree) than the other. Called a "frustum" if i remember my high school analytic geometry days correctly :)

[cachagua]

Yes, constant outside diameter, I should have said.

And, yes, I'm hoping we can spotlight the differences between frames with the redwood-trunk tubes, and those made from the "straight" double-butted tubes that top-shelf steel has evolved into more recently.

[bikinchris]

You could build in the same ride without shaping the tubes with butting. Other people do already. I rode my own Serotta Ti bike side by side with a same sized other brand that I sold. They happened to be exactly the same size. Both bikes rode great and very smooth and had very similar stiffness. The Serotta had the famously shaped tubes and the other bike had tubes that were not shaped. what is inside the tube has a lot to do with it. Wall thickness and butting length is what I am trying to get at.

[bluesea]

I'd always thought the csi type tube sets had to do with the tube set selection way back when. Times have changed, and there are good high performance round tubes that supersede the need for all the swaging etc.

[soulspinner]

I'd always thought the csi type tube sets had to do with the tube set selection way back when. Times have changed, and there are good high performance round tubes that supersede the need for all the swaging etc.

This

[saab2000]

I have a Pacenti with large diameter straight tubes and have had a total of three Colorado III frames with the Colorado Concept tubes. It's hard to say which is nicer but they're both excellent. The differences could probably be chalked up to differences of different days.

The Pacenti has notably larger chainstays and seatstays than the CIIIs.

If I had to place a difference I'd say the Pacenti is a bit stiffer and ever so slightly more race worthy because of this. The CIIIs are very smooth riding bikes and very lively. I almost wonder if the liveliness is maybe due more to differences in front end geometry.

The Pacenti is also very smooth. It would be very tough to choose between them. I'm glad I don't have to do so.