I'm going to respectfully disagree with Tom on this one.
Slight differences in frame tube weight have a dramatic difference impact on the way a frame flexes - so slight changes can make the difference between a frame that has a wonderful lively feeling and one that feels dead. It all depends on the interaction of the rider and the frame - riders often can't tell if a frame is dead because the tubing is too light - or too heavy, but they know it is wrong. That is why some bikes (geometry is important too) have a "magic carpet" feel, and others seem off.
Now the actual weight of the frame has a trivial effect on performance - is all about the flex!
To confirm this years ago, I had three Waterford 2200 frames built in identical geometry but with different tube spec. The change in bike feel from a change in chainstay thickness was dramatic! To say there is no performance difference due to tube thickness variations is simply wrong in my opinion. I know there are those who claim otherwise, and it may be that some folks can't tell a difference, but a great many folks feel the differences readily and we are simply amazed that some claim not to feel it.
Furthermore, there are builders that do believe that a bit of extra weight in the tubes add durability with absolutely no penalty for performance. Such bikes when ridden by "the public", since they are often overbuilt, only add to the public's perception that Steel bikes are heavy and sluggish. These builders are creating bikes that are a blight on the reputation of modern steel bikes.
Now some riders really crave an increadibly rigid ride, and the extra weight is in fact optimal for them. But for so many others this is simply not the case. And if such riders try the "heavy" steel, they are drawn readily to Carbon and Titanium alternatives.
Mike Kone in Boulder CO
> Given that nearly all the light weight tubing for making bicycles weighs
\r?\n> relatively the same...a tiny variation doesn't seem to make much difference.
\r?\n> The frame itself would have only a very small weight difference from one to
\r?\n> another of these tubes, is my thought. Then realizing what a small portion
\r?\n> of the total weight of the bike is a function of frame weight, it is hard to
\r?\n> see how all this could translate to much difference in the real world.
\r?\n> Perhaps different tubing requires different construction techniques?
\r?\n> Possible, but doesn't seem to be a critical factor.7
\r?\n> When we discuss tire weight, the weight of pedals or rims my attention is
\r?\n> immediately drawn. I feel these things really make a difference in the
\r?\n> actual performance of the bike. The difference in the total weight between
\r?\n> different sets of high quality tubes seems rather inconsequential by
\r?\n> comparison.
\r?\n> I wonder what the frame builders on the list have to say about this? I know
\r?\n> some use a mix of tubing...they must have their reasons...
\r?\n> Tom Sanders
\r?\n> Lansing, Mi USA