Originally Posted by
rpenmanparker
So now I will weigh in. I say no to the above question. Any historical observations about steel comfort weren't due to an advantage of steel, but rather to the particular way that steel was being used. Ti, Al, or CF if used the same way (i.e. designed for the same stiffness/compliance balance) would produce approximately the same results, albeit with different frame designs required to accommodate the particular physical characteristics of the particular materials.
My question would be, can you design aluminum frames to have the same physical characteristics of steel? The elephant in the room with Aluminum is always it's tendency towards failure from metal fatigue. The very thing that we laud steel for (it's flexibility) has to be avoided in aluminum because regular flexing of aluminum will lead to catastrophic failure (I know I have experienced it first hand and have the scars to prove it). This is historically why aluminum frames have been stiff. I know there's a lot of fancy shaping and forming that can be done to mitigate this issue, and certainly some of the more experienced Aluminum framebuilders (Cannondale) make frames that are comfortable "enough", but there's a limit to plushness that can be achieved, and I think steel frames can go farther in that direction.
At the end of the day, for me, I'm a guy who doesn't race, but rather rides for distance and prefers the looks of a modern steel frame to aluminum or carbon frames, so arguments over what the best frame material are mostly moot, I enjoy what I ride. I know that my aluminum bike is not as fun to ride on a century as my steel ride, but like most people on here, I only have a few data points. None of those data points have ever been carbon I'll add.