Originally Posted by
cyccommute
I think you are confusing large tube diameter aluminum bicycle frame stiffness vs small tube steel bicycle frame stiffness with the overall stiffness of the materials. If all diameters and thicknesses of the tubing is the same, the steel tubing will be stiffer. Given that a handlebar is a fixed diameter...whether in steel or aluminum...the steel handlebars are going to be stiffer than the aluminum ones by a factor of a little over 2.
It will also be around 3 times heavier.
It is likely the steel will be a little stiffer, but not certain.
ASs you said, it is different for frames where they compensate for the lower tensile strength of aluminum by using large diameter thin wall tubes, but most aluminum handlebars have considerably thicker walls than a good quality steel bar. THe thicker wall will increase stiffness as well as strength, although not as much as increasing the diameter by the same amount. I would guess the difference in flex between a good quality steel bar and a good quality aluminum bar will be pretty minimal... definitely less than the difference between a 32mm wide and a 35 mm wide tire.