Hi all - looking at old frame tubing specs, I see that for a long time Reynolds tended to sell sets with .1mm thicker walls in the down tube than in the top and seat tubes. So, a typical classic 531 frame was TT 1" .8/.5/.8, DT 1 1/8" .9/.6/.9, ST 1 1/8" .8/.5. Columbus, on the other hand, was typically .9/.6/.9 all around. Current day it seems that everyone (including Reynolds) just uses the same wall thickness all around.

The effect is that the relative stiffness among the tubes is different in the classic Reynolds frame than in others. I can't find any discussion of this on the web in general or here, though it's possible I needed to use some different search terms. Anyone with some longer history know whether this has been discussed or studied? I've read a pretty exhausting (not necessarily exhaustive) amount on whether "stiffness matters". I'm more interested in the question of whether relative stiffness between the tubes of the main triangle might matter in a frame where some flex is anticipated. Do any builders use stiffness ratios between tubes to tune flex characteristics to the rider, riding style, and where additional gear may be carried?

Ted Durant
Milwaukee, WI USA