Jan Heine claims a 12% increase in power for a more flexible steel bike compared to a less flexible one. He does not show his work or the data. He shows a chart and says his legs feel warm on one bike and they hurt on the other. He claims the power meters were calibrated, by whom? Where is the cert. IIRC, there was a BQ article or two on the Specialized Diverge and it climbed better than his flexy steel bike but I could be wrong, I threw out all my BQ magazines and ended the subscription at that point. He measures speed with a GPS device to make conclusions on comparative tests. Real scientifically.

I also do not recall any explanation why the Diverge climbed better than his steel bike. Also, Lael Wilcox rides a Diverge and I tend to look at what top riders like she use more than marketing pieces.

I'd like to see one other "study" making the claim that a 0.4 mm tubing steel bike flexy as a noodle makes 12% more power.

That is really the gist of this thread. If lateral stiffness at the BB and chainstays did not matter, all those Specialized, Trek, Cervelo engineers need to be fired.