I think your getting some misinformation.

A bow shoots to it's utmost effeciencey when at or near peak draw weight. A 80 lb bow shoots better at 80 lbs than it does set at 60 lbs.


Arrow flex should only be correlated to it's spine for each draw weight. An 80 lb bow shoots a different arrow spine than a 60 lb bow and the flex should be relatively the same as the 80 lb bow arrow is stiffer than the 60.