Thanks Prof, great experiment with very intreguing results, much appreciated!
I'm trying to get my head around how these findings can be reconciled with the increased spin with no concomitant loss of control reported for sub-40 lbs tensions in the "Low, low tensions" thread.
You conclude in this paper:
"The lower tensions and perpendicular stiffness of many polyesters leads to longer dwell times and greater deflection. This keeps the ball on the racquet for a longer arc of the stroke, potentially creating "power" problems with the ball going deeper, wider and higher than desired. The decrease in perpendicular stiffness also contributes to the sensation that the strings get "mushy" or behave like a trampoline. A loss of control is the end result."
Following this line of reasoning, shouldn't we expect to see the same phenomena and resulting loss of control when stringing at very low tensions in the first place? I don't observe this in my own rackets.
2 x Dunlop 4D200 Tour, full bed BHBR16 @ 36-38 lbs, tailweighted to ~10 pts HL, 374g