Okay @Nate7-5 , you obviously didn't read what I actually wrote. It probably doesn't really matter that the frame is 3 mm shorter as far as playability and feel- you just assumed I was upping the tension to deal with the distortion, and I outlined two other reasons why I was doing so (to mitigate the larger loss of tension on the poly creating a higher launch angle and to try out a string tension differential I have used in the past but not yet tried on this frame so that I could determine which string setup does feel and play best for me).Yonex has been making frames since the 1940s. You think they just released a brand new frame and didn't consider that people string mains and crosses and minor or significantly different tensions? Why TF does it matter if the frame is 3mm shorter after stringing - I doubt it affects the playability of the frame. I have no idea why someone would bother measuring. Have fun man.
Why would someone bother measuring a racquet? Well, in my case, I had strung a frame recently and my posts became loose, and the racquet distorted much more significantly. So when I strung the yonex frame, I measured to be sure my posts had not slipped again and discovered the 3 mm shortening. When I strung my second yonex frame at equal mains and cross tensions, I measured as a curiosity to see if the equal tensioning made a difference. In general, it's best to avoid distortion in the final stringing because you want to avoid placing uneven stress levels on the frame. Obviously, frame manufacturers design frames to be able to handle these stresses but that hardly means it is ideal. Furthermore, another reason for trying to limit distortion is that I have read that a 1 mm distortion is the equivalent of about 2 lbs of tension. Thus, it makes it harder to get consistent stringing results when the frame distorts too much or little in one direction when completed. I'm not sure how accurate that statement is on the tension effect, but this was my reference from where I read that somewhere else, "The relation between strain and stress is: σ = ε*E Assume a 300 mm long string with diameter of 1.25 mm and a Young modulus (E) of 5 000 N/mm^2. Since stress is tension over cross section area and strain is relative elongation, the tension change in 1 mm elongation is:
T = π*0.62^2*5000*1/300 = 20 N (or 2 kg)")
I thought these seemed like good reasons, but I probably am being ridiculous