I have a 4U at700, it's strung with BG65, and I can see the string starting to go. The problem is, I have another AT700 (3U) and it is strung with BG65 TI, and I still produce much more power with the 4U at700 with bg65 string. I have no idea what the Bg65 tension is, and I'm preparing to string it for the string's inevitible breakage, problem is, I don't know what tension it is. Any way to tell? And would I produce same results with brand new bg65?
Simply answer: no, there's no way to tell. If you've got a stringer whom you trust and who is willing to work w/ you, then start with a tension setting---middle of the recommended range is a good start---and see how you like it. If you can't seem to generate power, restring it looser. If you can't seem to control your shots, go tighter. Adjust in 10% increments/decrements (i.e., +/- 2 lbs.) at first, then in finer adjustments as necessary. FWIW, HTH.
Maybe it's not the string, maybe it's the racket weight. Maybe the 4U is ideal for you while the 3U is too heavy for you to move optimally. A test you can do is have both rackets re-strung at the same time at the same tension with the same string, then see what happens.
I guess it is just psychological.. that u felt 3U performed poorer compared to 4u... trying using same string and compared.. if u still felt the same.. then swap 3u for 4u then hehe...
Why is it always 3UG5, 4UG4? A lighter racket has a bigger grip and a heavier racket has a, smaller grip??
Ask an experience stringer to estimate it for you. I once asked a different stringer to estimate the tension on one of my racquets and he estimated it correctly at 24lbs. He's also a coach. He did it by hitting the racquet face on his palm. They're really good at it. After all it's their bread and milk.