Based on YONEX swing index and my own experience, I finally got an equation to calculate the control and the power of a real stringed and gripped racket: C=W*W*B*GHP*S/100000000 where: W=weight(g) (together with added string and grip) B=balance point(mm) (the balance point measured from the end of the handle side) GHP=539(mm)for normal length racket, 549(mm)for long length racket S=stiffness (based on YONEX 2001 specification) range from 10(softest) to 20 (hardest) (http://www.asahi-net.or.jp/~zt8s-oon/bad-yougu.htm ) The reason weight is calculated twice here is because weight of the racket not only affect the swing difficulty but also affect the handling of the racket in defence. The result is very accurate based on my feeling of my own rackets at hand: TISSR C=22.6 (W=92, B=304, GHP=549, S=16) TISSS C=25.1 (W=95, B=298, GHP=549, S=17) 2U ISO100 C=27.8 (W=105, B=275, GHP=539, S=17) 3U MP100 C=30 (W=100CB=288, GHP=549, S=19) Larger C results in more smash power but less maneuverability, smaller C results in less smash power but more maneuverability. For me the ideal C value is around 25, the racket has a C of 25 can give me very powerful smash while still keep my defence ability high. Anything less than 23 will give more control but I have to swing unecessary fast to have enough smash power. Anything above 27 is out of the range of my strength thus can only be used when I'm in the top condition. Others may find their ideal values though.
great effort. is GHP measured from the grip end to middle of the racquet and you're assumption is thats where the sweet spot is? i guess the gauge/type of your gut; the tension used and the grip size (including the overwrap that you use) might have something to do with control and power as well
The CB of a 2U (without strings and grip )MP-100 is 274.5, W=94, GHP=549, s=19 But with string ang grip W should be about 105 instead. Mathematically, this formula has no chance really. It has no scientific/methodical basis. The issues of swing velocity, string tension, gauge, repulsion have not been looked at. The issues of aerodynamics have not either. And it effects the racket very significantly actually ! But nonethelss, a greateffort. Take it apart and look at it more closely, its not there yet even by a long shot.
I think you have the balance points recorded incorrectly for the above racquets. The heavier the racquet's head, the closer to the frame the balance point will be, thus measuring longer from the base of the handle. The way you have the racquets listed, you have the TiSP SR listed with a longer balance point at 304mm than the SS model, which is more head heavy.
that is right, since SR is lighter, the more weight are put on the head in order to make it still agressive.
I've never heard anyone else on this forum contending that the SR models of any Yonex Swing Power racquet was a head heavy racquet - maybe you have it confused with the SX models?
I think the the SR model is an agressive racquet for people who use more wrist or deceiving shots. The balance point is actually correct, mine measured around 310mm. It is strung with BG66 and is still using stock grip since I have no time to buy overgrip.
