Measuring Swingweight

What is Swingweight and why is it important measure of a tennis racquet performance ?

As per Tennis Warehouse University (TWU)

Much of a tennis hit can be seen as a battle between the player and the ball to move the racquet in a circle. Swingweight is the resistance to movement in a circle. Circular motion (as in most stages of a tennis swing) occurs around a center or rotation, let's say the butt end of the handle. When you apply equal forces to the handles of two racquets with different swingweights, the racquet with the higher swingweight will accelerate less and rotate less quickly around the center of the circle. The lower swingweight racquet will accelerate more quickly. In other words, higher swingweight means less maneuverability, and lower swingweight means more.

But the ball applies a force to the racquet also. And the same principle applies. The lower the swingweight, the more easily the the ball will move the racquet, and the higher the swingweight, the less easily the ball will change the motion of the racquet.

So the tradeoff becomes this: lower swingweight results in greater racquet acceleration and final swing speed, but more shock (due both to more racquet deceleration by the ball and higher impact force due to greater speed). Higher swingweight results in slower racquet acceleration and final swing speed but less shock due to less deceleration due to the ball pushing the racquet in an opposite circular rotation.
Power is influenced also. With a lower swingweight, the power must be generated more from swing speed. With a higher swingweight, more of the power comes from the racquet itself.

The Vokyl C10Pro 2012 which I received a week ago arrived minus 13g off its stated unstrung weight of 330g ie weighing in at 317g.



Strung with Black Widow 18g @ 60lb(actual : 50lbs), the strung weight was only 331g as compared with the stated average of 346g by TW. With the 3g Vokyl damper, the weight as shown on my digital weighing machine is 334g.

I added 13g at 6.75inch above the butt cap and plus the 3g Vokyl Damper, the strung weight is now 346g.
The stated average SW as per TW is 323g (comparison tool shows 331g), I really wondered what is exactly the SW of the leaded up stick which had been playing well (except for kick serves and overheads).

So I tried the SW measurement method as on  http://twu.tennis-warehouse.com/learning_center/swingweight_calc.php  and the results are as follows :

I took the average of 4 readings (13.88,13.93,13.83,13.85) and plug it into the SW calculation tool and the SW = 335g/cm2 which is much higher than the TW average SW of 323. The final specs are as follows :-