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 :-

Hitting with Vokyl C10Pro 2012

Finally... I managed to hit with this highly recommended stick by Chris Edwards, one of the senior TennisWarehouse Play tester. Read his review here.  BTW, there were also quite a few supporters of Vokyl sticks on the Tennis Malaysia and Malaysia Tennis Lovers facebook groups.

Finally ordered and discovered that the Black Friday Sale of USD75.00 was no longer valid and the price increased to USD 159.99 and guess what, it was further increased to USD169.99 the very next day. Coincidentally, I was at the PSC and read in the May 2012 issue of the Tennis Magazine that the MRSP was actually UD 190.00 !

Received the stock on Monday and noted that the unstrung weight should be 330g and balance at 310mm. I took out my trusty digital weighing machine and was shocked that the unstrung weight was only 317g. Wow, a 13g difference... I had expected a +/- 1g difference as experienced with my Bio 100, 200L, 200 (2) and 300. Posted this at the TW forum

On receiving my Dunlop Black Widow 18g string, I had it strung yesterday and the final specs are :-
Strung Weight : 331g ( as compared to the advertised 346g)
Balance : 9.76pt HL (as compared to the advertised 8pt HL)

See TW forum post from another new owner

Posted a question to Chris Edwards on the TW Forum to seek advice on how to lead up to the advertised specs.

Started as usual with serves. Flat and Slice serves were nice and crisp but had some issues getting my kick serves to bounce higher than shoulder height. Managed to get my kick serve back but had to realy get under the ball :-)

BH volleys was very solid probably due to its high Twistweight of 14.16.

FH came with lots of spin and was able to easily hot with depth ie 1-2ft from baseline.

Backhand topspin was also easy to hot with depth and BH Slices was hit pretty crisp and low.

On the flip-side static overheads were not so crisp.

Working out with Nikesh on 30th November 2012

After working out with Nikesh a few weeks ago where I finally got to split-step regularly, learning to put-away short balls and well as a down-the-line and backhand volley combination, I decided that it was time to finally to learn to move back efficiently while being lobbed by pushers :-)

We started off by warning up with FH and BH on a mini-tennis basis.

Subsequently, it was FH time and I was able to easily return Nikesh FH :-) but in the process, discovered that on a fast and deep ball, I was hugging myself on the return and not following through completely :-(

BH hitting was a revelation as Nikesh exposed the fact that I was returning more continental rather than Eastern BH. Need to consciously change grip :-( In addition, I was not stepping forward to utilise my legs and body weight and was basically arming the BH. Later I realised that I was not turning my shoulder enough ie 'shoulder under the chin' and when I did did, the topspin was more pronounced :-)

Next was the drive volley. I have a pretty effective overhead (that came with hitting 50 overhead a day) but there are many occasions where the ball is high but yet not high enough for an overhead. I had tried doing it but it was an unmitigated disaster. With Nikesh guidance, I was able to do it with emphasis on holding the stick high, step forward and follow through over the shoulder. Hmmm... the makings of a new weapon :-D

A couple of years ago, I was back peddling furiously to retrieve a lob and could not stop my backward momentum , fell down backwards and hit the back of my head :-( Fortunately, I was not badly injured.
Since then, I had a fear of moving back to try to return a drop. As I occassionaly serve and volley, being lobbed when at net is a common occurrance. Nikesh started testing my static overhead and was satisfied with it. He then asked me to hit a FH volley and then a BH volley followed by a lob. On hitting the BH volley down the line, I quickly drop-stepped and move diagonally by using cross-over steps. Guess what, I was able to make most of the overheads ! Another new weapon that is screaming to be tried out tomorrow at our weekend double matches :-)

Footnote, a relevant video by Jeff Salzenstein


 

Solo Practice Diary : 8th Nov 2012

Started warm up with the Prepping like a Pro videos Part I & Part II

Practiced with my customised Biomimetic 100 (customised to be somewhat similar specs like the Wilson BLX ProStaff 90 ) this morning :-
a) Strung Wt=363g
b) Balance=30.96 mm (10.5 pts HL)
c) Swing Wt= 341.1 g/cm2 was previously 327.3
d) 6g lead tape at 10 N 2 (as recommended by Chris Edwards of Tennis Warehouse), was previously 2.2g
e) 6g stuck underneath the butt cap
f) 15g stuff inside the butt trapdoor
g) Solinco overgrip (5g)
h) Dunlop damper (2g)

I had previously had 2.2g @ 10 N 2 but decided to make it 6g to make it play like the Bio 200 as the strung weight of the BIO 200 was 330 as compared to the Bio 200's 336.

Serves, topspin/slices/flat serves pretty crisp using the same alignment to the net post. Concentrated on finding the ball well. Drop smashes also satisfactory and concentrated on OW tip about catching the ball before smashing.

Loaded up the Tennis Cube machine and practiced about 360 balls. FH OK but slices and topspin backhands not so satisfactory :-(

Also drop hit near the service line to simulate short balls and used windshield wiper to get it over but not long.