Twu swing weight calculator

travlerajm

G.O.A.T.
When using the 2-pencil support method, it’s important that your setup is rigid. That is, don’t hang the racquet with pencils cantilevered far out beyond the edge of the desk, or else the pencils/pens will deflect and absorb energy with each swing. I hang the racquet with only a mm or 2 between the pivoting frame and the edge of the desk, and use a heavy weight with a rigid base to lock down my bic pens.
 

junbun

New User
@Irvin
ok that's interesting.. My best readings with the app is usually right before the swings are too small for it to register.

@travlerajm
I hang mine about 1 - 2 CM out. I tried it a few times closer to my desk but noticed they were hitting it sometimes.. maybe my desk is much ticker than the one your using. BTW what is your hang distance for the ultra tour?
 
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taylor15

Professional
@Irvin
ok that's interesting.. My best readings with the app is usually right before the swings are too small for it to register.

@travlerajm
I hang mine about 1 - 2 CM out. I tried it a few times closer to my desk but noticed they were hitting it sometimes.. maybe my desk is much ticker than the one your using. BTW what is your hang distance for the ultra tour?
I just measured my ultra tour and ultra pro 18m. I knew they would be different due to the difference in static weight. Since I purchased one used and one new I didn't measure the unstrung weight before adding modifying. Both have leather and 2.5g tungsten at 12. I'm going to cut the string out of both after I play tonight, try and get the weight/balance matched unstrung and then have them strung with a matching string job. I'll measure again afterwards. I'm glad they don't match b/c I had the opportunity to test them both out and I really play better with the higher swing weight racquet. I'm going to try and get them both around 335 or so.
Here are my current measurements:
Swing TimeUltra Pro v3.0Ultra Tour v2.0
1​
13.73​
13.76​
2​
13.85​
13.83​
3​
13.77​
13.58​
4​
13.8​
13.81​
Average
13.7875​
13.745​
Balance
12.6875​
12.75​
Weight
340​
335​
Hang Distance
25.3125​
25.3125​
Swingweight
333​
328​
StringWilson Duo FeelKirshbaum Evolution 17g
ModsLeather Grip, 2.5g at 12Leather Grip, 2.5g at 12
 
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junbun

New User
Looks like we have the same hang distance
Which one do you like more ?

Heres a swing graph


@Irvin
By best i mean, the timing error from the app is lowest usually .002 seconds.
 

Irvin

Talk Tennis Guru
By best i mean, the timing error from the app is lowest usually .002 seconds.
When you say app do you mean RacquetTune? When you say .002 sec do you mean +/- 0.002 sec? Where on the racket is you pivot? I used to hang the racket from a cross string and the best I could get was +/- 0.002 sec. Now that I pivot the racket from 10 cm from butt I can often get +/- 0.001 if I keep the initial displacement down.
 

taylor15

Professional
Looks like we have the same hang distance
Which one do you like more ?

Heres a swing graph


@Irvin
By best i mean, the timing error from the app is lowest usually .002 seconds.
If you're asking me, I prefer the UP v3 more. The extra heft and also the hybrid strings suit my game more.
 

junbun

New User
When you say app do you mean RacquetTune? When you say .002 sec do you mean +/- 0.002 sec? Where on the racket is you pivot? I used to hang the racket from a cross string and the best I could get was +/- 0.002 sec. Now that I pivot the racket from 10 cm from butt I can often get +/- 0.001 if I keep the initial displacement down.
I'm using the swing timer app from the same person that made racquettune. I hang mine from the top cross. Can you take a picture of your setup? i've been thinking what's the best way to mount the racquet on the handle instead of cross strings. Mostly because i haven't found a good way to get twist rate measurements that i'm confident in.
 

junbun

New User
Hahaha i was watching this video a week ago ! Do you hang a piece of tape for the app to register swings for Twist rate ? it bugs me that i have to add a tape but i guess it doesn't affect the readings too much.
 
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taylor15

Professional
Due to a homesick child I won't be able to play tonight (driving to inlaws to get her). I'm going to cut the strings and drop both racquets off at my stringer tomorrow. I'm going to document the unstrung weight, additional changes and balance again after stringing. I have it lined up to take both to an RDC the week after thanksgiving to have them measured again. I'm interested to see how close it is.
 

Tregix

Rookie
My racquet is Blade 104 v7 with length 27.5 inches.
Will the TWU formula still work or is it only for 27 inch racquets?
Yes it does work for any racquet length.

(because you give the hang point and the center of mass measured from the end of the handle and these are the parameters needed together with the mass to apply twice the parallel axis theorem in order to compute the SW).
 
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