Swing weight estimate

[johnmccabe]

I've been experimenting with 2019 Prince tour 100p and lost track. The original sw is probably 1-2 points below spec before customization. I added probably 2.5-3 gram at 12 o'clock. Another 2 grams total at 3 9 o'clock. 5-10g in the handle. Static weight strung with overgrip 341 g.

Can someone estimate the swing weight, please?

 

[Soundbyte]

Customization Worksheet Tool

A tennis racquet customization tool that allows the user to define the amounts and locations of lead weight to add to the racquet, and the tool then calculates the resulting weight, balance, swingweight, twistweight, plowthrough, and power.

twu.tennis-warehouse.com

 

[chrisbc]

I've been experimenting with 2019 Prince tour 100p and lost track. The original sw is probably 1-2 points below spec before customization. I added probably 2.5-3 gram at 12 o'clock. Another 2 grams total at 3 9 o'clock. 5-10g in the handle. Static weight strung with overgrip 341 g.

Can someone estimate the swing weight, please?

That's a lot of guessing...I'd estimate somewhere between 334 and 337

 

[Bartelby]

You've added around 12 swingweight points so 332-334, starting with 320 or minus 2, but maybe up to 337 could be right.

 

[GuilhermeG]

The original sw is probably 1-2 points below spec before customization.

How do you know that? Have you measured it or are you simply guessing?

It is possible to calculate the sw increase by using the info you provided, but if you don't have the original sw it is impossible to estimate the final sw.

 

[Hnefi]

I've been experimenting with 2019 Prince tour 100p and lost track. The original sw is probably 1-2 points below spec before customization. I added probably 2.5-3 gram at 12 o'clock. Another 2 grams total at 3 9 o'clock. 5-10g in the handle. Static weight strung with overgrip 341 g.

Can someone estimate the swing weight, please?

Instead of guessing, use the Swing Tool app and measure it.

 

[Irvin]

Instead of guessing, use the Swing Tool app and measure it.

The only way to determine inertia is to measure it in this situation. Too many assumptions and guesses at mass and locations to accurately determine the SW. for example, adding 2.5 to 3 g at 12. Is the racket 27” long, it should have been stretched or compressed during stringing. Was the mass placed inside the frame or under the bumper? etc…

 

[danoontje]

The only way to determine inertia is to measure it in this situation. Too many assumptions and guesses at mass and locations to accurately determine the SW. for example, adding 2.5 to 3 g at 12. Is the racket 27” long, it should have been stretched or compressed during stringing. Was the mass placed inside the frame or under the bumper? etc…

Does placing the lead under the bumper or inside the frame make a substantial difference? thx

 

[Irvin]

Does placing the lead under the bumper or inside the frame make a substantial difference? thx

No not substantially. Inertia is more dependent on the distance from the pivot than mass in this situation. If the mass is placed inside the frame then it’s about 57 cm from the 10 cm pivot for a 27” racket. If the mass is placed under the bumper it‘s about 57.5 cm.

I = mr^2

If two g is placed inside the frame SW is 0.002*57*57 = 6.498 kgcm^2

If two g is placed under the bumper SW is 0.002*57.5*57.5 = 6.6125^2

There is only a difference of 0.1145 kgcm^2, but everything makes a difference.

EDIT: But look at the 3 & 9 locations. How far from the 10 cm pivot are those locations? 42 - 46 cm maybe, or more? Adding two g at 3 and 9 could add (.002*42*42) 3.528 or (.002*46*46) 4.232 kgcm^2 a .704 difference. Too much guessing means you’re going to come up with uncertainty.

 

[Mischko]

1g at 12 = 3.33 sw points, so 3g at 12 = 10 sw added

1g at 3 or 9 = 2 sw points added

 

[TennisHound]

Too many assumptions OP.
First, completely measure Twistweight,
SW,
circumference of hoop with proper angles calculated, balance,
RA with beam flex location variances,
grommet weight apart from racquet,
location of racquet manufacturer,
shipping date and method (air or sea),
location of metal insert in grip (go to the nearest airport and ask to use the X-ray machine, then measure distance from center of racquet).
Use the complicated TW SW measurement tool
Brand of RDI machine used to estimate SW.

Only then could your SW be estimated or even be considered close to some sort of finality.

 

[johnmccabe]

Too many assumptions OP.
First, completely measure Twistweight,
SW,
circumference of hoop with proper angles calculated, balance,
RA with beam flex location variances,
grommet weight apart from racquet,
location of racquet manufacturer,
shipping date and method (air or sea),
location of metal insert in grip (go to the nearest airport and ask to use the X-ray machine, then measure distance from center of racquet).
Use the complicated TW SW measurement tool
Brand of RDI machine used to estimate SW.

Only then could your SW be estimated or even be considered close to some sort of finality.

 

[johnmccabe]

look... guys! all I'm trying to estimate is whether I'm ready for trying gravity pro and tfight iso 305. their sw range is roughly 334-338.

 

[johnmccabe]

How do you know that? Have you measured it or are you simply guessing?

It is possible to calculate the sw increase by using the info you provided, but if you don't have the original sw it is impossible to estimate the final sw.

I bought it with match service. don't remember the exact, but have a rough impression.

 

[Irvin]

I bought it with match service. don't remember the exact, but have a rough impression.

If you used the matching service they had to have measured the SW without string. Did you ever think about what the SW was after stringing? Different strings in your racket and the TW ‘average’ could be quite different.

 

[johnmccabe]

If you used the matching service they had to have measured the SW without string. Did you ever think about what the SW was after stringing? Different strings in your racket and the TW ‘average’ could be quite different.

I'm using tourna big hitter silver 7 tour 17g in main and msv hex 18g in cross

 

[Irvin]

I'm using tourna big hitter silver 7 tour 17g in main and msv hex 18g in cross

And what’s the string mass of that setup compared to the string mass in the average racket TW used? I assume you have no idea.

EDIT: You could assume the mass is 2 g lower than TW’s average and now you SW is much lower.

 

[johnmccabe]

And what’s the string mass of that setup compared to the string mass in the average racket TW used? I assume you have no idea.

EDIT: You could assume the mass is 2 g lower than TW’s average and now you SW is much lower.

I don't know how to translate string difference to SW. Can you give a very rough estimate the total SW? doesn't have to be precise. a range is all I'm looking for. Although I'll most likely use similar thin gauge strings if I switch to gravity pro or tfight iso 305.

 

[Irvin]

I don't know how to translate string difference to SW. Can you give a very rough estimate the total SW? doesn't have to be precise. a range is all I'm looking for. Although I'll most likely use similar thin gauge strings if I switch to gravity pro or tfight iso 305.

You will get a better idea of the actual SW by using the TW method of measuring SW hanging the racket on a cross string to measure the SW.

 

[chrisbc]

I don't know how to translate string difference to SW. Can you give a very rough estimate the total SW? doesn't have to be precise. a range is all I'm looking for. Although I'll most likely use similar thin gauge strings if I switch to gravity pro or tfight iso 305.

Having played with the sticks you mentioned and having given you a sw estimate range, I’d say it will feel similar to the gravity pro if you get one on spec and that’s a big if.