Official Swingweight, Twistweight, Static Weight, Balance measurements of your frames - Data thread

Power Player

Talk Tennis Guru
So with a lot of us getting the SW1 machine ( https://www.briffidi.com/ )or with access to RDC, Prince, Head diagnostics machines and already owning balance boards and scales I thought I would make a thread for folks to share their measurements of their frames as a reference for those looking for these stats outside of relying on TW's website for guidance.

The criteria here is you must have measured these frames with a true swing weight machine (not the swing weight app) and getting the twist weight is a much appreciated step as well. It's super tough to get accurate Twistweight though, so for now I will just post swingweights. I will update when I feel like I am getting accurate twist weight measurements.

The format can be copied and go like this:

Racquet brand and model and year or version and grip (strung with which string, unstrung, with overgrip, stock grip, leather or replacement grip) | Static weight- , Swingweight -, Twistweight, Balance

So for example (not official specs, those are coming) :

Yonex VCore 95 2021 4 1/4 (with supergroup, strung with 1.25 Lux Element) | Static Weight - 329.2 , Swingweight - 323 , Twistweight - 13.4, Balance - 32.0

If you have modded your frames, that's ok, just share that in the parenthesis with the amount of lead.

Ideally we can get unstrung unmodified frames in here, but the more data the better, and not every has time to take the lead off a frame they have already been using.

My first entry will be the 2021 Vcore Pro 97 310. Hopefully later today. Feel free to share yours as long as you can meet the criteria. The more data, the better it will be for people to see frame variances and make buying decisions as well.
 
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taylor15

Professional
So with a lot of us getting the SW1 machine or with access to RDC, Prince, Head diagnostics machines and already owning balance boards and scales I thought I would make a thread for folks to share their measurements of their frames as a reference for those looking for these stats outside of relying on TW's website for guidance.

The criteria here is you must have measured these frames with a true swing weight machine (not the swing weight app) and getting the twist weight is a much appreciated step as well.

The format can be copied and go like this:

Racquet brand and model and year or version and grip (strung with which string, unstrung, with overgrip, stock grip, leather or replacement grip) | Static weight- , Swingweight -, Twistweight, Balance

So for example (not official specs, those are coming) :

Yonex VCore 95 2021 4 1/4 (with supergroup, strung with 1.25 Lux Element) | Static Weight - 329.2 , Swingweight - 323 , Twistweight - 13.4, Balance - 32.0

If you have modded your frames, that's ok, just share that in the parenthesis with the amount of lead.

Ideally we can get unstrung unmodified frames in here, but the more data the better, and not every has time to take the lead off a frame they have already been using.

My first entry will be the 2021 Vcore Pro 97 310. Hopefully later today. Feel free to share yours as long as you can meet the criteria. The more data, the better it will be for people to see frame variances and make buying decisions as well.
Awesome idea! Are you going to update the first post as the Grips etc thread has been done?
 

MattHeup

New User
I would love to see a compiled average specs of all the posters here, and then play with the most popular setup on tt...
 

taylor15

Professional
Because??
You’re hanging by the strings. Hard to do that sideways.

I should have clarified that part of my point. If you’re doing the manual method hangingby the handle, or utilizing the SwingTool with other devices as in the homemade swing machine thread than you absolutely can.
 

bfroxen

Rookie
Because??
With most manual methods, and even most machines, there's not enough precision to get a useful twistweight measurement.

When I used SwingTool, I rarely got better than ±0.002 sec. precision, but even at ±0.001 sec precision, that only gives a swingweight precision of around ±0.8 kg·cm² (typical racquet hanging at the butt). Subtracting swingweight from spinweight, you get precision of ±1.1 kg·cm² (root-sum-square) or ±1.6 kg·cm² (worst-case). For twistweights on the order of 14.0 kg·cm², those results aren't very useful.
 

BlueB

Legend
I'm typically happy around 330g, 320 SW, 6 HL. I never bother with TW. I seem to notice the weight distribution and prefer de-polarized.
 

Power Player

Talk Tennis Guru
Ok let me get this back on topic. I will edit this post once I get some missing specs but I thought I'd get the SWs in now

2021 Yonex Vcore 95 (strung with 1.25 Element, Supergrap OG, and 3 total grams at lead at 3 and 9) | 332 grams , Swingweight - 317, 6 pts HL
2021 Yonex VcorePro 97 310 (strung with 1.25 Tour Bite, Supergrap OG) | 335 grams , Swingweight - 321, 6 pts HL
2019 ProKennex Q+5 Pro "Doppio" #1 (Wilson Pro OG, strung with 1.25 element) - 327 grams Swingweight - 322 7 pts HL Twistweight - 13.66
Head ProTour 630 (Babolat Leather grip, strung with 1.25 Luxilon) - 327 grams Swingweight - 322 7 pts HL
2016 Prince Phantom 93 (Stock leather grip, strung with 1.25 Rs Lyon) - Swingweight - 332 Twistweight - 11.45
2021 Pro Kennex Q+5 X #1 - (Wilson Pro OG, Strung with 1.20 Tour Bite ) Swingweight -328
 
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tim-ay

Hall of Fame
Finally wrote everything down in one place:

Doppio 1: stock grip with Tourna OG, 1.23 BK - 325SW, 327static, 32 balance. Bought from TWE - no wonder its slim cut.
Doppio 2: stock grip with Tourna OG, 1.23 BK - 329SW, 329 static, 32 balance. TW is about 13.2. More weight at the head i guess.
Doppio 3: stock grip with Wilson Pro OG, 17 TS - 328SW, 328 static, 32 balance.
Top Banana: stock grip w Wilson Pro OG, 1.23 BK - 326SW, 329 static, 31.4 balance - it’s an XL. (TB#2 is currently loaned out, but will be back Wed).
7G 1 - TS 17 w/ Tourna OG, - 327SW, 333 static, 31.5 balance
7G2 - TS 17 w/ Tourna OG, - 325 SW, 334 static, 31.4 balance
Clash 98 - BK123 w/ Tourna OG - 321SW, 331 static , guess I didn’t measure balance this time…. But think its around 9pts HL, so maybe 31.5 or so. Had 2g @12, but took off for measurements. Pretty clear why now. Will go back on (but don’t hit it often).

Doppio - PK Q+5 Pro (2019)
TB - PK Q+5X Pro (2021)

I think I like the Doppio’s with some weight on the handle. Which makes sense given mine seem to be a little beefier, except for my slim cut. I’ll add weight again to Doppio #3 and verify my feelings over time and play the other two stock for awhile.
 
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Irvin

Talk Tennis Guru
Doppio 1: stock grip with Tourna OG, 1.23 BK - 325SW, 327static, 32 balance. Bought from TWE - no wonder its slim cut.
Doppio 2: stock grip with Tourna OG, 1.23 BK - 329SW, 329 static, 32 balance. TW is about 13.2. More weight at the head i guess.
Doppio 3: stock grip with Wilson Pro OG, 17 TS - 328SW, 328 static, 32 balance.
SW = RW + mr^2
SW = RW + 22*22*(.327 to .329) (all 3 balance points are the same)
That portion of SW resulting from mr^2 would only account for a 0.5 kgcm^2 difference in 1 g between the 3 rackets. So the RW for all 3 rackets would have to be different. Weight added either above or below the COM would increase RW.

Just like adding 5 g 10 cm above or below the 10 cm SW axis. Either would increase the SW by 0.005*10*10 or 0.5 points. but you would have a difference COM.
 

tim-ay

Hall of Fame
SW = RW + mr^2
SW = RW + 22*22*(.327 to .329) (all 3 balance points are the same)
That portion of SW resulting from mr^2 would only account for a 0.5 kgcm^2 difference in 1 g between the 3 rackets. So the RW for all 3 rackets would have to be different. Weight added either above or below the COM would increase RW.

Just like adding 5 g 10 cm above or below the 10 cm SW axis. Either would increase the SW by 0.005*10*10 or 0.5 points. but you would have a difference COM.
It’s interesting because they all play similarly for me, but I could definitely tell the one was different. What’s really surprising is that I would have guessed #2 was the light one for SW, but it is probably less more polarized and maybe that’s what I was feeling. Weight on the handle for all 3 made them play more solid but I can’t explain why.

Thanks for sharing the math, I’m going to have to hit them and then decide if any adjustments are needed. They play so closely, regardless of the numbers.
 
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Irvin

Talk Tennis Guru
It’s interesting because they all play similarly for me, but I could definitely tell the one was different. What’s really surprising is that I would have guessed #2 was the light one for SW, but it is probably less more polarized and maybe that’s what I was feeling. Weight on the handle for all 3 made them play more solid but I can’t explain why.

Thanks for sharing the math, I’m going to have to hit them and then decide if any adjustments are needed. They play so closely, regardless of the numbers.
I’ve heard it over and over that SW is ‘the’ most important spec when matching rackets. I do not believe it. Balance is 50% of SW. Balance (and weight) is more of what a person feels when the pick up a racket.

weight on the handle lowers the COM and you must like a 32 cm balance. But you said the racket with a 31.4 cm balance was ‘top banana.’ Maybe even more weight in the handle would make them feel better for you. You could lower the balance to 31.4 without increasing SW is you added weight at 10 cm from butt.
 

tim-ay

Hall of Fame
I’ve heard it over and over that SW is ‘the’ most important spec when matching rackets. I do not believe it. Balance is 50% of SW. Balance (and weight) is more of what a person feels when the pick up a racket.

weight on the handle lowers the COM and you must like a 32 cm balance. But you said the racket with a 31.4 cm balance was ‘top banana.’ Maybe even more weight in the handle would make them feel better for you. You could lower the balance to 31.4 without increasing SW is you added weight at 10 cm from butt.
Top banana is an XL though so hard to compare - it’s 27.5. Also, the name is a ‘holic thread nickname so not necessarily accurate. Ha. But the best 27.5 I’ve hit with along with the 7Gs.

I think you are right; SW is important but it’s really one metric , maybe not any more important on its own vs. static and balance. I think balance might be #1 also, especially for us one handers. But too low or two high SW throws us off too. I’m guessing my sweet spot is a bit larger than I thought- maybe 324 to 332 SW or so?

Edit - I definitely felt the SW on the clash 98 was too low so I added 2g @12 before I knew that number I posted(321 without the lead). Which means with lead it is close to 328. No wonder I like that.
 
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Irvin

Talk Tennis Guru
@tim-ay you said you would guess the balance was 9 pts HL But you did not measure. That’s around 31.4 cm. Maybe you like 31.4 cm balance.
 

tim-ay

Hall of Fame
@tim-ay you said you would guess the balance was 9 pts HL But you did not measure. That’s around 31.4 cm. Maybe you like 31.4 cm balance.
That was on the clash 98 and I had measured it previously before adding lead… before I knew the SW. it felt like it needed head weight so I put 2g at 12. That probably only put it at 31.5 balance but I don’t use that frame that often. The Doppios are my main frames.

edit. I’ll add back the 2g and measure it later tonight.
 

aaron_h27

Professional
I’ve heard it over and over that SW is ‘the’ most important spec when matching rackets. I do not believe it. Balance is 50% of SW. Balance (and weight) is more of what a person feels when the pick up a racket.

weight on the handle lowers the COM and you must like a 32 cm balance. But you said the racket with a 31.4 cm balance was ‘top banana.’ Maybe even more weight in the handle would make them feel better for you. You could lower the balance to 31.4 without increasing SW is you added weight at 10 cm from butt.
SW is not as important as they claim on these boards.

Twist weight & balance is much more important.
 

Power Player

Talk Tennis Guru
Swingweight is very important to me when matching the same frames. I played a year with 2 blades matched in sw, weight and balance and never knew the twistweights.

They played absolutely identical.

Some pro customizers stress that SW is the most important spec to focus on. So its not just on these boards.
 

tim-ay

Hall of Fame
I also think it is important. Maybe 1 - 3 points don’t matter so much if other things being very close, but there is a point where it becomes a problem. Depending on the frame of course.
 

aaron_h27

Professional
Swingweight is very important to me when matching the same frames. I played a year with 2 blades matched in sw, weight and balance and never knew the twistweights.

They played absolutely identical.

Some pro customizers stress that SW is the most important spec to focus on. So its not just on these boards.
I was referring to using SW as the main culprit of choosing a racket. All SW is not created equal, like you said Yonex plays better with lower SW, some rackets play better with high SW.
 

Power Player

Talk Tennis Guru
I was referring to using SW as the main culprit of choosing a racket. All SW is not created equal, like you said Yonex plays better with lower SW, some rackets play better with high SW.
Oh yeah for choosing a racquet I agree. Yonex figured something out there. So did ProKennex with some of their frames.
 

Irvin

Talk Tennis Guru
Swingweight is very important to me when matching the same frames. I played a year with 2 blades matched in sw, weight and balance and never knew the twistweights.

They played absolutely identical.

Some pro customizers stress that SW is the most important spec to focus on. So its not just on these boards.
I'm not saying SW is not important if you matching multiple rackets. But I would rather have weight and balance matched than just SW. If your the match SW, weight, and balance that is clearly the best.
 

aaron_h27

Professional
I'm not saying SW is not important if you matching multiple rackets. But I would rather have weight and balance matched than just SW. If your the match SW, weight, and balance that is clearly the best.
If weight and balance are matched how much variance can there be with SW?

I'm asking because a lot of people don't have access to SW machines, so how close could one get just matching the static weight and balance?
 

Irvin

Talk Tennis Guru
If weight and balance are matched how much variance can there be with SW?

I'm asking because a lot of people don't have access to SW machines, so how close could one get just matching the static weight and balance?
That’s a difficult question to answer. Let assume you have a tennis racket with even balance and you add 1 g of mass above and below the COM at 34.29 cm. At 1 cm your RW goes up (1*1*.002) 0.002 kgcm^2. At 10 cm the RW goes up (10*10*.002) 0.2 kgcm^2? At 20 cm the RW goes up (20*20*.002) 0.8 kgcm^2? And at 30 cm your RW goes up (30*30*.002) 1.8 kgcm^2. So you can see the inertia is not linear. The RW of a tennis racket ranges from 150 to 175 kgcm^2 so if you just use weight and balance to compute without knowing the RW you could be off a good deal.

SW = RW + weight times balance minus 10 cm squared.

If you don’t have a SW machine to measure SW forget about SW. Don’t use weight and balance to compute it It can’t be done accurately no matter what someone tells you.

If you have 2 similar rackets my guess is the RWs are close. Just match weight and balance and go play.

If you’re in the market for a great SW machine for $270 check out Briffidi.com

EDIT: Check out https://tt.tennis-warehouse.com/index.php?threads/manually-measuring-swingweight.706895/
 
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BlueB

Legend
SW is not as important as they claim on these boards.

Twist weight & balance is much more important.
I completely ignore the TW when tweaking my racquets.
I'd rather have the W out by 10g, than SW by 5, as long as the balance is in the ballpark.
 

BlueB

Legend

Irvin

Talk Tennis Guru
I find the manual method pretty consistent, when I do it accurately. No clue if it corresponds to machine measured SW, but I don't care. I just use it as a matching tool, for myself.
With the SW1 I can measure the SW of a racket in seconds and I think it is accurate to within +/- 1 kgcm^2 maybe better. With other methods you need to measure weight, balance, hang point, enter measurements in some calculator and hope you’re close to the correct SW. Better tools give you better results independent of weight and measurements pure and simple.

EDIT: The SW1 is more like a toy for me right now. I’ll take 3 consecutive leasurements of SW rotate the racket 180 degrees and do it again. Then measure TW the same way. Call me crazy but it’s fun to play around with.
 
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tim-ay

Hall of Fame
I find the manual method pretty consistent, when I do it accurately. No clue if it corresponds to machine measured SW, but I don't care. I just use it as a matching tool, for myself.
Everyone gets to make a value judgement on the toys they use. For 270 bucks, the SW1 is awesome for anyone who is a tennis geek and wants to know their SW accurately. I really don’t care that someone else doesn’t care. I’m sure there are plenty of discretionary purchases each of us has that fall into that category.

For anyone who does care, this is by far the coolest ‘machine’ developed for tennis rackets in a long time. Everything in stringing has been incremental and you pay more, you get more. Scales have come a long way thanks to cheap Amazon kitchen scales, so that’s been good, but weighing has always been easy.

For Swingweight, really there hasn’t been innovation until now. And in the case of the SW1, you pay a lot less and get a lot more. Very repeatable and so easy to use.
 

PrinceYonex

Rookie
Everyone gets to make a value judgement on the toys they use. For 270 bucks, the SW1 is awesome for anyone who is a tennis geek and wants to know their SW accurately. I really don’t care that someone else doesn’t care. I’m sure there are plenty of discretionary purchases each of us has that fall into that category.

For anyone who does care, this is by far the coolest ‘machine’ developed for tennis rackets in a long time. Everything in stringing has been incremental and you pay more, you get more. Scales have come a long way thanks to cheap Amazon kitchen scales, so that’s been good, but weighing has always been easy.

For Swingweight, really there hasn’t been innovation until now. And in the case of the SW1, you pay a lot less and get a lot more. Very repeatable and so easy to use.
Well said.
 

PrinceYonex

Rookie
With the SW1 I can measure the SW of a racket in seconds and I think it is accurate to within +/- 1 kgcm^2 maybe better. With other methods you need to measure weight, balance, hang point, enter measurements in some calculator and hope you’re close to the correct SW. Better tools give you better results independent of weight and measurements pure and simple.

EDIT: The SW1 is more like a toy for me right now. I’ll take 3 consecutive leasurements of SW rotate the racket 180 degrees and do it again. Then measure TW the same way. Call me crazy but it’s fun to play around with.
Do you get different swingweight readings when you rotate 180 degrees?
 

Irvin

Talk Tennis Guru
Couldn’t that just be within the normal variance of the SW measurement?
If the machine and racket are level, the butt cap is square, and the racket is mounted the same each time there should be no more variance whether the racket is re-mounted or not.
 

tim-ay

Hall of Fame
If the machine and racket are level, the butt cap is square, and the racket is mounted the same each time there should be no more variance whether the racket is re-mounted or not.
the first time i measured my PK Q+5 Pros i really recognized this. i don’t love the PK butt cap so I wrap my overgrip high- above the edge maybe a mm or two. when i serve, that little bit folds over the lip and feels better to me.

the little extra over grip also affected my mounting in the SW1 and i was getting readings 1-2 high. flipping the racket would get different readings also. once i figured it out, the error went away but i still get more variance from mounting than from the machine - very little though, maybe .1 -.2 like irvin says.
 

Irvin

Talk Tennis Guru
@tim-ay that’s understandable. If your racket weighs 330 g and your balance point is 32 cm, when converting RW to SW (SW = RW + mr^2,) the mass and distance from the COM to pivot (.330*22*22) adds 159.72 kgcm^2 to inertia. If you increase the distance by 1 mm the inertia goes up 1.5 points (.330*22.1*22.1.)
 

12oz

New User
For those that have a SW1, do you have to recalibrate it every time you use it. Say you store it away and then use it on a different bench or table. Do you have to adjust the legs every time? This is what is putting me off buying it.
 

Irvin

Talk Tennis Guru
For those that have a SW1, do you have to recalibrate it every time you use it. Say you store it away and then use it on a different bench or table. Do you have to adjust the legs every time? This is what is putting me off buying it.
If you move the SW1 from 1 level to another it should be leveled again if you want accurate readings. But if Your just measuring 1 racket whether the SW1 is level or not you SW would be accurate +/- 1 point. If you’re trying to match rackets both rackets will be off the same amounts if the SW1 is not level. So if they’re both off the same they will be matched and witching +/- 1 point.

look at it like a set of scales That are 1 g off. If I measure 2 different rackets and they are both the same even though they’re 1 gram they are the same.

if you had a monster SW machine like the RDC you would still have to level and calibrate it every time you moved it if you want it accurate. If you didn’t you readings would be off. Whether you measure 1, 2, or more rackets all or off the same.
 

12oz

New User
Thanks for the reply. All things being equal if you have left it in the same spot and use it on a level bench, then there should be no need. But if you take it out a few months later and can’t guarantee it hasn’t been moved - best to recalibrate.

I have 10 RF97s that are with +/- 1 SW, as measured by the local pro shop, but I have a feeling twist weights are all over the shop due to Wilson’s shoddy QC and weight distribution.
 

tim-ay

Hall of Fame
Thanks for the reply. All things being equal if you have left it in the same spot and use it on a level bench, then there should be no need. But if you take it out a few months later and can’t guarantee it hasn’t been moved - best to recalibrate.

I have 10 RF97s that are with +/- 1 SW, as measured by the local pro shop, but I have a feeling twist weights are all over the shop due to Wilson’s shoddy QC and weight distribution.
calibration is really fast, just another one of the benefits of the machine. You can store the machine away, bring it out, and be measuring with full confidence in just a couple of minutes.
 

Irvin

Talk Tennis Guru
IMO +/- 1 point is old school, you can do better. Your problem is if you start trying to adjust TW you’re going to have to start over again. Say you want to increase TW up 0.1 point, and 3&9 positions are 12 cm from centerline and 42 cm from the SW pivot. If you want to increase TW by 0.1 you must add 0.7 g to 3&9 positions. When you add 0.7 g to increase TW you add 1.2 points to SW.

Calibration is very easy. 2 measurements with the calibration rod + weight, 4 - weight, and 2 again with the weight. You can do that in about 1 minute. Then you switch to calibrate tab and press the calibrate button. Like Tim said about 2 minutes.
 

Irvin

Talk Tennis Guru
I doubt you could calibrate any other SW machine as fast as you can a SW1. Actually the SW1 does most of the work.
 
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