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travlerajm
07-23-2011, 12:01 PM
After some further analysis of pro racquet specs data, here is a new very interesting (and very statistically significant) result showing that ATP Pros with racquet MgR/I value in the apparent optimum range (20.6-21.2) tend to have better rankings.

http://s1.postimage.org/gx1qb684/Slide1.jpg (http://postimage.org/image/gx1qb684/)
Notes:
1. This dataset is for all of the Top-50 players with mass, balance, and swingweight data posted on Greg Raven's web site - 33 players are included in the analysis.
2. Only 2 players from Greg's site (Djokovic and Federer) were excluded from the analysis, due to large discrepancy between Greg Raven's data and TTW poster FabFed's apparently authentic measurements. If these players have swingweights within the the ranges of (352-366 for Djokovic) and (346-359 for Federer), they would be in the "optimized' group.
3. To adjust for wrist band use, a 0.2 'correction factor' has been added to the MgR/I value for all players found to be wearing wrist bands during matches in their peak years (or when the measurement was taken). The correction factor is needed to account for the extra mass of approximately 20g acting about 5cm beyond the wrist axis of rotation.
4. Kafelnikov's specs were assumed to be unstrung, and strung specs were estimated. Since he falls in the middle of the "optimized" group, error in the estimate of his stringbed weight will make no difference in the result of the analysis.
5. g was assumed to be equal to 980.5 cm/s^2
6. M = Racquet mass in kg
7. R = Distance from balance point to butt end in cm
8. I = Swingweight about butt end of racquet, converted from measured 10-cm axis swingweight (SW) using the parallel axis theorem, where I = SW + 20MR - 100M.

Players included:

<20.6 Group (n=14):
Chardy Clement Nadal Dent Arazi Gasquet Benneteau Tarango Moya Gicquel Murray Gambill Soderling Karlovic

20.6-21.2 ("Optimized" Group, n=12):
Pioline Ivanisevic Agassi Sampras Rafter Kafelnikov Davydenko Melzer Stepanek Kuerten Nalbandian Safin

>21.2 Group (n=7):
Krajicek Schalken Cahill Rusedski Ilie Lee Mirnyi

For 2 closely related threads, see:

travlerajm
07-23-2011, 12:22 PM
Data updated to include Soderling, Karlovic, and Mirnyi.

TennisMaverick
07-23-2011, 12:32 PM
After some further analysis of my pro racquet specs data, here is a new very interesting (and very statistically significant) result showing that ATP Pros with racquet MgR/I value in the apparent optimum range tend to have better rankings.

http://s4.postimage.org/18aohym04/Slide1.jpg (http://postimage.org/image/18aohym04/)
Notes:
1. This dataset is for all of the Top-50 players with mass, balance, and swingweight data posted on Greg Raven's web site - 30 players are included in the analysis.
2. Only 2 players from Greg's site (Djokovic and Federer) were excluded from the analysis, due to large discrepancy between Greg Raven's data and TTW poster FabFed's apparently authentic measurements. If these players have swingweights within the the ranges of (352-366 for Djokovic) and (346-359 for Federer), they would be in the "optimized' group.
3. To adjust for wrist band use, a 0.2 'correction factor' has been added to the MgR/I value for all players found to be wearing wrist bands during matches in their peak years (or when the measurement was taken). The correction factor size was determined to be 0.2 based on the effect of wearing a wrist band on optimum MgR/I value when tuning my own racquets against a wall.
4. Kafelnikov's specs were assumed to be unstrung, and strung specs were estimated. Since he falls in the middle of the "optimized" group, error in the estimate of his stringbed weight will make no difference in the result of the analysis.
5. g was assumed to be equal to 980.5 cm/s^2
6. M = Racquet mass in kg
7. R = Distance from balance point to butt end in cm
8. I = Swingweight about butt end of racquet, converted from measured 10-cm axis swingweight (SW) using the parallel axis theorem, where I = SW + 20MR - 100M.

Players included:

<20.6 Group:
Chardy Clement Nadal Dent Arazi Gasquet Benneteau Tarango Moya Gicquel Murray Gambill

20.6-21.2 ("Optimized" Group):
Pioline Ivanisevic Agassi Sampras Rafter Kafelnikov Davydenko Melzer Stepanek Kuerten Nalbandian Safin

>21.2 Group:
Krajicek Schalken Cahill Rusedski Ilie Lee

I commend your work, but since you have so many retired players on your list, before almost every player started using poly in their frames, how does the info relate to current technique and player physicality?

travlerajm
07-23-2011, 12:53 PM
I commend your work, but since you have so many retired players on your list, before almost every player started using poly in their frames, how does the info relate to current technique and player physicality?

I do not think the players of today are much different in physicality than the players of 10 years ago. Evolution takes longer than that.

And I don't think that string type matter much.

However, swingpath matters. For example, Nadal uses an steep uppercut forehand compared to most players. I suspect that this is why his forehand is so good with a racquet that has a low MgR/I value.

Marcus
07-23-2011, 01:01 PM
This is really interesting.....

However..... What impact does wearing a wristband make ? I'm unsure of the reference made.

Thanks
Mark

TennisMaverick
07-23-2011, 01:10 PM
I do not think the players of today are much different in physicality than the players of 10 years ago. Evolution takes longer than that.

The technique has radically changed from ITF through Futures to the Tour over the past two years, not mention the past five. The kids are training more like athletes, and the POV of coaches has changed. The game has become radically less traditional every year since around 2006. You're mistaking evolution in training and playing for that of the human being. With that being said, the average player's height and stature has also increased and that is evident at every event. There are few players under 6'. If you don't factor these changes, technique, training, strings, overall player size, and playing philosophy which has occurred during these past few years, with stringing data specifically from these players, then as solid as your research may or may not be, it isn't relevant to any players that I deal with. Don't get me wrong, I'm not trashing your insight, I'm just looking to use your material with guys who are playing now, so it would be immensely helpful to see what current top players are using.

travlerajm
07-23-2011, 01:14 PM
This is really interesting.....

However..... What impact does wearing a wristband make ? I'm unsure of the reference made.

Thanks
Mark

A wrist band slows down the natural speed of the pendulum sweep of the arm. This means that the speed of the pendulum sweep of the racquet about the wrist axis must be slower in order to compensate.

The MgR/I value gives a measure of the natural speed of the pendulum sweep of the racquet.
Thus, it is expected that players who wear wrist bands will have a lower optimum MgR/I value.

travlerajm
07-23-2011, 01:26 PM
The technique has radically changed from ITF through Futures to the Tour over the past two years, not mention the past five. The kids are training more like athletes, and the POV of coaches has changed. The game has become radically less traditional every year since around 2006. You're mistaking evolution in training and playing for that of the human being. With that being said, the average player's height and stature has also increased and that is evident at every event. There are few players under 6'. If you don't factor these changes, technique, training, strings, overall player size, and playing philosophy which has occurred during these past few years, with stringing data specifically from these players, then as solid as your research may or may not be, it isn't relevant to any players that I deal with. Don't get me wrong, I'm not trashing your insight, I'm just looking to use your material with guys who are playing now, so it would be immensely helpful to see what current top players are using.

I was joking about the evolution. Note that I added comment above before you posted regarding swingpath.

But honestly, do you think that players like Safin, Rafter, Sampras, Kuerten, Ivanisevic, Pioline, and Kafelnikov do not have physical size or strokes relevant to today's players? With the exception of Rafter, they all have pretty good forehands to emulate. And all of these guys are 6' or taller. And I noted above that Djokovic and Federer will likely join the 'optimum' group when swingweight results become available.

Power Player
07-23-2011, 01:27 PM
So strings don't matter but a wristband does?

travlerajm
07-23-2011, 01:33 PM
So strings don't matter but a wristband does?

The weight of the stringbed matters to swing dynamics, and so does a wrist band. String type affects impact dynamics, but that's not that relavant to the topic at hand.

Don't twist it.

TennisMaverick
07-23-2011, 01:39 PM
I was joking about the evolution. Note that I added comment above before you posted regarding swingpath.

But honestly, do you think that players like Safin, Rafter, Sampras, Kuerten, Ivanisevic, Pioline, and Kafelnikov do not have physical size or strokes relevant to today's players? And I noted above that Djokovic and Federer will likely join the 'optimum' group when swingweight results become available.

It is pretty obvious at any event that their technique is not relevant, and except for Rafter--Safin was just big--those guys are substantially less muscular.

travlerajm
07-23-2011, 01:54 PM
It is pretty obvious at any event that their technique is not relevant, and except for Rafter--Safin was just big--those guys are substantially less muscular.

All 5 of the current top-5 are addressed here. And since Ferrer also looks like a safe bet to land in the 'optimized' group, that's the top 6.

So of the top 6 current players, 3 of them appear to be in the 'optimized' group (Djokovic, Federer, and Ferrer). These 3 guys are pretty skinny. The other 3 guys who are not in that group (Murray, Nadal, and Soderling) are more muscular, so maybe you are on to something?

topspin18
07-23-2011, 06:30 PM
i am so confused!

ART ART
07-24-2011, 04:11 PM
travlerajm: again nice to see you around here

But I have a question for you:

I have this setup(lead+silicone) in a Dunlop 300T:
- 353 grams
- 360 SW
- 33 mm BP
Wich give me:
MgR/I = 20,49
MR^2= 385

like you can see, my MR^2= 385 this is an optimal value. BUT my MgR/I = 20,49 -much lower than optimal value.

Best Regards

larry10s
07-25-2011, 03:56 AM
my racquet is 354 grams balance 31.2 cm sw 333
am i "optimal"???

vsbabolat
07-25-2011, 07:59 AM
So strings don't matter but a wristband does?

When I wear a wrist band I play completely different. Forget about when I have one one each wrist.

travlerajm
07-25-2011, 06:24 PM
travlerajm: again nice to see you around here

But I have a question for you:

I have this setup(lead+silicone) in a Dunlop 300T:
- 353 grams
- 360 SW
- 33 mm BP
Wich give me:
MgR/I = 20,49
MR^2= 385

like you can see, my MR^2= 385 this is an optimal value. BUT my MgR/I = 20,49 -much lower than optimal value.

Best Regards

ART ART,
It's my belief that the optimal MR^2 zone of ~385 arises due to circumstance, because those pros that have both high swingweight (>350) and optimized MgR/I value (~21.0) tend to have racquets with MR^2 of about 385.

There are many pros with high swingweight but suboptimal MgR/I value. And there are many pros with optimized MgR/I value but low (suboptimal) swingweight. In both cases, the MR^2 value tends be less than 380.

My opinion is that it is well worth it to tune your MgR/I value to your personal optimum for your body and your swing.

You have already accomplished Step 1: getting accurate measurements for a starting point.

Step 2 is to calculate how much weight should be placed on the handle to move the MgR/I value to ~21.0 (to get it close).

Step 3 is to make the modification.

Step 4 is to remeasure the specs and verify that you are close to 21.0.

Caution: You're not done yet, as the most important step still remains!

Step 5: Tuning the racquet on the court:

I recommend that you grab some extra lead tape and find a wall or racquetball court. You cannot tune the MgR/I value by hitting balls that you drop -- you need the balls to be coming at you with decent velocity in order to tune the angular velocity of your stroke, so a wall is perfect for that.

The key to tuning your forehand is to unlearn your developed habit of compensating for racquet misalignment at impact by applying force with the wrist. You need to learn how to swing the racquet fluidly with a completely relaxed wrist.

A good analogy is when you go to the optometrist for the first time in your life to get glasses for near-sightedness. All of your life, you've been squinting in order to see the world. But when the optometrist is measuring the proper corrective power your eyes, it's important that you stop squinting for the first time in your life and let your eyes relax. Otherwise, you'll still need to squint even after you get your glasses or contacts.

So the same applies to tuning the MgR/I value of your racquet. You can't tell whether your MgR/I value is tuned properly if your wrist is not fully relaxed.

If your MgR/I value is slightly lower than your optimum, when you swing with a completely relaxed wrist, the racquethead will lag behind the hand at the moment of impact, causing you to naturally push your shots wide right (assuming you are righthanded). You need to resist the temptation to compensate by applying force from the wrist. It's kind of like when golfer has a slice swing and is less accurate because he has to always compensate for it.

Conversely, if the MgR/I value is slightly above your optimum, then when you swing with a completely relaxed wrist, the racquethead will get ahead of the hand, and you will tend to pull your shots to the left. The temptation here might be to convert the extra angular velocity into more topspin, but again you need to resist.

When your MgR/I value is perfectly tuned, you can simply fling your arm at the ball with a relaxed wrist, and the racquet will naturally stay perpendicular to your target all of the way through the hitting zone. This means that slight timing errors do not get punished. And you will notice that your targeting accuracy when hitting against the wall improves dramatically.

When my MgR/I value is tuned, I can hit a ball within a 1x1 foot square target almost every time. But if my racquet is slightly off, I can't hit as accurately. Compensating for the mistuned angular velocity might allow me to consistently hit the ball within a 3x3-ft square target, but why settle for that? That difference in accuracy is often the difference between winning a match and losing.

If MgR/I is too low, you can add a little more lead to the top of the handle. If it's too high, you can either remove some lead from that spot or add a dab to the tip. Don't settle for almost! Keep adjusting until you get that "in the zone" feeling.

When you are tuning for the first time, you might find it helpful to keep going beyond where it feels good until it's obvious that you've gone too far. You need to learn the difference in feel between MgR/I too low and too high.

Following all of these steps takes a lot of care and patience, but the end result is worth it.

Power Player
07-26-2011, 05:57 AM
Ok, I am going to try this out because I have a light stick with a 330 SW. The balance is 9pts headlight. It seems optimal to at least try this whole thing out.

I am very bad with math formulas..but I am thinking I can weight up the tip of the racquet at 12 with 18-22 grams of lead and the racquet would still weigh around 12.7 ounces (currently is 11.9). That should yield a very high swingweight...I really am not sure though. I am the worst at math, and simple stuff like this even throws me off until I completely get it.

travlerajm
07-26-2011, 07:26 AM
Ok, I am going to try this out because I have a light stick with a 330 SW. The balance is 9pts headlight. It seems optimal to at least try this whole thing out.

I am very bad with math formulas..but I am thinking I can weight up the tip of the racquet at 12 with 18-22 grams of lead and the racquet would still weigh around 12.7 ounces (currently is 11.9). That should yield a very high swingweight...I really am not sure though. I am the worst at math, and simple stuff like this even throws me off until I completely get it.

Power Player,

A few things:
1. I don't recommend skipping Step 1 (it's a really good idea to get an accurate measurement of your swingweight before you start).

2. If your SW is 330, adding 18-22g at 12 would push your swingweight to ~400, requiring a static weight of 15 oz. to optimize MgR/I. I don't recommend this (it works sweet on volleys and groundstrokes, but serving with a racquet that heavy is tough).

3. If you want to optimize MgR/I without adding any mass to the tip, it would take roughly 30g added just above the top of the handle (about 8 inches from the butt). For you're situation, this might be the easiest way to start before you head to the court to try to tune the frame. But again, I recommend taking a full set of measurements after modding if possible before you attempt.

Best of luck!

Power Player
07-26-2011, 07:58 AM
Wow..interesting.

Well my goal was to bring the balance down to around 5 pts HL while bringing the SW up. So I figured lead at 12 would accomplish that. Taking into account that 18-22 grams of lead is way too much, I have decided upon 8 grams of lead at 12.

That would bring me into the swing weight 2 category and also keep the racquet at a very reasonable weight.

It would probably leave me at : 12.2, 354 SW, balance of 5 Pts.

ART ART
07-26-2011, 02:21 PM
travlerajm: thank's for all those ideas!

I will try it, and then I will let you know the results.

Cheers ;)

Power Player
07-26-2011, 06:12 PM
TJam, I never really doubted the Swingweight2 theory. I mean the proof is right there in pro's racquet stats. Did I doubt that mere mortals could use sticks with that type of SW and hit consistently? Yes I did. Am I skeptical on the wristbands and odd stringing theories? Yes..but whatever. There is no doubt to me that this SW theory of yours is real.

After 8 grams of lead at 12:

Final specs:
Lemgth : 27.5
Static Weight : 12.2
Balance :6 Pts HL
Swingweight (guessing from TW data, will have real # from RDC tomorrow) : 360

This setup seems rather similar to Andy Roddicks, if not almost exact.

It was night 1, but it seemed easier to use. Much less energy to hit heavy balls. Reverse forehands that I had to hit in defensive positions went deeper. Timing was fine. I tested that by simply hitting for the middle of the court from both sides and was never late. To be quite honest, I lift a lot of weights and now am wondering if the high SW simply just made tennis easier for me. I may have been overswinging before..the racquet is easier to control and swing in a clean path. It was very rare for me to get too aggressive and lose control of the swingpath as I used to do.

I really like this weight so far..it's not too heavy, but it puts an absolute beating on the ball compared to the stock weight. It felt incredibly soild in the upper hoop.

You definitely need the right racquet to pull this off...I think mine was perfectly setup for it...regardless, I was honestly scared about an hour in that I was going to break a string and have to go back to my other unmodded stick. It simply takes less energy to hit a bigger ball.

I think people put pros on a pedestal too much sometimes in terms of gear. Their gear many times makes tennis easier. The higher SW to me appears to do just that. We shall see, but my initial impressions have been incredibly favorable.

TaihtDuhShaat
07-26-2011, 06:45 PM
I'm happy you took the time to try this out. This is exactly what I was hoping for in starting that Djokovic thread. I wanted to spark interest in experimenting with SW2 and MgR/I by using Djokovic's recent success as an example.

The thing with SW2 is, it gets even better as time goes on. It forces the use of good mechanics on all shots, which is like having a personal tennis coach in the racquet.

Also, your MR^2 (M=static weight in kg, (R= balance in cm)^2) is now ~377. If you want to hit an even heavier ball, try and bring the MR^2 up to ~385 by:

1) Take a couple of strips from 12 and and add them to 10 and 2. Then add more lead to 12 until the depth of your shots feels like it does now
2) Counter balance by adding lead at the top of the handle (~7" from buttcap) in 1g increments until the racquet comes around on forehands more easily. This will bring your MR^2 up without increasing the SW. The racquet will only be a few grams heavier, but it will hit an even heavier ball, and the added mass at 10/2 will open the sweetspot even more.

Power Player
07-26-2011, 07:17 PM
Well I well try and mess with it a little more, but to be honest I really like this setup.

Another thing I notice is that the feel of the racquet has improved to feeling incredibly solid on impact. The wild thing is that it felt great before, but this is another level.

My forehand feels like it is coming around perfectly right now..like the racquet is doing it for me..so I don't want to mess with it too much.

I should say that I would also fall into the muscular range...so maybe this is why.

TaihtDuhShaat
07-26-2011, 09:18 PM
Travlerajm,

This is sort of on topic since it relates to MgR/I. I tweaked my weighting of my 26.9" 95" 65RA 18 x 20 to arrive close to your recommended specs of 380g, 31.75cm, 360sw.

I ended up at 379g, 31.9cm, 374sw w/ an effective grip distance of 26.7" (366 effective sw).

This feels very balanced and is timed very well with my W grip forehand since I added more hoop mass, and added mass from the butt to 7" until it felt tuned on a wall. The racquet has incredible bite, and really hits a heavy groundstroke that's embarrassingly overpowering.

I found this 374sw by going to courts at 360sw and kept adding mass at 12 until my serve was heaviest; then measured the sw with the TWU pendulum method.

My question is, why is the sw so high for my max. serve? I'm only 5'10 142 lbs. is it the choked up 26.7" grip with effective 366sw?

Also, MgR/I =20.5, but feels very balanced on all shots. Is there any way to improve upon this given the W grip? If I adjust the SW in the calculation for 366 MgR/I=20.8, but that is kind of fudging one of the numbers without changing the others like effective balance, etc.

thanks otherwise for the recommendation, since it has increased the stability, power, and spin immensely.

travlerajm
07-26-2011, 10:55 PM
Travlerajm,

This is sort of on topic since it relates to MgR/I. I tweaked my weighting of my 26.9" 95" 65RA 18 x 20 to arrive close to your recommended specs of 380g, 31.75cm, 360sw.

I ended up at 379g, 31.9cm, 374sw w/ an effective grip distance of 26.7" (366 effective sw).

This feels very balanced and is timed very well with my W grip forehand since I added more hoop mass, and added mass from the butt to 7" until it felt tuned on a wall. The racquet has incredible bite, and really hits a heavy groundstroke that's embarrassingly overpowering.

I found this 374sw by going to courts at 360sw and kept adding mass at 12 until my serve was heaviest; then measured the sw with the TWU pendulum method.

My question is, why is the sw so high for my max. serve? I'm only 5'10 142 lbs. is it the choked up 26.7" grip with effective 366sw?

Also, MgR/I =20.5, but feels very balanced on all shots. Is there any way to improve upon this given the W grip? If I adjust the SW in the calculation for 366 MgR/I=20.8, but that is kind of fudging one of the numbers without changing the others like effective balance, etc.

thanks otherwise for the recommendation, since it has increased the stability, power, and spin immensely.

To calculate MgR/I when using an unusual grip position, you can try substituting the new effective R as well as the effective SW about the butt end. So your effective MgR/I would be about 20.6. Since you use a full western grip, it's quite possible that 20.6 would work best for you. As long as you know what value works best for YOU, you can then use the number again to get your specs close to your optimum on other racquets, and then the fine-tuning process will be easier next time.

If you are really interested in knowing your MgR/I value, I recommend being extremely careful when measuring SW with TW pendulum method. When timing, use the top cross and keep the amplitude low (about an inch of swing in each direction or less). I like to time 30 or 40 swings at a time, and then repeat another 30 or 40 to make sure my timing was repeatable. If you do this, the method is very accurate - but if you try to time only 10 swings, it's tough to do better than +/- 4 swingweight units because there is systematic error from your reaction time.

There is nothing wrong with an effective swingweight of 366. In fact, for me I find that to be roughly optimum power level for serving with a 95" standard length frame (as you found out for yourself). A general rule of thumb - as the center of the stringbed gets closer to your hand, the optimum SW for serving will get lower. As you go longer, the optimum SW for serving gets higher.

Sounds like you're enjoying your frame - happy hitting!

travlerajm
07-26-2011, 11:09 PM
TJam, I never really doubted the Swingweight2 theory. I mean the proof is right there in pro's racquet stats. Did I doubt that mere mortals could use sticks with that type of SW and hit consistently? Yes I did. Am I skeptical on the wristbands and odd stringing theories? Yes..but whatever. There is no doubt to me that this SW theory of yours is real.

After 8 grams of lead at 12:

Final specs:
Lemgth : 27.5
Static Weight : 12.2
Balance :6 Pts HL
Swingweight (guessing from TW data, will have real # from RDC tomorrow) : 360

This setup seems rather similar to Andy Roddicks, if not almost exact.

It was night 1, but it seemed easier to use. Much less energy to hit heavy balls. Reverse forehands that I had to hit in defensive positions went deeper. Timing was fine. I tested that by simply hitting for the middle of the court from both sides and was never late. To be quite honest, I lift a lot of weights and now am wondering if the high SW simply just made tennis easier for me. I may have been overswinging before..the racquet is easier to control and swing in a clean path. It was very rare for me to get too aggressive and lose control of the swingpath as I used to do.

I really like this weight so far..it's not too heavy, but it puts an absolute beating on the ball compared to the stock weight. It felt incredibly soild in the upper hoop.

You definitely need the right racquet to pull this off...I think mine was perfectly setup for it...regardless, I was honestly scared about an hour in that I was going to break a string and have to go back to my other unmodded stick. It simply takes less energy to hit a bigger ball.

I think people put pros on a pedestal too much sometimes in terms of gear. Their gear many times makes tennis easier. The higher SW to me appears to do just that. We shall see, but my initial impressions have been incredibly favorable.

Glad to here your experimentation with higher swingweights has gotten off to an auspicious start!

Serveand...
07-27-2011, 12:38 PM
hey what about some specs for women?

ben123
08-05-2011, 12:47 PM
http://sports.yahoo.com/tennis/gallery#photoViewer=urn%3Anewsml%3Asports.yahoo%2C ap%3A20050301%3Aten%2Cphoto%2Cap-201108051118407175339%3A1

when i saw this i couldnt resist to post it here

seems like rafa doesnt care much about this formular (no wristbands but he wears them in all matches !!!1111)

stules
01-20-2012, 04:12 PM
Hi Trav
Informative read. Very practical as well. Thank you.

A couple of things.............

I find while experimenting, that using rubber bands just above the
grip to be an easy way to adjust the swing speed while optimizing.
after I have found the ideal, I weigh the pile of rubber bands, and then
use that weight of silicon in that place internally in the frame.

What are your thoughts on the compromise between the ideal MgR/I
on:
Forehand
one hand backhand
two hand backhand
serve
tall player (long arms)
short player (short arms)

I find that I need a lower value for my one hand back hand than my
forehand. Serve, I haven't nailed the sweet spot.

What are your thoughts?

travlerajm
01-20-2012, 05:05 PM
Hi Trav
Informative read. Very practical as well. Thank you.

A couple of things.............

I find while experimenting, that using rubber bands just above the
grip to be an easy way to adjust the swing speed while optimizing.
after I have found the ideal, I weigh the pile of rubber bands, and then
use that weight of silicon in that place internally in the frame.

What are your thoughts on the compromise between the ideal MgR/I
on:
Forehand
one hand backhand
two hand backhand
serve
tall player (long arms)
short player (short arms)

I find that I need a lower value for my one hand back hand than my
forehand. Serve, I haven't nailed the sweet spot.

What are your thoughts?

On the rubber band idea, I actually use that myself! The rubber bands that come at the top of the grip to secure the grip usually weigh about 2 grams.

When I first get to the wall (in my case I use an indoor racquetball court)to tune a racquet that I have just built, the first adjustment make after hitting a few balls is try sliding that rubber band up into the throat or down onto the grip. For fine tuning, moving the rubber band around is a bit quicker and less messy than adding or substracting lead tape.

If sliding the rubber band around doesn't lead to a perfectly tuned result, then I start messing with the lead tape. If the rubber band adjusting does lead to a tuned result, then I try to readjust the lead tape to re-create the same balance but with the rubber band back in its original spot.

On MgR/I for forehand vs 1hb, I have found that racquets tuned for my forehand seem to feel pretty nice too for 1hb. But I need to add a disclaimer that I only use a 1hb for slices and volleys, but not for drives. My 2hb is my stronger side, much better than my forehand.

Also, I have found that 1hbs seem to be easier in general with racquets having really high static weight (like the specs in my signature) - I think this is because a 1hb relies less on a pendulum motion from the wrist than a forehand, and seems to be a stroke that is more connected to the larger pendulum pivoting from the shoulder.

On tuning MgR/I simultaneously for both forehand and 2hb, this is quite easy to do because racquet pivots about a different axis for a 2hb than it does for a forehand. For a forehand, the pivot point is where the wrist joint is (which is roughly even with the end of the racquet). But for a 2hb, the pivot point is the wrist joint of the top hand (which is roughly 10cm up along the handle). To tune for my 2hb, I replace R with R - 10cm, and substitute the SW about the 10cm axis (as typically measured) for I. Using this new MgR/I (let's call it MgR'/I'), I find my 2hb is best tuned when MgR'/I' = ~22.5. MgR/I for my forehand can still be tuned to about ~21.0 simultaneously, so no compromise is needed.

On tuning a racquet for the serve, I recommend ignoring MgR/I. The most important number to keep track of on the serve is the swingweight. For every player-racquet combo, there will be an optimum swingweight that let's you serve fastest. The amount of mass on the handle will have relatively little effect on the speed of your serve. Also, the length of the racquet affects the optimum swingweight for the serve. A longer racquet will have a higher optimum swingweight than a shorter one. For me, I find that my optimum swingweight for serve is in the 360s for most regular size frames, but this number can vary depending on the length of the racquet I use. Since MgR/I can be tuned independently of the swingweight, there is no compromise necessary here either.

I recommend experimenting with varied amount of lead added to the upper half of the hoop of your racquet while keeping track of the height of the bounce against the back fence to compare serve speed (a radar gun is not necessary in my opinion). When you find the right swingweight that lets you serve the heaviest (hits highest on the back fence after bouncing in the service box), then you can go back to your spreadsheet and find specs that will give you your tuned MgR/I value at your serve-optimized swingweight.

stules
02-15-2012, 04:17 PM
hi Trav
Thanks for the indepth reply. Always interesting ideas to digest and experiment with.

I am 6'1" tall, and want to build a racquet to optimum specs, by theory only.
I am stuck on a few points.....

Lets use a SW of 360 to get the most from the serve

I like S&V so I choose a recoil weight of 180

MgR/I of 20.8 is pretty close for me. Above this I can't tell the difference.

MR^2 of 380 just because it is a statistical target.

I end up with

372 gm
360 SW
7.1 HL

It is fairly depolarised.
I will lead up one of my PT57A's to see how it goes. Seems to me, that I can't get away from a fairly hi static weight to achieve the other objectives. That is probably my personal mental hurdle of 360gm weight limit. I will reserve judgement until I try it.

03-04-2012, 08:33 PM
TJam, I never really doubted the Swingweight2 theory.

You definitely need the right racquet to pull this off...I think mine was perfectly setup for it...regardless, I was honestly scared about an hour in that I was going to break a string and have to go back to my other unmodded stick. It simply takes less energy to hit a bigger ball.

I think people put pros on a pedestal too much sometimes in terms of gear. Their gear many times makes tennis easier. The higher SW to me appears to do just that. We shall see, but my initial impressions have been incredibly favorable.

1st, what is the "swing weight 2 category/theory?"

2nd, are the pro's stats favoring a high swing weight because with the swing used to apply heavy topspin (of the pros), more force is used brushing up on the ball instead of through the ball (more like on flat shots)? since the racket is traveling more vertically on contact, then it needs more mass behind it to impart more horizontal force...?

Power Player
03-05-2012, 11:03 AM
Hey I got your email and figured I would update this thread.

I really loved the SW2 thing for 1 week and then I played a match and got crushed. I realized I simply hit with a faster swing and raising the SW too high slows me down and my timing is messed up. Even trying to get used to it, I realized I use a lot of spin to control my shots and with a SW too high, I lost that control.

I do stand by my observation that if you like to let the racquet do the work, this is a very nice setup.

Pros favor a higher SW I think because they are absorbing a ton of pace and heavier SW gives it right back.

It is very tough to use a high SW racquet on the club level unless you play a lot and have flatter strokes.

Im a heavy spin player and once I start going over 340 I have to just make sure Im playing a lot of tennis.

bc-05
03-05-2012, 12:28 PM
weird!! i was calculating both my mgr/i and mr^2 and ended up having results that weren't even close to the range..

my current set up is:
prestige classic 600 and leaded up in the hoop (from 9 to 12) 4 long strips.. and the same amount of lead on the handle..

- weight: 404 grams
- balance - 31.5cm
- swingweight - from TW method (385)

ive been using this kind of set up since i was in my teen years (16 yrs old).. what should i do to optimize my setting? thanks in advance tho

03-05-2012, 03:56 PM
Hey I got your email and figured I would update this thread.

I really loved the SW2 thing for 1 week and then I played a match and got crushed. I realized I simply hit with a faster swing and raising the SW too high slows me down and my timing is messed up. Even trying to get used to it, I realized I use a lot of spin to control my shots and with a SW too high, I lost that control.

I do stand by my observation that if you like to let the racquet do the work, this is a very nice setup.

Pros favor a higher SW I think because they are absorbing a ton of pace and heavier SW gives it right back.

It is very tough to use a high SW racquet on the club level unless you play a lot and have flatter strokes.

Im a heavy spin player and once I start going over 340 I have to just make sure Im playing a lot of tennis.

but what is SW2, and then also, what is SW1 and any SW number?

i see what you're saying about pro's and high SW, but when you say that a club player would prob have to have flatter strokes when having a SW over 350, is that bc a club player generally doesn't have the strength to still effectively brush up on the ball with a swing weight over 350?

it's all kinda confusing bc I have flatter strokes and my SW is prob between 326 and 321. I made all my racquets 360 grams and 8-9 points hl this summer, thinking I could then whip the racquet up more with my semi-western stroke, increasing my top spin potential. I may try to calculate MR^2 and MgR/I with a more head heavy balance and same mass, bc i'm not having great success getting both of them optimized with the set up I have now. I do love playing doubles, and head light and heavy rackets do seem to be the best way to go, so i just don't know...

Fuji
03-05-2012, 05:11 PM
Hey Trav, Could you mail me through my profile? I want to get something like this going, but I have no clue where to start and what to do!

Thanks!

-Fuji

travlerajm
03-05-2012, 06:09 PM
Hey Trav, Could you mail me through my profile? I want to get something like this going, but I have no clue where to start and what to do!

Thanks!

-Fuji

Probably best to post your specific questions here.

To get started, I'd recommend buying:

1. A digital scale that measures to 0-500g range in 0.1 gram increments, along with a 200g calibration weight to make sure it doesn't wander.

2. A metal yardstick or meter stick.

3. A reel or two of 1/4" lead tape.

Power Player
03-05-2012, 06:10 PM
Lambs there is a huge head on sw2 just google it and it should pull up.

The thing about all this stuff is that in order to use these racquets at a high level you need elite speed and tons of practice like the pros have. Most people set up late, don't prep on time and don't have the grooved strokes required to utilize racquets of this weight.

I just literally hit next to a collegiate match going on next to me. I took a hard look and the guy who won was wielding an APDC and had massive strokes. He had to no lead anywhere on the racquet and had an awesome game with huge groundstrokes. Would he be able to utilize a heavier stick? Probably. Did it matter? Not at all.

But have fun with it and see if it works. The first few days are pretty amazing. I just like a lot o spin and even Nadal and mighty fed seem to prefer a SW of around 345, which can do a lot of damage to the ball .

Fuji
03-05-2012, 06:29 PM
Probably best to post your specific questions here.

To get started, I'd recommend buying:

1. A digital scale that measures to 0-500g range in 0.1 gram increments, along with a 200g calibration weight to make sure it doesn't wander.

2. A metal yardstick or meter stick.

3. A reel or two of 1/4" lead tape.

I can for sure do that!

Now lets say I take my testing stick (K90) strung with plain synthetic, and specs of 27 inch length, 355g, and 31cm / 9 points head light. I'm 6'0 tall.

What would specs would be required to make this into an "optimal" racket for me? I know there is probably more to it then that, but I'm awfully confusing with all this stuff. (I'm horrible with math!)

-Fuji

floydcouncil
03-05-2012, 08:06 PM

Added 5 of these to the very top cross. 3 on the left/right outermost main and 2 at my regular vibrator position.

I'm hitting almost as good as Djoker!!!!!!!!!!!! I won 5 games off a future level player. (I'm a 3.5 BTW.)

Fuji
03-05-2012, 08:16 PM

Added 5 of these to the very top cross. 3 on the left/right outermost main and 2 at my regular vibrator position.

I'm hitting almost as good as Djoker!!!!!!!!!!!! I won 5 games off a future level player. (I'm a 3.5 BTW.)

I honestly can't tell if you are joking or not :lol:

-Fuji

travlerajm
03-05-2012, 10:40 PM
I can for sure do that!

Now lets say I take my testing stick (K90) strung with plain synthetic, and specs of 27 inch length, 355g, and 31cm / 9 points head light. I'm 6'0 tall.

What would specs would be required to make this into an "optimal" racket for me? I know there is probably more to it then that, but I'm awfully confusing with all this stuff. (I'm horrible with math!)

-Fuji
Are those the exact measurements of your racquet (and not just the specs from TW)?

Fuji
03-06-2012, 02:12 PM
Are those the exact measurements of your racquet (and not just the specs from TW)?

Those are the exact specs, (I had it matched to TW specs when I got it.)

-Fuji

travlerajm
03-06-2012, 05:17 PM
Those are the exact specs, (I had it matched to TW specs when I got it.)

-Fuji

Then your next step is to carefully and patiently measure the SW using the TW University Swingweight Calculator.

When I do it, I set up a fullscreen online stopwatch on the computer.
Some tips for accurate measurement:
1. make sure the butt of the racquet is swinging no more than 1" in either direction from the reference mark on the floor.
2. Start the timer with your count at zero (not one).
3. Time 20 oscillations, and repeat 2-3 times or more until you can time well enough get the same time within 0.03 seconds every time. Then average the times and divide by 2.

Also, even though you think you know your balance spec. I'd definitely advise measuring yourself to know within 0.05mm. Small errors in balance will throw off the swingweight calculation.

03-07-2012, 05:26 AM
I would really like to try to get my SW up to 350, and what I can do right now is take my 360 gram racquet and make it 5pts head light (from 9pts hl), getting MgR/I to be around 21 and MR^2 to be 385. if racquetTune is correct, the SW would be about 341. I have calculated MgR/I to be around 21 with a few other mass and balance values, but thats with plugging in 350 as SW so I just need to double check what the SW would be according to racquetTune.

While this would be neat to do, to get a racquet close to pro specs, I think the closer-to-even balance and higher SW (is a 20-30 point increase in SW a "big" change) of this new set up would give me all that power back which I was trying to get rid of this summer. That's why I was a little confused with Power Players statement that "it is very tough to use a high SW racquet on the club level unless you play a lot and have flatter strokes." If high SW= high power, wouldn't someone who supplies more horizontal power (swinging through the ball, not brushing up) want to reduce power of the racquet? and like I said before, since i love playing doubles, i think this means a lot (quote from tom-selleck, data from jura):

BRIAN MIKE 4 354 29.7 69.8 TECNIFIBRE NRG 2 1.24 23/24

BRIAN BOB 5 354 29.8 69.8 LUX / TF ALU POWER / NRG 2 1.25/1.24 24/25

WOODBRIDGE TODD 3 353 30.7 69.8 WILSON NATURAL 1.25 24/24

NESTOR DAVID 5 375 29.5 69.3 BAB / LUX VS Team thermogut/alu powerBB 1.25 26/26

all doubles specialists, all heavy, head-light racquets

Power Player
03-07-2012, 05:40 AM
How is what I said confusing? It takes more effort to hit with spin and that is compounded by a heavier raquet. Spin is generated with racquet head speed and a low to high swing, which is why if your racquet is too heavy you can tire yourself out hitting with spin.

Flatter hitting takes less racquet head speed since you are driving through the ball and letting "the racquet do the work".

The only way to see is to slap lead on your stick and try it for yourself, but I am having trouble seeing how what I said doesn't make sense.

03-07-2012, 06:22 AM
How is what I said confusing? It takes more effort to hit with spin and that is compounded by a heavier raquet. Spin is generated with racquet head speed and a low to high swing, which is why if your racquet is too heavy you can tire yourself out hitting with spin.

Flatter hitting takes less racquet head speed since you are driving through the ball and letting "the racquet do the work".

The only way to see is to slap lead on your stick and try it for yourself, but I am having trouble seeing how what I said doesn't make sense.

the only mental block i have is that as far as I know, increasing SW increases power, regardless of if your hitting flat or with spin.

I know that with the motion for heavy topspin, a heavier racket will make you tired faster, but it will also add depth to the strokes (since the swing path is more vertical, the more mass behind it will drive a shot farther back). Since a flat hitter generally does not need added depth on their strokes, I don't see the need for a SW over 350, especially if someone wants to decrease power. I mean, travlerajm's stats kinda show this imo because the top ranked pros had SW over 350, and the majority of top ranked pros have high topspin strokes. all of this is dependent on if high SW = high power.

I may be over thinking all of this, but my main concern is that I want to decrease power, and if I alter a racquet to something that optimizes MgR/I and MR^2, I see that a high SW almost always comes with it.

Power Player
03-07-2012, 06:26 AM
Rafa and Fed hit with the most spin on tour and have had their SWs in the 340s for a long time.

So I am not sure what you are getting at.

Just lead your stick up and go see. I mean it's going to be obvious . I am speaking from experience here. You are just thinking about it too much and are not using real world experience.

You need racquet head speed to generate spin and depth. You do not need as much racquet head speed to hit flatter.

If you are Djokovic, you are a god and can hit with a big SW and use bigtime spin.

Good luck with that on the club level.

travlerajm
03-07-2012, 06:42 AM
How is what I said confusing? It takes more effort to hit with spin and that is compounded by a heavier raquet. Spin is generated with racquet head speed and a low to high swing, which is why if your racquet is too heavy you can tire yourself out hitting with spin.

Flatter hitting takes less racquet head speed since you are driving through the ball and letting "the racquet do the work".

The only way to see is to slap lead on your stick and try it for yourself, but I am having trouble seeing how what I said doesn't make sense.

Power Player,
You have missed the point of this thread. A primary reason for optimizing MgR/I is so that you don't have to apply any force from the wrist to keep your racquetface directed toward the target as you swing through the hitting zone.

Since a racquet with perfectly tuned MgR/I value will naturally stay aimed toward your target through the hitting zone, your control will be much improved.

Also, since you don't have to apply any force from the wrist, you can relax your wrist while you swing. This means that you will exert less energy and be less tired. In other words, optimized MgR/I (with proper tuning procedure) allows you to play with a much higher swingweight racquet without tiring out.

03-07-2012, 06:47 AM
Just to clarify, I'm not trying to emulate pros, i'm just looking at their specs to get an idea of how they balance out all of these racquet characteristics. I have never been a player to get the latest racquet or copy what I see players do on TV

Like I said, I'm just concerned that making my racket 5pts hl with a SW of 341 (which optimizes MgR/I and MR^2) will essentially bring me to where I was before I switched to 9pts hl and SW of 321ish, giving me back the power I wanted to lose plus will making it harder to generate topspin with my motion. But yes, I know that I would need to try it out and that it's more than just hypothetical or theoretical thinking

Power Player
03-07-2012, 07:20 AM
Power Player,
You have missed the point of this thread. A primary reason for optimizing MgR/I is so that you don't have to apply any force from the wrist to keep your racquetface directed toward the target as you swing through the hitting zone.

Since a racquet with perfectly tuned MgR/I value will naturally stay aimed toward your target through the hitting zone, your control will be much improved.

Also, since you don't have to apply any force from the wrist, you can relax your wrist while you swing. This means that you will exert less energy and be less tired. In other words, optimized MgR/I (with proper tuning procedure) allows you to play with a much higher swingweight racquet without tiring out.

I get that and I tried it out enough to know it doesnt work for my game, especially on serve which seems to be forgotten when people mention all this stuff . I also watch some very great players using stock babolats that are destroying the ball and winning matches, so I fail to see why I need to go through all this trouble when I prefer lighter sticks.

I may get bored and revisit it one day, but I am not a pro tennis player, do not possess their elite speed and footwork to setup these heavy racquets for my strokes, and do not understand how a club 4.5 player can benefit from this when proper footwork and prep IMO is far more important to master than weighting up a racquet.

TimothyO
03-07-2012, 08:52 AM
Rafa and Fed hit with the most spin on tour and have had their SWs in the 340s for a long time.

So I am not sure what you are getting at.

Just lead your stick up and go see. I mean it's going to be obvious . I am speaking from experience here. You are just thinking about it too much and are not using real world experience.

You need racquet head speed to generate spin and depth. You do not need as much racquet head speed to hit flatter.

If you are Djokovic, you are a god and can hit with a big SW and use bigtime spin.

Good luck with that on the club level.

QFT!

Power Player is absolutely correct on this.

For a given frame I push my SW and weight as high as I can go while maintaining enough head speed for useful spin. Too light and it feels unstable. Too heavy in terms of SW and spin suffers.

travlerajm
03-07-2012, 08:01 PM
QFT!

Power Player is absolutely correct on this.

For a given frame I push my SW and weight as high as I can go while maintaining enough head speed for useful spin. Too light and it feels unstable. Too heavy in terms of SW and spin suffers.

Actually, you just haven't gone high enough in swingweight to get back in the high spin range. If you add lead to a racquet with swingweight at 320, the spin will decrease. Your racquet will naturally hit the flattest ball around 355-360 swingweight. But after a certain point, if you continue to add lead, the spin will start to increase again. When you get up to about 370, the really heavy spin is easy to generate (even without spin-friendly strings). Of course you need to countnerbalance properly to make it easier to get the racquet around.

arche3
03-08-2012, 04:01 AM
I have been adjusting my racket every week or so. moving small pieces of lead tape around. I have it where it works well all around right now.

I found my setup measures 20.9

specs are right now:
353.6 grams
8 points HL
336 SW

This was a few months of tinkering until I found this setup.
I am not sure if I did the calculations right to get 20.9

Automatix
03-08-2012, 04:12 AM
I think it would be great if there was one thread with all the equations for calculating this "stuff" or at least in the first post. Looking for the eqs is a bit frustrating.

03-08-2012, 06:27 AM
I have been adjusting my racket every week or so. moving small pieces of lead tape around. I have it where it works well all around right now.

I found my setup measures 20.9

specs are right now:
353.6 grams
8 points HL
336 SW

This was a few months of tinkering until I found this setup.
I am not sure if I did the calculations right to get 20.9

you are correct, your MgR = 11020.33, and your I = 525.39, so your MgR/I = 20.9755

TimothyO
03-08-2012, 07:21 AM
Actually, you just haven't gone high enough in swingweight to get back in the high spin range. If you add lead to a racquet with swingweight at 320, the spin will decrease. Your racquet will naturally hit the flattest ball around 355-360 swingweight. But after a certain point, if you continue to add lead, the spin will start to increase again. When you get up to about 370, the really heavy spin is easy to generate (even without spin-friendly strings). Of course you need to countnerbalance properly to make it easier to get the racquet around.

If I did the calculation correctly my current MgR/I is 21.01. And, more importantly, it's comfortable, my arm feels good, and I generate very effective spin (crushed an opponent last night who ended the match drenched in sweat and clearly frustrated...my kick and slice serves gave him fits, and my changing between various slices and topspin groundies confounded him...I even pulled off topspin lobs for winners, something I had not done in match play previously.)

I have had it heavier and generated even more spin but my arm wore out faster.

Are you saying I can boost the MgR/I to around 370, which would require a significantly more weight, and achieve not only more spin but also maintain arm health? That sounds very attractive and I've enjoyed your research immensely.

But if my spreadsheet is correct I'm already near the ideal of 20.9 and things feel good (I'm 6' tall if that matters too).

I love to tinker so maybe I'll play around with this tonight. 370 seems terribly heavy for my middle aged physique.

Power Player
03-08-2012, 07:28 AM
370 is mammothly heavy. Wait until you try and serve with it..lol.

TimothyO
03-08-2012, 08:45 AM
370 is mammothly heavy. Wait until you try and serve with it..lol.

Precisely my concern!

I have to little boys. Can't afford shoulder surgery! :)

03-08-2012, 04:33 PM
Are you saying I can boost the MgR/I to around 370

do you mean 370 for SW (not MgR/I)?

from travlerajm "Adding lead to your racquet generally adds power, and flattens out your ball. But as you continue to add lead, eventually you get to a point where adding more lead increases spin."

at what point does adding more lead increases spin, is it a universal figure (like once you hit 13oz or something) or does it depend on the racquet? If it depends on the racquet, is the only way to figure it out by testing?

03-09-2012, 05:09 AM
from travlerajm"For someone that uses a pro-style high backswing (racquet head elevated to head level), a typical value for SW2 is 365-375"

so is that universal figure I was asking about before lower than 365-375 then?

travlerajm
03-09-2012, 05:31 PM
do you mean 370 for SW (not MgR/I)?

from travlerajm "Adding lead to your racquet generally adds power, and flattens out your ball. But as you continue to add lead, eventually you get to a point where adding more lead increases spin."

at what point does adding more lead increases spin, is it a universal figure (like once you hit 13oz or something) or does it depend on the racquet? If it depends on the racquet, is the only way to figure it out by testing?

It depends on the weight and balance a bit. But if you start with a typical stock racquet with Sw around 325, then start adding weight to the hoop, you will notice that the added lead results in a flatter ball. But as you keep adding lead to the hoop, the eventually you reach a point where additional lead starts to add spin again. This point usually is around SW of 360.

TimothyO
03-09-2012, 05:59 PM
Well, both PP and Travel were correct.

Travel was correct that at a higher SW and optimized MgR/I you eventually get more easily accessible spin. I tried a couple of setups today north of 360g static weight. SW for one was about 352. The other was 365.

But even with an optimized frame the sheer mass caused huge problems for me on serve. Ground strokes were great fun. Serves were a struggle. And my shoulder hurt no matter how loose I tried to remain with full "kinetic chain" motion.

Travel...did your study only look at men? I'm very curious about WTA stats.

Power Player
03-09-2012, 06:05 PM
What level player did you play against? Even groundies can be very tough against better players because you won't have as much time to get ready..that was another issue I had.

Against pushers, the heavy SW setup is crushing though.

TaihtDuhShaat
03-09-2012, 06:16 PM
ip office tom, when I'm playing against a heavy hitter and I don't have a high swing weight I missed time the ball because I have to swing so hard

Power Player
03-09-2012, 06:21 PM
I don't..I just use their pace and hit out in front with topspin. Is easier this way for me. Everyone is different though.

TimothyO
03-09-2012, 06:45 PM
What level player did you play against? Even groundies can be very tough against better players because you won't have as much time to get ready..that was another issue I had.

Against pushers, the heavy SW setup is crushing though.

Much better than I am. You hit the nail on the head.

Heavy frame does better against heavy shots but you need to be experienced enough to prepare properly. I'm not close to that yet. At least a heavy fra,e lets you block back more easily but it's tought to win just doing that.

And a Heavy frame also lets you crush floaters, which is fun! :)

the test wasn't a total loss. I did end up boosting the weight at 12 a wee bit and significantly under my palm. Enjoyed the effect on serve and stability vs heavy shots.

Power Player
03-09-2012, 06:51 PM
I may revisit it when I get a third pure drive, but it changes your swing a lot..you go from a lot of racquet speed, to a lot less, and it is not easy.

I'm at 328 SW, 4pts hl balance and 320 grams..not sure what I'd have to do to try it, but the stick would at least remain somewhat light..maybe.

03-09-2012, 07:28 PM
im struggling to get MR^2 = 385 AND MgR/I = 21 with a SW of even just 350.

where I've come close is:
360g and 5pts hl = 385, 342SW and 21.319
362.874g and 5.427pts hl = 385, 342SW and 21.381
357.204g and 4.570pts hl = 385, 341SW and 21.296
(all SW values according to racquetTune)

and I'm having a hard time optimizing the forehand to 21 and the backhand to 22.5. I will prob not optimze one of my current racquets bc all eight are extremely close to 12.7oz and 8pts hl. but I would still love to figure out the perfect combination to optimize everything. and im going to try to find The Physics and Technology of Tennis at my library, or buy it if it's not there, i'm sure there's a lot of extra info in there that would be useful

falc02
03-09-2012, 09:10 PM
Hi Everyone,

Firstly I would like to thank Travlerajm for providing so much information on racquet customization.

Secondly Travlerajm I was wondering if you have created a step by step procedure for creating a polarized racquet? I have created myself a worksheet for a depolarized a racquet based on your previous posts that includes calculating addition weight needed and weight placement, it also calculates the MgR/I and MR^2 values as well as swingweight prediction (from your posts on your racquet setup).

However after customizing my racquet to a depolarized setup I found that it just was not as maneuverable (too heavy) as I would have liked, especially for serves. I like to played with spin and found this racquet not able to generate enough as I would have liked. I understand that depolarized racquets are not great spin producers.

My current customized racquet specs are as follows:
Static weight: 352g (12.42 oz)
Balance: 32.0cm (12.61 inch)
SW (10cm): 340 kg-cm^2
Effective SW (4cm): ~448 kg-cm^2
MgR/I: 20.88
MR^2: 360.90

I have another stock racquet that has the following specs (to modify into a polarized setup).
Static weight: 336g (11.85 oz)
Balance: 32.7cm (12.87 inch)
SW (10cm): 336 kg-cm^2
Effective SW (4cm): ~440 kg-cm^2
MgR/I: 20.53
MR^2: 352.97

I feel a racquet setup around 12-12.2 oz would be best.

Kind Regards,
FALC

travlerajm
03-09-2012, 10:03 PM
Much better than I am. You hit the nail on the head.

Heavy frame does better against heavy shots but you need to be experienced enough to prepare properly. I'm not close to that yet. At least a heavy fra,e lets you block back more easily but it's tought to win just doing that.

And a Heavy frame also lets you crush floaters, which is fun! :)

the test wasn't a total loss. I did end up boosting the weight at 12 a wee bit and significantly under my palm. Enjoyed the effect on serve and stability vs heavy shots.

Interesting what you say about the serve.

I've noticed something - maybe this applies?

When I let players who already have a huge serve try my Sampras style weighted frame, their already huge serves get even bigger.

However, when I let player who has the type of serve where most of the racquet speed is generated from the arm, without much forward leg thrust, hip lean, or body torque, they say that they can't generate enough racquet speed.

In other words, if your service power is generated from your legs and body, having a heavier frame will only add juice. But if you are arming your serve, the heavier frame probably won't work so well for you.

TimothyO
03-10-2012, 01:32 AM
I'm definitely not the arm-the-serve type. In fact, my back is even towards the net a bit to maximize core rotation. I think of it as rotating the core to spin the arm up into the ball (vertical forehand?) and the frame goes along for the ride.

Don't forget, even with a proper shoulder turn/cartwheel the mass of the frame still puts strain on the tendons, joints, and muscles by "pulling" them through centrifical force. The less muscle mass one has relative to frame mass and speed the more strain. In some ways, a better, faster core rotation and swing to contact with a loose arm, will put even more stress on connective tissues. The discomfort isn't from muscle strain due to their contracting against excessive mass...it's from the mass pulling hard on the joints, tendons, and muscles as the mass is swung. In other words, the body can't tell the difference between a heavier frame swinging at high speed pulling on joints vs some hooligan running up to you and pulling on your arm as hard as he can! :)

Power Player
03-10-2012, 02:41 PM
I'm willing to this one more shot and I'll tell you why.

My strokes are developed enough to where they are not an issue with me in a match. The issue is consistency and a tendency to overhit the ball and hit out way too much. I am working on hitting a lot more under control and I still get plenty of racquet speed.

I am the size of ferrer..5'8 165.. Muscular build. I use a 27.5 frame and hit a semi western grip with a 2 hander. Current specs are 320 grams, 328 SW, and I will remeasure my balance but it should be 4 pts. I have 3 grams of lead at 12 and that is it.

What do I need to do to try the "optimized" racquet? I will do it and use it in matchplay and report back if someone tells me how to mod the stick.

Power Player
03-10-2012, 08:07 PM
Just to add to this I tried the twu swingweight thing and I am not sure if it works for 27.5 sticks...here is my specs now with a little added lead.

Balance is 13.3 when measuring from balance point to buttcap.

Weight is 328.

Average swing time doing twu technique is 13 seconds.

03-10-2012, 09:15 PM
Just to add to this I tried the twu swingweight thing and I am not sure if it works for 27.5 sticks...here is my specs now with a little added lead.

Balance is 13.3 when measuring from balance point to buttcap.

Weight is 328.

Average swing time doing twu technique is 13 seconds.

you also need the distance from the handle to where you're hanging the racket, also make sure you're counting 10 swings rather than 9 if you think the number you're getting is a bit funny

Power Player
03-10-2012, 09:36 PM
you also need the distance from the handle to where you're hanging the racket, also make sure you're counting 10 swings rather than 9 if you think the number you're getting is a bit funny

Yes..thanks..forgot to mention that's 62 cm.

I did the swing count thing 3 times and the number was 13 about every time ..once it was 12.9.

falc02
03-11-2012, 03:55 AM
Hi Everyone,

I am just wondering if anyone can help me out with my post above.

Cheers,
FALC

gatorbait01
03-12-2012, 08:15 AM
I think there may be some truth to the whole sw2 theory. I took my dunlop 4d 500 tour rackets and added 10 grams 12o'clock to the hoop and 10 grams inside the but cap.

Holy cow. I think you can get more spin with a higher swing weight. The weight on the hoop comes through the ball like a freight train. Once that tip gets moving it doesn't stop. Literally crushes through the ball.

Spin serves were great as well. I took an unmodifed wilson npro open to compare and it hits a much lighter ball.

In the past I have added lead to 3 and 9 and spin production has lessened causing me to lose consistency. At 12 it feels much different.

PP, you may want to give this setup a go. If you swing just 80-90% of maximum you will get 100 percent of your unmodified rackets.

One caveat, I haven't played a match yet. I've just hit with it. I do think it will work for me in a match because I could still dig out low slices inside the court with a buggy whip type swing. When I was using pure drive roddick, i coldn't control those type of midcourt balls well with topspin. I would either hit the back fence or apply a "brushy" topspin shot that just sits up for the pass.

My shoulder does feel a little achy today which is also raising some concerns, but I'm going to give it a go for a while.

03-12-2012, 11:27 PM
Yes..thanks..forgot to mention that's 62 cm.

I did the swing count thing 3 times and the number was 13 about every time ..once it was 12.9.

that's weird, I don't think the length of the racket should matter, but the calculator gives a rather low swingweight of 313 when I entered your numbers. If you double check your measurements and get the same ones, a racket with a static weight of 328, balance of 13.3 and swingweight of 313 has a pretty high MgR/I value (I get like 21.6). However, small differences in the time for 10 swings actually makes a big difference in swingweight. I would suggest trying to time the racket for maybe 20 swings or even more if you're up for it and adjusting it back down to 10, because you want to be as accurate as possible here. I think - I don't actually have too much experience with this process. But if you enter in different times, 12.9 vs 13 => a difference in swingweight of 6, which is pretty substantial when it comes to adjusting MgR/I

cellofaan
03-13-2012, 01:59 AM
Yes..thanks..forgot to mention that's 62 cm.

I did the swing count thing 3 times and the number was 13 about every time ..once it was 12.9.

You may want to try measuring more swings, like shadowshifter suggested. Much of the inaccuracy of measuring these things is our timing with the stopwatch, which is minimized when you count more swings. Alternatively, you can film the swinging racquet and count frames on the computer.

Finally, what racquet are you using? The SW may actually be this low.

gatorbait01
03-14-2012, 11:25 AM
I think there may be some truth to the whole sw2 theory. I took my dunlop 4d 500 tour rackets and added 10 grams 12o'clock to the hoop and 10 grams inside the but cap.

Holy cow. I think you can get more spin with a higher swing weight. The weight on the hoop comes through the ball like a freight train. Once that tip gets moving it doesn't stop. Literally crushes through the ball.

Spin serves were great as well. I took an unmodifed wilson npro open to compare and it hits a much lighter ball.

In the past I have added lead to 3 and 9 and spin production has lessened causing me to lose consistency. At 12 it feels much different.

PP, you may want to give this setup a go. If you swing just 80-90% of maximum you will get 100 percent of your unmodified rackets.

One caveat, I haven't played a match yet. I've just hit with it. I do think it will work for me in a match because I could still dig out low slices inside the court with a buggy whip type swing. When I was using pure drive roddick, i coldn't control those type of midcourt balls well with topspin. I would either hit the back fence or apply a "brushy" topspin shot that just sits up for the pass.

My shoulder does feel a little achy today which is also raising some concerns, but I'm going to give it a go for a while.

OK, I stand corrected. A few days ago I got the urge to try and lead my rackets up in hopes that it would benefit my game and protect my arm. I posted that it felt spin production and serving were great. Well...they were in practice. I played a match and found what I have always found with lead. It does help with volleys and my 2 handed backhand, but to the detriment of my forehand...and it's with my forehand that I win matches. I really wish I could hit my forehand as well with a 12oz stick that I can with and 11oz one, but I cannot.

I confirmed this last night by taking all the lead off one of my Dunlops and leaving it on the other. I got my ball machine to just send balls to my forehand and compared.

I just cannot get the ball to "dance" with all the lead on there. Running around my backhand is much more difficult as well.

Anyways I should be done experimenting with lead and heavy rackets until the urge stikes again and hopefully that won't be for another year or so.

Also all the lead like that really gives the racket a horribly dead feeling. Much better to use lead to tweak and not turn say a pure drive into a roddick.

Power Player
03-14-2012, 11:40 AM
You may want to try measuring more swings, like shadowshifter suggested. Much of the inaccuracy of measuring these things is our timing with the stopwatch, which is minimized when you count more swings. Alternatively, you can film the swinging racquet and count frames on the computer.

Finally, what racquet are you using? The SW may actually be this low.

Its a pure drive +..the swingweight should be in the 320s..I am going to get it measured on an RDC.

Gator, I have the same experience..you hit a certain point with the lead and it just tough to execute consistently if you are a heavy spin hitter.

Fed Kennedy
03-14-2012, 12:01 PM
Whats interesting is that I find adding a ton of lead really changes the feel of the racquet versus getting a heavy racquet and just putting small amoints of lead. With a ton of lead the feel just gets way muted even if you bring it to the same spec.
Perhaps lead is just duller than graphite.
Heavy stick with minimal lead goes better for me but seems opposite of what pros do...at least the HEAD guys that start with those ultra light hairpins.
I think its because they always get the sweetspot, so the dullness doesnt really bother them? Or maybe at pro pace, dullness is a good thing.

mareli63
03-24-2012, 05:46 PM
Travlerjam,
Your theory about MgR/I values for top WTA players being 21.1, it is not true.
Looking at Ana Ivanovici, Serena and Venus Williams racquets specs from Greg Raven website, their MgR/I values are lower than 20. Don't tell me they are an exception. They are top players.

travlerajm
03-25-2012, 10:48 AM
Travlerjam,
Your theory about MgR/I values for top WTA players being 21.1, it is not true.
Looking at Ana Ivanovici, Serena and Venus Williams racquets specs from Greg Raven website, their MgR/I values are lower than 20. Don't tell me they are an exception. They are top players.

The average MgR/I for WTA players is close to 21.1 because the average height for WTA players is close to 5'7". Shorter players tend to have shorter arms that swing faster.

The 3 players you mention are all very tall, and all 3 (particularly the Williams sisters) have longer arms and legs in proportion to their height than men of the same height. Venus is about 6'2", but her spidery arms and legs are about the same length as the limbs of a typical 6'6" guy.

So it's not surprising that these players have lower MgR/I values than most WTA players.

mareli63
03-26-2012, 10:06 AM
The average MgR/I for WTA players is close to 21.1 because the average height for WTA players is close to 5'7". Shorter players tend to have shorter arms that swing faster.

The 3 players you mention are all very tall, and all 3 (particularly the Williams sisters) have longer arms and legs in proportion to their height than men of the same height. Venus is about 6'2", but her spidery arms and legs are about the same length as the limbs of a typical 6'6" guy.

So it's not surprising that these players have lower MgR/I values than most WTA players.

Ok let's consider my daughter. She is 5'7" but her arms are very long. Her wing span is longer than her height. Does this mean she is ok with MgR/I of 20.3?
I tried to add lead at 7.5" inch from the butt as you said to bring the MgR/I to 21 but the racquet becomes to stiff. She doesn't like it. What do you recommend?

Fuji
03-26-2012, 10:24 AM
Whats interesting is that I find adding a ton of lead really changes the feel of the racquet versus getting a heavy racquet and just putting small amoints of lead. With a ton of lead the feel just gets way muted even if you bring it to the same spec.
Perhaps lead is just duller than graphite.
Heavy stick with minimal lead goes better for me but seems opposite of what pros do...at least the HEAD guys that start with those ultra light hairpins.
I think its because they always get the sweetspot, so the dullness doesnt really bother them? Or maybe at pro pace, dullness is a good thing.

I have the same ideas as you do actually! I've noticed the more lead I have, the more muted the feel is, but it's more powerful. It's quite odd!

-Fuji

03-26-2012, 10:30 AM
Fuji, I just posted my results for finding SW. You, and travlerajm, should check it out. look for the thread
Racquet Optimization: My Pursuit, Progress, and Findings Thus Far

Fuji
03-26-2012, 10:30 AM
I'll check it out bud! :)

-Fuji

Love Anet
11-10-2012, 04:22 PM
I understand that there are two ideal settings that have been sighted, and I would like to try them, but I don't understand all the details of the formulas etc.

Can anyone tell me how much lead to use and where to achieve these results?

The current specs of the racket are as follows:

Static Weight=363g
Dist. from butt cap to balance point=31.8cm(27" racket)
Swingweight=335