Secret to a Maximum Performance Racquet: A Tale of Two Swingweights

[travlerajm]

deleted by author.

 

[McStud]

wow. i am going to try this on a few of my racquets. will post back and let you know the results. thanks trav!

 

[ollinger]

Pseudoscience nonsense. We don't know that the first curve is parabolic (could be irregularly shaped, and it would be a different curve for different strokes, as one may not have equal strength on forehand and backhand sides) and we don't know that the optimum power line intersects at two points as you assume or one (tangential). Too many baseless assumptions.

 

[travlerajm]

Pseudoscience nonsense. We don't know that the first curve is parabolic (could be irregularly shaped, and it would be a different curve for different strokes, as one may not have equal strength on forehand and backhand sides) and we don't know that the optimum power line intersects at two points as you assume or one (tangential). Too many baseless assumptions.

I did NOT say that the curve was a parabola. I said it is roughly shaped like a parabola just to give people a better picture of its shape. Please do not twist my words.

Also, it is easy to prove that the line intersects at two points. If it is possible to make your racquet overpowered by adding lead to your hoop, then it proves this. Because what goes up must come back down.

 

[Noveson]

I was very interested in this, right up until I realized I didn't understand lead tape very well. Anyway travlerajm you are a genius Great to have you on this board.

 

[louis netman]

What happened to the "concentrated mass" setup? Or was that just the racket-setup "flavor of the month?" BTW, my C9 with double 4" strips at 3 & 9 and about 1oz of lead above the handle (ala concentrated mass) performs the best out of all my C series frames...Now I've got to put 1/4" lead al the way around the top half of the hoop....???

 

[anirut]

Hi Travler:

Interesting article. How can we plot the curve? Any formula?

Thanks to you guys for coming up with all this technicals. I never knew I'd play best at SW 326. I've only found a nice setup for my Redondo without knowing the SW. It wasn't only until the spreadsheet was distributed that I found the SW figure.

I do appreciate that many "technicians" here are making racket setup more "measurable" than just blindly adding weight and messing things up. I don't know if all the technicals are 100% correct, but they do serve as a very good basis for mods, a very good starting point.

"Great spirits have always encountered opposition from mediocre minds." - Einstein

Thanks Trav! Keep up the good work!

 

[travlerajm]

What happened to the "concentrated mass" setup? Or was that just the racket-setup "flavor of the month?"

A concentrated mass setup works fine, as long as you apply it so that find SW2 accurately. The method I provide in this thread (adding to the upper hoop) is simple and does a decent job of preserving the original feel of the racquet.

 

[Amone]

Another interesting thing to study, Travler? If there's a specific swingweight you should use, does that mean that polarization is not variable? I've done some of the math, and I've come to realise that polarization comes down to those three most important variables: weight, swingweight, and balance point. So if there's a specific layout of those things, does that mean that specific polarizations aren't good?

 

[travlerajm]

Another interesting thing to study, Travler? If there's a specific swingweight you should use, does that mean that polarization is not variable? I've done some of the math, and I've come to realise that polarization comes down to those three most important variables: weight, swingweight, and balance point. So if there's a specific layout of those things, does that mean that specific polarizations aren't good?

The rules for polarization are the same as always. Given the same swingweight, a more polarized frame will be less powerful. Lower power level shifts the curve downward. This shifts SW2 to a lower level, which is good. So polarization is generally a good thing.

The downside to a frame that has too much weight in the lower handle is that the shorter balance point decreases SGPR. So that is the limiting factor for polarization.

 

[bertrevert]

Can anyone clarify this equation SW1 = 325 kg-cm^2 am I missing something in this equation?

PS - "start at 12 o’clock" - you mean centred at 12 o’clock.

 

[stules]

PART 1: THE TWO PARADIGMS OF RACQUET DESIGN

If you have chosen a well balanced stock frame, adding mass to the handle will generally not be necessary, as most high-end tweeners and player’s frames are designed with handle mass that fits the stiffness well.

Hi Trav
several questions for clarification if I may.
1.
I am unsure of where this comes from (above quote). Adding 10 gm to the head would give me roughly 3points more head heavy than stock, only 'pro balance' would have me more head light for a higher mass.
So, am I to assume that this is for determining the SW2 only, and adding mass to the butt is a later concern to achieve 'pro balance?
2.
adding 10 gm to the upper rim of the racquet is only going to increase the SW by about 25 or so, bringing the SW to about 350ish from the std 325 that manufacturers have chosen to supply us with. what if this falls short of SW2, which I gather it may, wouldn't it be preferable to add, say 15gm, definitely overshoot SW2, and then reduce until the ideal is found? I just spent an hour testing my RDS001mid by starting above (I think above) SW2 at 357gm and SW of 370 with 18gm of lead going from 9, 10 11 etc through to 3. Damn it clobbers a heavy ball at high SW's...... I was taking it off in 2 gram increments, only I can't say I noticed power sweetspot on the way back to usual 338sw.
3.
For calculations, are your base figures based upon TW's or RSI's, as they differ enough for concern. Actual mass I measure, but SW's are different.

Is this correct? I am starting with an underpowered players frame. I add head mass to raise the SW. Then it starts to get too powerful on groundies, but I don't, as conventional wisdom would have it, reduce SW, but instead keep increasing head mass and hence SW until the power level returns to the prefered level. Thus I arrive at SW2, with its associated benefits.
Regards Stuart
PS do you sleep at night, or just lay awake thinking of this stuff? If you think of it I am happy to try it.

 

[louis netman]

Travlerajm: I just added lengthy strips of lead to the hoop of my C9 (from 4:00 to 8:00). I have only two overgrips and my usual butt expansion. On the Bab RDC, it measures the exact SW as my leathered, overgripped C10 Pro which is already SW2. Why don't I simply use the C10?

 

[Adk]

Hi Travlerajm,

Very interesting article.

To your experience, is there any stock racket you know are designed to have its SW at SW2?

Can I undestand the term "well-balanced' as "equally balanced"?

Thx a lot.

 

[Moves]

Awesome, Awesome post travlerajm! I can't wait to try it out!

- Moves

 

[Amone]

Hi Trav
several questions for clarification if I may.
1.
I am unsure of where this comes from (above quote). Adding 10 gm to the head would give me roughly 3points more head heavy than stock, only 'pro balance' would have me more head light for a higher mass.
So, am I to assume that this is for determining the SW2 only, and adding mass to the butt is a later concern to achieve 'pro balance?

Don't take this as gospel, but here's my 'crack' at replying to that one: He's not referring to the balance, but to the actual number of grams in the handle. You can move the balance all you like, but you do it with the head-weighting.

 

[travlerajm]

deleted by author.

 

[travlerajm]

double post

 

[Two Fister]

If the reason why power level comes back down at SW2 is because the racquet is now so heavy that you can't physically get as much racquet head acceleration (Force=MassXAcceleration type of thing), thereby decreasing power (or Force), is that a good thing?

I would expect that for a given player, their strokes and timing would have to change. Spin has a lot to do with with speed of the racquet head, so if you can't accelerate the head as fast, wouldn't your spin go down?

I would also expect that because we are kind of at a threshold of being able to swing the racquet, that the player will tire out much faster and would have more trouble in the third set.

TravelerJam, are you somehow connected with the ATP? You imply that all top 100 ATP players have this type of set up. Respectfully, how do you know that? Not trying to attack you, but just would like to know your qualifications, since you make such a bold statement. I do see that you have a PhD in biomechanical engineering which is impressive.

Thank you for your well thought out and thought provoking post.

 

[travlerajm]

deleted by author.

 

[LuckyR]

travlerajm,

Thanks for the follow up article. I say "follow up" because of it's general nature rather than the very specific "this setup" or "that set up" racquet reports you have written before. I am still sticking with my PK Ionic 5 with the "Safin" lead setup that plays flatter than your true Safin racquet. But last night I took a page out of this article (before reading it) and lopped off 3/4 inch of lead at the bootom of the hoop (string cross #4) on each side and added that 1 1/2 inches back at the butt. The feel is still solid but there is a lot more headspeed and perhaps more spin potential. I'll report back after this weekend on how it goes.

 

[Two Fister]

No, your spin will not go down. It will go up. The increase in spin efficiency of your racquet due to the added mass in the head will more than compensate for the lower swingspeed.

First of all, thank you for your thorough reply.

Still not sure about this "spin efficiency" concept. In my personal experience, it seems like the lighter, whippier racquets can generate tons of spin. I don't understand how increasing the swingweight and thereby lowering racquet head speed (heavy pendulum vs. light pendulum) will result in a faster rotation of the ball as it leaves the strings.

Maybe you misread? At SW2, you are not at the threshold for being able to swing a racquet. Rather, you are at the ideal swingweight.

Sorry, I shouldn't have said "threshold." But what I meant was that the only reason why the power level is coming back down from the maximum peak power level is because the operator is NOT CAPABLE of accelerating the racquet as much due to the increased weight. So the operator will be laboring more with each stroke, than if he were at SW1 achieving the same power. I see this as a disadvantage. But maybe the advantages that you listed would outweigh this disadvantage.

Interesting topic.

 

[FitzRoy]

Interesting thread, travlerajm. What about string pattern? Would having an 18x20 pattern vs. 16x19, 16x18, etc, have an impact on the curve?

 

[BlackJesus]

I didn't unterstand do I have to add a continuos 10gm lead tape cenetered at 12 or cut the lead and add at 12 3 and 9 in pieces of the same length? If someone has tried tis setup can post some pics of his racquet for bettere unterstand how to make it. Sorry but as I don not speak english as my first language sometimes It's difficult to me to unterstand properly the instruction to follow. Thanks

 

[brtennis]

I have the same reservations that two fister has in his post #22.

In addition, the power-sw curve will be different for each stroke. For ground stroke, the power source tends to come from truck rotation and the swing path is largely pararrel to the ground. For serve and overhead, however, the up swing path is working against gravity, thereby more sensitive to sw variation. I know for sure I will be quickly tired serving w/ sw2.

Just want to chime in some points to this interesting thread.

 

[AlpineCadet]

PART 1: THE TWO PARADIGMS OF RACQUET DESIGN

a racquet at SW2 will provide:

- More directional accuracy on volleys.
- More depth control on volleys.
- Better touch on drop shots.
- Better touch on lobs.
- Rebound velocity that is less dependent on incoming ball velocity.
- Rebound angle that is less dependent on incoming ball spin.
- More directional control on groundstrokes.
- More depth control on groundstrokes.
- Increased spin efficiency (heavier ball).
- More solid returns.
- More power on serves (higher SGPR).
- More spin on serves (heavier ball).
- A more fluid and consistent swingspeed (that depends more on the moment of inertia and less on muscular input).

So SW2 provides all of these advantages. The only disadvantage would be slightly decreased maneuverability. With all of these advantages to using SW2, it is clear why no current player can compete on the ATP tour using a racquet at SW1.

This is a joke, right? You contradict yourself a few times in your list. I don't understand why all your posts are written this way. What's your agenda behind all this?

 

[LuckyR]

I didn't unterstand do I have to add a continuos 10gm lead tape cenetered at 12 or cut the lead and add at 12 3 and 9 in pieces of the same length? If someone has tried tis setup can post some pics of his racquet for bettere unterstand how to make it. Sorry but as I don not speak english as my first language sometimes It's difficult to me to unterstand properly the instruction to follow. Thanks

I took the tape and split it lengthwise (remember you want it balanced front to back as well as left to right) and applied it on both sides of the stringbed (front and back) and repeated an identical strip on the other side of the racquethead, obviously. At the top (12 o clock) I applied it near the strings, since the bumperguard is in the way and I don't want it coming off when I scrape the court, and laterally (where the bumperguard runs out) I apply it on the outermost edge.

Good luck!

 

[Bolt]

You contradict yourself a few times in your list.

Examples?

 

[andrew_b]

If you know the weight and balance, the swingweight can be estimated from the string setup. For example, James Blake's setup is ~13.4 oz., with a ~12.25" balance. That narrows his swingweight down to a range between 360 and 390. Since his tension is almost maxed (~68 lbs on a 98si head with poly), it means that SW2 would be on the low end of the range, in the low 360s.

What on earth does string tension have to do with swingweight??

Sorry, that's just wrong. Swingweight and string tension are not related to each other, nor by any stretch of the imagination are they functions that can predict each other.

Play well,
Andrew

 

[AJK1]

Oh Dear......

 

[BreakPoint]

Interesting theory until I got to this part which I think makes it sound too paradoxical:

In the vicinity of SW1, adding a gram of lead will add power and reduce spin. But when you are close to SW2, the opposite applies – adding a gram of lead to the hoop will reduce power and increase spin – because now you are on the downward slope of the Swingweight vs. Power Level curve.

I think adding too much weight to the hoop, and thereby increasing the swingweight, will decrease spin because it will make it more difficult to brush up on the ball with the higher racquet head speeds needed to generate heavy topspin.

Besides, I don't think many non-pros could handle swingweights of as high as 365 without a drastic change in their games, strokes, and physical condition, and without their arms and shoulders falling off. I think unless you are very, very strong, you would experience a decrease in both power and spin due to a drastic slowdown in your strokes and racquet head speed with a swingweight that high.

Yes, your shots will be more solid and more accurate, and you'd have more power and control but that's only assuming that you're able to swing the racquet at speeds approaching something close to what you were swinging it before when the swingweight was only 325. Very, very few of us can do that after adding a whopping 40 points to the swingweight.

So this may be good in theory, but I think it fails in practice.

 

[AJK1]

Has anyone thought of sending these theories to **** and seeing what they think of all this!

 

[bertrevert]

Travlerajm has countered the view that this is all too heavy with these previous thoughts:

1. everyone, yes even kids, used to play with 14oz wooden racquets, and you can too
2. you will not notice the weight in groundstrokes, but you will in serves, but he says to take it easy and build up your serve slowly, like doing weights in the gym
3. the lead goes at 12 in the hoop, so once you've got the stroke going it should just swing through

I happen to agree that this added weight would be horrendous, and as an ex MW200g user, any dogfights with that racquet were murder. However, I'm going to give all this a try on my 300g some day soon....

 

[travlerajm]

deleted by author.

 

[Steve H.]

What on earth does string tension have to do with swingweight??

Sorry, that's just wrong. Swingweight and string tension are not related to each other, nor by any stretch of the imagination are they functions that can predict each other.

No, it makes sense. What he's saying is that if you string with higher tension you get lower power, which means that you don't need as much mass in the head to control the shot. So tension and actual swingweight may not be related, but tension and _ideal_ swingweight are.

 

[travlerajm]

deleted by author.

 

[travlerajm]

Sorry, I shouldn't have said "threshold." But what I meant was that the only reason why the power level is coming back down from the maximum peak power level is because the operator is NOT CAPABLE of accelerating the racquet as much due to the increased weight. So the operator will be laboring more with each stroke, than if he were at SW1 achieving the same power. I see this as a disadvantage. But maybe the advantages that you listed would outweigh this disadvantage.

Interesting topic.

I think the idea that you need to accelerate the racquet through the contact point on a groundstroke is a misconception. Rather, you want to have constant reproducible velocity through the contact zone. If you watch the pros, they generally take the racquet head back high on the backswing. The high elevation of the backswing equals high potential energy. This allows gravity to do much of the work of accelerating the racquet. So at SW2, it is not actually that much harder to swing the racquet on a groundstroke, it's just that the force of gravity swings the racquet at a slower speed. The force of your muscular input is the same. The more the swingspeed depends on the moment of inertia, the less it depends on your muscular input, and so the stroke is more fluid and reproducible.

Also, when you are at SW2, gravity is also partly responsible for creating more spin. The high inertia of the racquet helps the racquet swing upwards toward the ball. A high swingweight racquet is naturally pulled upward by inertia just like a pendulum is pulled upward after it passes its nadir.

 

[travlerajm]

Interesting thread, travlerajm. What about string pattern? Would having an 18x20 pattern vs. 16x19, 16x18, etc, have an impact on the curve?

Changing string pattern has the same effect as changing tension. The power level is a function of the deflection of the stringbed.

 

[emcee]

I think it's conceivable at least that added mass can increase spin. You should be able to swing the racquet at almost the same speed with a heavier racquet (to a point) once you get used to it. So that extra force can go to extra spin or something. I've hit heavier spin with my old PS 6.0 95 than my light, whippy Warrior OS...

 

[sureshs]

Breakpoint,

You are missing the point. This concept applies regardless of whether you are the Hulk or a 97-lb weakling. If you have less strength, it simply shifts the Power Level vs. Swingweight curve downward. This means that SW1 would increase and SW2 would decrease. That is, the value of SW1 and SW2 depend on the player. So the Hulk might have SW1 of <300 and SW2 of >400 with a typical frame at mid tension. But your grandma might have SW1 of 345 and SW2 of 355. In each case, the power level is the same at SW2 as it is at SW1.

How is he missing the point? You are again saying that grandma can swing a 355, and he doesn't think so.

 

[Two Fister]

As for the widespread but misinformed notion that spin would be decreased at SW2 relative to SW1, I encourage you (and other skeptics) to test it out for yourself. As long as you do not increase the tension, your spin level at SW2 will exceed your spin level at SW1. And consider that it would not be possible for Nadal to hit with the magnitude of spin that he does if he did not set his racquet up at SW2.

TravelerJam,

Okay, I've currently got 24 inches of lead tape at 3 and 9 on my purestorm (smaller head size). So I'll put 16 inches more at 12 o'clock and that should be close to what you are suggesting. And I'll give it a try.

But from a theoretical standpoint, since the ball really doesn't weigh that much, for a given string set up, the only thing that I can see affecting the speed of vertical rotation of the ball (topspin) as it leaves the strings is the speed of the string bed (vertical component) as it contacts the ball. Are you saying that this speed will be the same at SW1 and SW2? This wouldn't seem right to me based on your definition of SW2. Or are you saying that there is another component to the speed of rotation of the ball other than the speed of the racquet head at impact?

 

[travlerajm]

How is he missing the point? You are again saying that grandma can swing a 355, and he doesn't think so.

Then why does the n1 125 (serious granny stick) have a swingweight of 351?

 

[gregmiata]

Mass replaces speed

I have been reading this thread with much interest and think what is missing is the idea of mass replacing speed. A lighter racquet does swing faster and uses that increased momentum to overcome its relatively lighter mass (compared to the ball) to impart spin, while the heavier racquet can impart the same amount of spin with a slower swing speed because of its larger mass compared to the ball. I like analogies so try this: if you were playing pool and the cue was half the size of the other balls, wouldn't you have to hit it harder (more velocity) to make the other balls travel the same distance on the table?

I am guessing that professionals like that heavier mass because of the pace and amount of spin that the ball is traveling at them is too large for a lighter racquet's swing speed to overcome.

Greg

 

[sureshs]

Then why does the n1 125 (serious granny stick) have a swingweight of 351?

It is 14 points HH, maybe that is why? But it weighs only 9.4 oz. Your numbers have always indicated much heavier static weights too.

And grandma already has arm problems. She will be gone before the effect of this racquet on the arm are known. Also, her opponents just tap the ball over the net, so not much impact there.

Whatever it is, would you call that a maximum performance racquet?

 

[jace112]

IMHO, it's a very confusing thread just for adding lead in the hoop. I think your first messages were much more scientifically accurate and detailed. Sorry...

 

[sureshs]

I have been reading this thread with much interest and think what is missing is the idea of mass replacing speed. A lighter racquet does swing faster and uses that increased momentum to overcome its relatively lighter mass (compared to the ball) to impart spin, while the heavier racquet can impart the same amount of spin with a slower swing speed because of its larger mass compared to the ball. I like analogies so try this: if you were playing pool and the cue was half the size of the other balls, wouldn't you have to hit it harder (more velocity) to make the other balls travel the same distance on the table?

I am guessing that professionals like that heavier mass because of the pace and amount of spin that the ball is traveling at them is too large for a lighter racquet's swing speed to overcome.

Greg

The professionals are also in better physical condition, have better technique, and have no choice in this matter because they have to compete and win at their job. If recreational players swing sticks at SW2, is it going to benefit them or hurt them?

Mind you I am not saying the analysis is wrong. It is the suggestion that club players should add lead to go from SW1 in their stock frame to SW2 that bothers me.

 

[SHG72]

Match results from the new setup??

For those of you who like the new design (i.e., weighting scheme), how has it affected your play? Has your play improved in matches? Are you winning points/games/sets that you were losing in the past?

 

[haerdalis]

I do think one should be a little careful when changing the specs of a racquet. It will put strain on your body in a new way so take it in small increments if you want to be safe.

 

[Rule26]

SW2 is a sliding scale what about polarity?

Travlerajm - (In less techincal terms & I hope I'm not misquoting you either but to better understand what you have stated) It is a sliding scale for SW2: lower stock weight means that the raquet needs to be generally more head heavy and higher stock weight means that the raquet can be more head light to reach the recreational players sw1 of 325 but the non recreational player has advantages to go 25-35 points over based on weight distribution & flex.

The relationship of the stock racquet's inital distribution of weight is also a sliding scale. Is it polarity vs flex? From what i gather, since I really need help with my math, is that some racquets have better potential for this customization than others to keep the weight below 13 oz. Is there a way to calculate this potential in stock raquets?
You have offered a great deal of recommendations for os raquets that best fit this modification but I am trying to look at how to accomplish this on a midsized? Something in the 95 sqin range.

I hope what I'm asking you makes sense, because I'm mathematically challanged when it comes to calculating anything without a $ in front, (Ted Knight Syndrome). In particular, you notes on the the Wilson 95's, prince HT & T 95's and redondo 98 based on their stock weight and balance, which of any can be modified to reach the 255-260 sw2?

Thank you

 

[Two Fister]

while the heavier racquet can impart the same amount of spin with a slower swing speed because of its larger mass compared to the ball. I like analogies so try this: if you were playing pool and the cue was half the size of the other balls, wouldn't you have to hit it harder (more velocity) to make the other balls travel the same distance on the table?

Is the mass of the tennis ball enough (relative to the mass of the racquet) to be significant? Maybe if you were trying to impart topspin on a basketball with a tennis racquet, then I can see how the mass of the racquet would make a difference. The basketball would probably impede the upward motion of the racquet. But if the racquet weighed several pounds, then the upward motion wouldn't be impeded as much. But is the tennis ball really impeding the upward motion of the racquet enough to slow down the spin of the ball in a SW1 racquet vs a SW2 racquet?