Lightest swingweight on ATP tour?
- Thread starter Shaolin
- Start date
It would help explain why he doesn't ever end up with the high speed bomb in the 150mphs that raonic and other similar size big serving guys occasionally hit.
The fact that he stopped weighting up his racquet would contribute to that last little bit of mph (not that he needs it)
Also he plays a stock racquet, but with a leather grip iirc. So probably+~15 to the SW if I had to guess.
But you must look under the cap grommets...maybe could be a surprise under
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Leather grip would only add 3-5 SW pts at max. Nowhere near 15
D
Deleted member 768841
Guest
Uhhh.......
dr325i
G.O.A.T.
Villain
Professional
Pretty sure a leather grip doesn’t affect SW at all.
dr325i
G.O.A.T.
It does slightly, very slightly.
Extra 10g of static weight but maybe 1 or 2 points if SW
If weights more than a normal grip of course...you can add lead and a normal grip if you choose it....but if you add a Head Calsfkin entire you modify SW sure, are a good amount of leather
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Professional
For what it’s worth, I checked added weight to the handle on the TWU customization worksheet. A 50 gram increase at the top of the handle increases SW 3 points. A 10 gram increase adds 0.6 SW. Considering that only a portion of the weight added from a leather grip is at the top of the handle (obviously it is spread out from the middle of the handle), I think it’s safe to say that no one would notice a SW change of 0.6 (probably more like 0.2).
Shaolin
G.O.A.T.
What do you approximate strung weight as?
dr325i
G.O.A.T.
Add about 35g for strung SW So all of them 335 or less SW
haqq777
Legend
Correct. Have never had an increase in swing weight by adding leather or adding putty to butt cap for as long as I have been playing. And I've always had access to RDC. Anything on the handle is negligible for RDC to read. Have added 5 to 10g on the 7" mark going up from butt cap on the handle many times as well. Swing weight remains absolutely same on machine read out.
D
Deleted member 768841
Guest
It’s nice to know I use more advanced specs than Kyrgios and get worse results.
dr325i
G.O.A.T.
Bevels, feel, added weight and even slight flex change but definitely not the SW influence
P sure there's a 1:1 increase in SW with weight at least, but I assumed it would be slightly more than just that.
Shaolin
G.O.A.T.
Curious who is using the 310s? Thanks
dr325i
G.O.A.T.
Strung...no one really known...
Shaolin
G.O.A.T.
Nishioka. Tested by M&C last year.
Interesting! What stick is that?
El_Yotamo
Hall of Fame
I've seen too many people not understanding what they're talking about when it comes to SW on this thread to ignore. Here's what you guys should know (at least if you're gonna post about it or apply it to your frame):
The SW is one of the mass moments of inertia of a tennis racquet, which in mechanics is defined very loosely as the resistance to rotational motion. You know how something heavier is more difficult to pick up? Something with a higher moment of inertia is more difficult to rotate about the axis at which the moment of inertia is measured (more on that in a sec). Now, because this is rotational motion and not linear motion, moments of inertia are not measured in grams, kilos, pounds, etc. It's easy to get confused because many of the SW measurements we see have values similar to mass measurements, and the word weight is in the SW name, but in no way is that the actual case. This is important because once you understand units of measurement it's a lot easier to understand the underlying physical concept. The units in which SW is measured are mass*length^2, and in the tennis world we use kg*cm^2. This means that both mass and distance have a role here, because to rotate anything about a given axis you have to apply a force some distance away from the axis (called a moment or torque). Ok so why is all of this important? Let's get back to the particular details invlolving SW and the answers to you guys' posed/potential questions. Anyone who's ever measured the SW of a racquet can by now come to understand that the SW is the moment of inertia about an axis which is located approximately 10 cm from the butt of the racquet. The axis itself runs perpendicular to the handle and parallel to the racquet face. Now remember the units by which we measure SW? All we have to do now is understand the physical implications. For those who really want to know what the moment of inertia is and have some basic knowledge in mathematics and mechanics I recommend looking up "inertia tensor" on google. For our case here, we want to know how adding mass at certain places on a racquet will affect the SW. So our units are kg*cm^2, which means that for any mass added, we multiply the amount of mass added in kg by the distance squared of that mass from our axis in cm. Let's for example consider adding 5 g of mass 50 cm away from the butt. The SW increase will be 0.005*40^2=8 kg*cm^2. It's that simple people. How about our leather grip example? That one's a tiny bit more complicated but it's also pretty easy. When our mass added is distributed and part of it is on the axis we need to split into two distributed masses (one below and one above the axis). So let's say our leather grip adds 10 g distributed evenly from the butt to 20 cm from the butt. We split that into two distributed masses: one from 0 to 10 and another from 10 to 20. Now because the mass is uniformly distributed we treat it as two point masses at 5 cm and 15 cm each with 5 g. Now let's do the math: 0.005*(5^2+5^2)=0.25 kg*cm^2. We did it!
I hate to end this informative post on a douchy note, but I genuinely beg of anyone reading this, please please please don't write information online unless you've done the necessary research/learning and actually know what you're talking about. It pains me that I have to write this because most people don't do it but there are too many people who have no clue what they're talking about that mislead and misinform others. Not necessarily on purpose ofc, but the damage is still done.
The SW is one of the mass moments of inertia of a tennis racquet, which in mechanics is defined very loosely as the resistance to rotational motion. You know how something heavier is more difficult to pick up? Something with a higher moment of inertia is more difficult to rotate about the axis at which the moment of inertia is measured (more on that in a sec). Now, because this is rotational motion and not linear motion, moments of inertia are not measured in grams, kilos, pounds, etc. It's easy to get confused because many of the SW measurements we see have values similar to mass measurements, and the word weight is in the SW name, but in no way is that the actual case. This is important because once you understand units of measurement it's a lot easier to understand the underlying physical concept. The units in which SW is measured are mass*length^2, and in the tennis world we use kg*cm^2. This means that both mass and distance have a role here, because to rotate anything about a given axis you have to apply a force some distance away from the axis (called a moment or torque). Ok so why is all of this important? Let's get back to the particular details invlolving SW and the answers to you guys' posed/potential questions. Anyone who's ever measured the SW of a racquet can by now come to understand that the SW is the moment of inertia about an axis which is located approximately 10 cm from the butt of the racquet. The axis itself runs perpendicular to the handle and parallel to the racquet face. Now remember the units by which we measure SW? All we have to do now is understand the physical implications. For those who really want to know what the moment of inertia is and have some basic knowledge in mathematics and mechanics I recommend looking up "inertia tensor" on google. For our case here, we want to know how adding mass at certain places on a racquet will affect the SW. So our units are kg*cm^2, which means that for any mass added, we multiply the amount of mass added in kg by the distance squared of that mass from our axis in cm. Let's for example consider adding 5 g of mass 50 cm away from the butt. The SW increase will be 0.005*40^2=8 kg*cm^2. It's that simple people. How about our leather grip example? That one's a tiny bit more complicated but it's also pretty easy. When our mass added is distributed and part of it is on the axis we need to split into two distributed masses (one below and one above the axis). So let's say our leather grip adds 10 g distributed evenly from the butt to 20 cm from the butt. We split that into two distributed masses: one from 0 to 10 and another from 10 to 20. Now because the mass is uniformly distributed we treat it as two point masses at 5 cm and 15 cm each with 5 g. Now let's do the math: 0.005*(5^2+5^2)=0.25 kg*cm^2. We did it!
I hate to end this informative post on a douchy note, but I genuinely beg of anyone reading this, please please please don't write information online unless you've done the necessary research/learning and actually know what you're talking about. It pains me that I have to write this because most people don't do it but there are too many people who have no clue what they're talking about that mislead and misinform others. Not necessarily on purpose ofc, but the damage is still done.
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Thank you Sheldon¡¡...I know it works like a hammer...as much as SW higher more difficult to handle and more potence if you can accelerate well, but if not your game goes down...but someone here thinks Kyrgios can serve that bombs without lead in his racquet???
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El_Yotamo
Hall of Fame
I don't understand how this has anything to do with what I wrote... But yes it's possible to serve 200 km/h without a SW of 350 kg*cm^2 from my experience.
But a stock Yonex Ai 98 doesn't have that SW!!
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El_Yotamo
Hall of Fame
I wrote without. So it doesn't need to have it.
Voy a escribirlo en español para que entiendas, es posible dar un saque de 200 km/h sin SW de 350 kg*cm^2. Muchos de mis compañeros del equipo en la universidad juegan con raquetas no alteradas y dan saques de 200 km/h regularmente.
For those that don't understand Spanish, I wrote that many of my teammates at uni play stock racquets and regularly reach the 200 km/h mark on serve.
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I dont doubt about it, but I can't believe Nick plays a stock Yonex without any custom...but maybe could be possible
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El_Yotamo
Hall of Fame
It is what it is. The important thing is that each person has their own preferences and that's ok. The game seems to be going lighter, for better or worse. End of the day each individual player should look at themselves and find what works for them regardless of what the pros do.
dr325i
G.O.A.T.
200km/h = 125mph. There are not many pros on ATP that regularly reach that mark on serve.
What School you go to?
uk_skippy
Hall of Fame
While the weight added will vary based on string actually used, general consensus is that string will add approx 18g. Swingweight will go up by approx 30; and the correct measurement of swingweight is kg-cm^2 not g(rams)
EDIT : clarification of correct swingweight formula as highlighted by @travlerajm
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dr325i
G.O.A.T.
I agree on the units however, totally irrelevant in this discussion.
but thank you, an engineer with 30 years of experience missed the units here...
Also, my 95 sq in 16x19 frames add 14-15g of weight strung
Same frame in 18x20 add 18g
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uk_skippy
Hall of Fame
Why irrelevant? Maybe in your view. But if the wrong info is mentioned, surely those who are interested who would like to know the right info.
travlerajm
Talk Tennis Guru
The units should be kg-cm^2 (not kg/cm^2).
uk_skippy
Hall of Fame
I have seen it written as kg-cm^2, kg/cm^2 and kg*cm^2; and would agree that the way I wrote it would indicate that its kg divided by cm^2; whereas the last one would be kg multiplied by cm^2. I'll accept that I wrote it wrong.
El_Yotamo
Hall of Fame
When I say regularly I do not mean every other serve, I mean a couple times at least in a match. Obviously we don't stand out there with a speed gun but the concept is clear enough. I'd like to remain relatively anonymous on these boards though I will say that we're not in the US.
The point being made is that one can get to those speeds using a stock racquet anyway. You don't have to believe it and I'm certainly not one who plays/recommends playing stock racquets but that's the reality.
I thought Rublev was sporting a very high swingweight.
I am intrigued by Fritz. Have been watching some practice session of him on youtube. Such a compact swing, he generates such easy power!
dr325i
G.O.A.T.
Rublev has a high static weight, very HL and low SW
ron schaap
Hall of Fame
Probably the tennis school of Nadal himself at Mallorca? There a too many members on this forum who falsely think we need special gear for good results, because they lack technique .
ron schaap
Hall of Fame
Sw is interesting but what really matters how much energy (impuls and rotations) we can put on tbe ball. (s)weight is lineair in that equation but racquethead speed is quadratic for the resulting kinetic energy. With other words if we manage to swing a light racquet faster than a heavy racquet, the resulting tennis ball leaving the strings will be much faster. So not only we are able to prepare earlier, we can hit a faster ball with a lighter racquet too. Only tbe shock to our arm may feel bit severe. Thats the only price to pay.
travlerajm
Talk Tennis Guru
There is also the fact that depth control is proportional to swingweight.
El_Yotamo
Hall of Fame
While what you write is true for a large part, the reason for my post was people not understanding what SW is and basic facts about it. So I wrote about it.
Now about what you said, the deformation of the racquet at impact and everything that has to do with the racquet's ability to take an incoming ball is important, and the kinetic energy in fact is not the main thing to be considered. For perfectly rigid bodies in vectorial terms the angular momentum equation states that the sum of the torques equals the time derivative of the angular momentum, which is the inertia tensor operating on the angular velocity vector. In terms of analysis if you consider some incoming impulse as the input and can apply a given inertia tensor and initial angular velocity/acceleration in order to find the overall output. Then you need to consider racquet deformation since it's not perfectly rigid, and angular momentum is only conserved for perfectly rigid bodies. If you take the Lagrangian approach then you still need to derive the kinetic energy which again gives something linear with angular velocity. So kinetic energy is interesting but not the main thing to consider in the way you did. And of course vibrations, which themselves are related directly to the inertia tensor and cross-sectional properties, are something to think about always.
The deformation of the ball at impact depends on its incoming velocity and angular velocity as well as everything I mentioned above to do with the racquet, plus it also is related to the strings.
so many factors other than swingweight affect how hard one can hit the ball - headsize, string pattern, string tension, stiffness. Remember that Krygios is using a lighter stick, but he can swing it faster! His motion uses a lot of lag and I bet his racquet speed on serve would be one of—if not THE—fastest on tour. A heavier racquet is useless if you can't swing it effectively. 200km/h is not that hard to achieve on serve with many stock racquets - babolat pure drive, yonex ai98, etc. Most top div 1 college players could crack a serve pretty close with a stock frame.
ron schaap
Hall of Fame
For sure the deformation of the incoming ball is be considered as wel but has nothing to do with the tennis frame. I d say the less deformation of the ball the more energy of the swing is used for the speed of the ball, while we can speak of "elastic" collision as opposed to inelestic collision. Remember how hot a squasball becomes during play. This is all wasted energy. So loser and or softer strings transfer more energy(momentum) and less change of racquet deformation, do you agree?
The only concept is "dwelltime" i m unsure. Does give loser strings and or softer racquets more dwell time during impact and therefore transfer more "momentum"?
