Great Jack Kramer says lighter racquet so more power

Discussion in 'Tennis Tips/Instruction' started by boramiNYC, May 1, 2012.

  1. LeeD

    LeeD Bionic Poster

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    Way to go, genius!
    You not only put your own foot in your mouth, you lost all credibility.
    Read what you posted, add a 15 oz racket, genius.
     
  2. OTMPut

    OTMPut Hall of Fame

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    take it easy old man.

    read my q again: does light racquet implies higher swing speed mean you can swing infinitely faster with zero mass in your hand? it clearly looks absurd. but all the equations produced so far implies that.

    evidently the supposition that is being shown out as "truth" is just that: a mere supposition that perhaps works on very narrow range.
     
  3. LeeD

    LeeD Bionic Poster

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    yeah, immediately after posting my post, I checked quite a few of yours, and every one seems insightful and filled with realistic thoughts...
    And I knew you meant in the context of reality...rackets from 9 - 13 oz.
     
  4. boramiNYC

    boramiNYC Hall of Fame

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    There is limit how one can swing bare arm from technique and when racquet is held the stress to the weakest joint, wrist (accelerating and decelerating) becomes major limiting factor. The heavier the swing will get slower because of the physical stress. But, it's a personal choice to balance the swing speed, spin, and weight of the racquet. It's still the fact that lighter racquet allows faster swing speed as long as it's not limited by the technique.
     
  5. toly

    toly Hall of Fame

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    I disagree.

    Let’s analyze javelin throwing. According to IAAF minimum weight of javelin is 800 g (28 oz). Javelin throw word record is 105 m. If they throw 10 lb javelin, certainly the world record will be much less.

    What about darts? Most people throw darts that weigh between 20-25 grams.
    Imagine that javelin throwers toss 25 g dart instead of 800 g javelin. Obviously, that in case of darts there also would be much less distance because they are too light for our body.

    Of cause you are right about technique.

    So, to maximize the racquet speed, even with ideal technique, we should optimize its weight, moment of inertia, and polarization!!!:)
     
    Last edited: May 7, 2012
  6. bhupaes

    bhupaes Professional

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    Very good post. The key, IMO, is understanding why one can't throw a 25g dart as far as one can throw a javelin. It's not because of air resistance. The 25g weight does not create an eccentric load on the arm/shoulder that is explosive enough (the "stretch"). You may have experienced it while trying to skim flattish stones on a pond or river - the stone has to be sufficiently heavy for you to fling it fast enough to bounce. It is not unreasonable to expect that tennis racquets would also have optimal parameters for racquet head speed that would vary with individual players, based on their physical attributes.
     
  7. DBrickshaw

    DBrickshaw New User

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    Just found this thread so ill throw in my 2 cents.

    The way i see it is that part of it is ur muscles can only contract so fast so a little extra weight doesnt make much of a diff in swing speed.

    Also adding arm/body weight into the collision isnt quite accurate because your wrist is flexible and will give a bit at contact even when held firm. Having more weight in the racquet helps the racquet dominate the collision and makes ur wrist give less at impact.
     
  8. 1HBH Rocks

    1HBH Rocks Semi-Pro

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    It does seem ridiculous. Envision a graphic plotting swing speed with proper technique versus racket weight (the later being the independant variable). I bet you'd probably see a curve which diminishes over the whole domain until the racket gets so heavy that you can't even lift it. At the beginning of it, there would be a plateau or something resembling it and, then, the swing speed decrease would gradually get more vertical before getting back to an other plateau. I would also be ready to maintain that a certain amount of weight might do better than an absence of weight as it may help you get your muscles stretched a little further, thus enabling yourself to swing with the helpful contribution of faster contractions.

    I would see it being drawn like this:
    [​IMG]
     
  9. sureshs

    sureshs Bionic Poster

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    But in tennis you don't throw the racket.

    If you take a pen and swing it, does it swing much less fast than a tennis racket (near the base where you are holding it)? I don't think so.

    I am also suspicious about the darts vs javelin argument. You cannot hold a dart as comfortably as you hold a javelin. Air resistance also plays a significant role. A slight deviation from the intended path with cause further movement away from the path due to air effects, compared to a javelin which will be able to maintain its path.

    I think there is a psychological feedback effect in the sense that you may not exert as much force when throwing a dart because your brain is telling you it is a light object. But if you do, I am not sure there will be a difference.

    Edit: I can see a case to be made on the grounds that pulling a javelin back builds up potential energy in the muscles, which is released as kinetic energy. But then the lesser build up of energy for pulling back a dart should be enough for the dart! Great question though.
     
    Last edited: May 7, 2012
  10. GuyClinch

    GuyClinch Hall of Fame

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    The motion of swinging a racquet is very close to throwing - so while you don't technically let go of a racquet and throw it biomechanically its similiar. Hence you will hear about throwing the racquet into the court for practicing your serve..

    Toly is right in his javelin comparison IMHO - and the poster who mentioned throwing golf ball vs. baseball was also correct.

    Again there is some weight where you can swing pretty fast - and thus generate the most force. If the weight is much higher - you will swing slower - and if the weight is much lower you might not swing any faster at all..or about the same speed - thus generating less force.

    IMHO what I noticed about very light racquet is they let you accelerate the racquet with a very short backswing. So you can use a very light racquet very well with crappy strokes.

    But if you have a longer swing/better shoulder turn etc - you can generate more force with the heavier racquet in most circumstances.

    The key is picking a racquet that fits your game and your strength and leverage. A taller bigger player is going to do better with a heavier racquet IMHO. The main reason for this is that the taller bigger player will be able to swing a heavy racquet nearly as fast as a light one and generate alot more power..

    OTOH 80 year old women should swing very light racquets - as they will generate most power with a racquet like that..additional weight will put a weakling swing speed right in the toliet..
    Your game matters some as well. 3.0-3.5 mediocre players are often going to play better with a ligher racquet - as it seems anecdotally anyway those racquets can reach 'maximal velocity' with what feels like zero backswing.. So if you are late - those very light racquets can save you. If you are late with a heavy racquet - you feel like you are screwed.

    Seems to me we can end this debate by getting say Ton Lars to serve a bunch of balls with the lightest racquet to a 16oz one - and compare the serve speed via radar gun. My gut feeling is the biggest serving racquets will be on the heavier side and that Jack Kramer is wrong.

    In fact I think they did an experiment where pros were able to serve extremely hard with heavy wood racquets..
     
    Last edited: May 7, 2012
  11. DBrickshaw

    DBrickshaw New User

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    Dang ya beat me to it
     
  12. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    ^ Similar but not the same. I throw balls much better with my right arm than my left. However, I serve much better with my left arm than my right (even now, with my limited left shoulder function, my lefty serve is better). I've come across a number of other players who also throw ball better with one arm yet, when it comes to the serve, the opposite arm is better. This is a clear indication that the motions, while similar, are NOT the same.
     
  13. user92626

    user92626 Legend

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    Not true.

    Any weight on your hand will potentially slower down your swing than without. Heavier weight will make the swing slower. Reverse is also true, lighter potentially allows faster swing. This is ...basic physics.

    But it gets confusing for us because at the lightest weight, ie empty hand, your swing/slap maxes out at a certain speed or your brain tells it to stop there before you risk injury, ie dislocating shoulder, giving you an impression that your swing is slower. But your could likely slap with your empty hand much faster than you swing with any racket.

    This is purely "speed" talk. Toly is right. With a racket you need to figure out the optimal weight and your tendencies.
     
    Last edited: May 7, 2012
  14. GuyClinch

    GuyClinch Hall of Fame

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    So clearly here heavier isn't faster - but that's pretty close when you consider how much more flexible wood is then a modern racquet.
     
  15. sureshs

    sureshs Bionic Poster

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    We were discussing all strokes, not just the serve.

    But try this. Swing a pen like a forehand now, holding it in the usual tennis grip. Or your cell phone if you think it makes for a more comfortable grip.

    Can you confidently say that the place you are holding the pen/cell phone is swinging slower than it would if it were a frame? Don't go by intuition - just do it and tell me.
     
  16. GuyClinch

    GuyClinch Hall of Fame

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    It might be slower - but will it impart less overall power to the ball? That's the critical question. A heavier racquets mass will impart more power - and that can more then compensate for any loss of swing speed.

    If the swinger is strong - then he will be swinging with almost the same speed - but a significantly heavier racquet and thus generating more power..
     
  17. GuyClinch

    GuyClinch Hall of Fame

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    I can't notice much difference. Though I CAN hit a baseball much farther with an aluminum bat then with a plastic one. The plastic bat is much lighter - my swing speed is higher (or so it feels) but the ball won't travel nearly as far. I noticed I could hit a wiffle ball farther as well - though its harder to connect on the ball because the bat speed is slower.

    And FWIW the forehand and backhand are still very similiar to throws. A backhand is much like a frisbee throw - and a forehand is similiar to a sidearm toss. Biomechanically all the strokes are similar to throws..

    Again we could test this and end the theoretical physics debate. I think again people will serve as big or bigger with heavy racquets. Actually if you could switch racquets my gut feeling is that people would serve with fairly heavy racquets and then use lighter racquets for the rallies. Reason being - as I explained before the lighter racquets let you accelerate out of mistakes easier..
     
  18. user92626

    user92626 Legend

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    GC,

    The paragraph I quoted you was about speed, not power.
    Suresh is correct. Swinging a pen/cell phone is definitely faster than swinging any tennis racket (the speed of your hand).

    Anyway, not sure you guys are debating here. To swing a racket effectively, many things need be considered, namely your strength, your reaction time, your tendency, discipline with the strokes, the amount of time you wanna play, your favorite polarization feel, on and on...
     
  19. toly

    toly Hall of Fame

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    Yes, I played with stones. I definitely know that with very light stone there will be no high speed. Increasing stone’s weight increases its speed. This increase is to a certain maximum and a further increase in weight leads to a decrease in velocity.:shock:
     
  20. sureshs

    sureshs Bionic Poster

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    Yes, the speed of the plastic bat may be same or higher, but the resulting shot will be heavier with the tennis frame. I am also not sure that the plastic bat will swing faster - below a certain weight, the speed may not increase. This is because the swing is not instantaneous. At some time, feedback will tell the brain this is a pencil, don't put the same energy.
     
  21. GuyClinch

    GuyClinch Hall of Fame

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    Thinking about this a little more - golf is the sport to look at. I don't play much golf - but this is the exact kind of problem that they study alot..

    I saw this table looking around the web:

    mass mph e ball speed
    0.110 117 0.769 146 1.247
    0.130 116 0.770 152 1.307
    0.150 114 0.774 155 1.358
    0.170 111 0.779 155 1.400
    0.190 109 0.783 156 1.435
    0.210 107 0.786 157 1.465
    0.230 104 0.791 155 1.493
    0.250 102 0.793 154 1.514

    So as you can see the mass of the club more then doubles - but the club speed only falls a small amount.

    This is why IMHO the idea that lighter racquets = more power is simply not true. The heavier clubs produced more power. Likewise sometimes heavier racquets will produce more power then light ones.

    For very strong players - more power will be generated by a heavier racquet - perhaps even heavier then the wood racquets of old.

    Kramer is probably generally right because for MOST players a lighter racquet then the old wood racquets wood be most power. But for a big strong pro today - its not clear at all.

    But his general idea that lighter = more power is really untrue for modern players who are already using fairly light racquets..
     
  22. sureshs

    sureshs Bionic Poster

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    If a light stone and heavy stone had the same cross-section, the air drag will depend on the square of the velocity. Even if the lighter stone emerged with the same speed as the heavier stone, its velocity will diminish because the same drag force will create more deceleration. You need to compare the instantaneous speed at delivery, not later. That speed is the speed of the hand. The heavier stone is less affected by drag, and hence appears to maintain its speed longer, and moves a longer distance. I think in outer space, they will behave the same.
     
  23. boramiNYC

    boramiNYC Hall of Fame

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    I'm sure you know but, there's a big difference between javelin and dart. Purpose. One as far as you can, the other as precise as you can in a limited space. Tennis is somewhere in between. Also throwing and swinging are quite different in the need to hold on to the racquet and recovery.

    I think use of joints is critical. For modern pro game where more wrist is utilized in conjunction with other joints, the weight of the racquet decreased from 14oz+ to 12-13oz. And the size of the grip got smaller too.

    The issue of recovery is also critical since tennis is not a one swing game. I agree there are many many factors to consider to make the weight choice. Even style of play. But, in general, for the same level of play, if the racquet is doing a lot of work, the player doesn't have to and vice versa.
     
  24. sureshs

    sureshs Bionic Poster

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    Choose a 11.5 strung weight, and call it a day. You should be able to maximize your potential with it, till you come to the point where you REALLY REALLY know what you want and need at your 6.0 level, and then you will not be posting here any more.
     
  25. GuyClinch

    GuyClinch Hall of Fame

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    ^^^I play with an 11.5 - so I agree that's a pretty good starting point. But that doesn't really address Kramer theory that lighter racquets are more powerful which is pretty inaccurate overall..

    Modern racquets are more powerful then those wood ones - but weight is only part of the reason why..
     
  26. toly

    toly Hall of Fame

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    Even if a big and a small stone have the same density, the light stone would have more problems with air resistance. The weight of the stone (ball) increases as R^3, but cross-section changes as R^2. That’s why a grain of sand (very small stone) can fly in the air, but big stone never. Big bird needs much large wings than small one.

    Here I’m talking exclusively about perceived racquet weight and brain tricks. See for example - Hand and Brain The Neurophysiology and Psychology of Hand Movements - Alan M. Wing, Patrick Haggard, J. Randall Flanagan.
    Btw, I practically don’t know anything about this stuff, this is just hunch.:)
     
    Last edited: May 7, 2012
  27. Power Player

    Power Player G.O.A.T.

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    Kind of. I did this..went to 325 grams again and really liked it. I also fixed my prep at the same time..really got my offhand involved in my strokes and learned to get my whole body into every shot. Once that happened, 325 seemed too light again, and 345 seems a lot better. Same racquet speed, but more controlled hitting. I also clearly hit a harder and heavier ball with this racquet weight.

    (I'm not a 6.0 :cry: )
     

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