How is this possible?

Discussion in 'Racquets' started by Adrupert, Jan 6, 2008.

  1. Adrupert

    Adrupert New User

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    Might be a nooby question but I don't get how the Microgel Prestige can have such a lower swingweight than the K-six one when you look at the specs they are almost identical. Can anyone tell me why?

    Head Size:
    93 sq. in. / 600 sq. cm.
    Length: 27 inches / 69 cm
    Strung Weight: 12.2oz / 346g
    Balance: 7pts Head Light
    Swingweight: 328
    Stiffness: 63
    Beam Width: 19 mm Straight Beam


    Head Size:
    95 sq. in. / 613 sq. cm.
    Length: 27 inches / 69 cm
    Strung Weight: 12.3oz / 349g
    Balance: 8pts Head Light
    Swingweight: 340
    Stiffness: 69
    Beam Width: 22 mm Straight Beam
     
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  2. Zachol82

    Zachol82 Professional

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    Well the Microgel's static weight is already lower. I'm not sure if the stiffness and beam width would affect the swingweight...but I'm sure it does somehow.
     
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  3. Adrupert

    Adrupert New User

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    It must, because while the static weight is lower, the balance is also lower which should counter the effects of a a lower weight on swingweight.
     
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  4. Agent Orynge

    Agent Orynge Professional

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    The balance of a racquet only tells you where the average weight of the racquet is, but not how the weight is distributed. Swingweight is not calculated from the very butt of the racquet, but from a point somewhere along the handle. Without being a physics expert myself, my best guess as to why this is done is because the center of the centrifugal force is somewhere nearer the top of your hand. Of course, I may be totally off base here and anyone who know's better is more than welcome to correct and/or harangue me for doling out false information.

    At any rate, if the distribution of weight below the balance point is uneven, with a better part of the weight being below the point from where the swingweight is measured, that might account for a big discrepancy in swingweight between two otherwise similar frames.
     
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  5. RestockingTues

    RestockingTues Banned

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    The swing weight of the six one is higher because the head is bigger, and the beam width is thicker. That itty bitty 2 inch sq. and the 3 mm will account for that much more air resistance.
     
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  6. [d]ragon

    [d]ragon Hall of Fame

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    lower static weight + different weigh distributions
     
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  7. Bud

    Bud Bionic Poster

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    Bingo! Weight distribution and air resistance will change the SW a bit. Static weight and balance are the biggies, though.
     
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  8. Agent Orynge

    Agent Orynge Professional

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    Air resistance is factored into swingweight? Alright, I'll bite; What's the formula for calculating swingweight?
     
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  9. Midlife crisis

    Midlife crisis Hall of Fame

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    Swingweight is calculated by clamping a racquet into a Babolat RDC machine. The racquet is then rotated through an arc with the center of axis 10 cm up from the butt of the racquet. The swingweight is really a measure of inertia around the center of rotation, and does not take air resistance into account.

    As to why the swingweights are different, it depends on the mass distribution. For instance, you can have a racquet where the weight is predominantly at both ends of the racquet, and one with the weight predominantly at the center of the racquet. These may well have the exact same static weight and balance, but the swingweight will vary significantly, with the racquet that has more weight distributed towards the ends of the racquet having the higher swingweight.
     
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  10. RestockingTues

    RestockingTues Banned

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    Double fault :oops:
     
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  11. RestockingTues

    RestockingTues Banned

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    Thanks for the reply MC, I learned something new today :D
     
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  12. Agent Orynge

    Agent Orynge Professional

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    Yes, thanks Midlife for double-tapping my point.
     
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  13. Midlife crisis

    Midlife crisis Hall of Fame

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    #13

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