How much does SW decrease by shortening?

Discussion in 'Racquets' started by Xizel, Jan 15, 2012.

  1. Xizel

    Xizel Professional

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    By 1/4 and also 5/8. I saw the info in a thread sometime ago, but can't seem to find it again. Thanks for the help.

    Edit: I found that it was 25 units/quarter inch. How about balance and weight changes?
     
    Last edited: Jan 16, 2012
    #1
  2. corners

    corners Legend

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    Jul 31, 2008
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    About 24 units per half inch, 12 per quarter, 6 per eighth.
     
    #2
  3. travlerajm

    travlerajm Hall of Fame

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    Each 0.5" will decrease SW by 16-20 units for most racquets. This range will cover 90% of the racquets out there.

    It can easily be calculated more closely with the parallel axis theorem:

    SW' = SW + M(x^2 + 20x - 2Rx)
    SW' = new swingweight
    SW = startign swingweight
    M = racquet mass (in kg)
    x = amount shortened (in cm)
    R = starting balance (in cm)

    For a 27" racquet starting with 11.2 oz. (0.317kg), 13" balance (33cm), and 330 SW, the new swingweight after shortening to 26.5" (x = 0.5"*2.54 = 1.27cm) will be about 312 (reduced by 18 kg-cm^2). The heavier the starting weight, the more the SW will change.
     
    Last edited: Jan 16, 2012
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