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Effect of golf shaft length and flex

  1. May 9, 2015 #1
    Hi,
    I'm wondering about the effect of the shaft flex on the impact velocity between the club and the ball. I understand that as I swing down the golf club, the shaft flexes and the club head lags behind. Near the end of the point of impact, the shaft bends forward. Intuitively, I would think that the more the shaft flexes, the more impact speed I get, hence more launch speed.

    However, I've read on several sites that say the this actually decrease the launch velocity of the ball. So I just need help on the clarifications.

    Thanks
     
  2. jcsd
  3. May 9, 2015 #2

    russ_watters

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    Staff: Mentor

    The shaft flex must be matched to your swing acceleration, otherwise the shaft might not straighten as it approaches the ball. More flex for higher acceleration, less flex for lower acceleration.

    Put another way: when a shaft is less flexible, it stores more energy for the same amount of flex because the force required to make it flex is higher.
     
  4. May 9, 2015 #3
    Sry I couldnt quite catch exactly what you said in the final sentence.

    Did you mean that if the shaft flexes more, more energy is used up? So that means the reason why there is less impact speed is because some of the energy is lost due to the flexing of the shaft?
     
  5. May 9, 2015 #4

    russ_watters

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    Staff: Mentor

    No, I mean for the same amount (distance) of flex, a stiffer shaft stores and releases more energy.

    The flexing of the shaft does not generally result in a loss of energy, it is simply an energy storage method. So what matters is storing as much energy as you can and releasing that stored energy at the right time.
     
  6. May 9, 2015 #5
    Thanks. It's starting to make more sense to me now.

    But if I have the same swing speed for both flex shaft and stiff shaft, the flex shaft would obviously flex more and the stiffer shaft would flex less. So which shaft would allow me to get more launch speed of the ball, considering my swing has the same speed, and acceleration?
     
  7. May 9, 2015 #6

    russ_watters

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    Staff: Mentor

    Well that's just it -- it depends on what the speed and acceleration of your swing actually is. If you have a low swing speed/acceleration, a lower flex will be better. If you have a higher swing speed/acceleration, a stiffer flex will be better. If you choose wrong:

    If you have a high swing speed and choose a low flex, it won't rebound and release the stored energy onto the ball. Worse, the fact that the shaft will still be flexed at impact means the club head will be open and drag, resulting in a high slice.

    If you have a low swing speed and choose a stiff flex, it won't store any energy, so it won't help you hit the ball harder.
     
  8. May 10, 2015 #7
    By "low flex", do you mean high flexibility (flex more)?
    It cant be low flexibility( flex less )because then that would be a stiff flex.
    Tks
     
  9. May 10, 2015 #8

    russ_watters

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    Staff: Mentor

    Yes, you are correct: I worded that poorly.
     
  10. May 10, 2015 #9
    Ok I understand now.
    Thanks a lot
     
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