DonM They knock swing weight because it is old and seems arbitrary. Well it’s just moi matching at 14” from the butt. The new moi matching is at the butt itself. How do we know where the pivot point should actually be? That’s my argument.
scotts33 BTW, I should add the target number for MoI heft matching also changes with the shaft weight and balance point of shaft used.
The weight on a fulcrum and the frequency of a pendulum are two different ways to measure the same thing!!! So one is not more scientific then the other, they both are a measure for MOI. It can be proven (given grips and uncut shafts weigh the same and have the same centre of gravity) that a matched set build on a fulcrum will also match on a certain pendulum. It's just a matter of determining the corresponding fulcrum point and rotational axis :
the 14" traditional swingweight fulcrum point corresponds to a pendulum with the axis 8.4" outside the butt end (rotation with club armed)
the traditional MOI measured with a pendulum at the butt end (release of the club) corresponds to a 18.2" fulcrum
Rotational Axis = (Fulcrum Point - 18.2) * 2 ; with Rotational Axis and Fulcrum Point measured from the butt end of the club towards the clubhead
The difference is that SW matches the feel (resistance) at the beginning and acceleration of the downswing and MOI matches the feel at the release of the club. In short:
- in a MOI set shorter clubs will feel heavier during accelertion and longer clubs lighter, but they will all release the same -> ball should always be played in the same position in the stands.
- SW clubs will all feel the same during acceleration but the shorter clubs will have a lower MOI at the butt, so they will release earlier then longer clubs -> the ball should be placed more at the back in the stands for shorter clubs and more to front for longer clubs.
I guess there is no size fits all; some players prefer to have the same resistance during acceleration (SW) in order to develop a consistant swing, others prefer to have the same release (MOI). And those who want it all should be playing single lenght clubs. 🙂
