Center of Gravity or CG as it is more commonly referred to in golf, plays a major role in the performance of golf clubs.
Much like Moment of Inertia, CG is a concept in physics that relates to every object on earth, but when it comes to golf it has to do mostly with performance and feel.
Center of Gravity Definition
The standard definition of center of gravity is the point at which the weight of an object is evenly dispersed and all sides are in balance.
A human body has an ever changing CG due to the constant movement and the different positions it can take.
A static object will only ever have a fixed CG and this is the case with golf equipment, including golf balls.
Essentially, CG all comes down to balance and you can supposedly balance any object on a small flat point just beneath its CG.
While CG is mostly found near the middle of an object, it is generally found closer to the face of a golf club due to the face being the thickest and heaviest part of the club.
The hosel is also a heavy part of the golf club and this too is located closer to the face. So basically if you had to draw a cross over the crown of your driver for example with the face pointing upwards the CG would sit somewhere in the top left quadrant closest to the hosel.
The greatest performance factors that CG has is an effect on spin and dynamic loft. Dynamic loft is the actual loft delivered to the ball at impact.
Center of Gravity in Woods
In woods with adjustable weight technology, such as the TaylorMade M1, Callaway Epic, Titleist 917 and many other drivers and fairway woods with such technology, the CG can be altered and will affect the spin, dynamic loft and even the MOI of the club.
Even though the adjustment in CG will be a few millimetres, it can have a drastic impact on the performance of the club.
Moving the CG away from the clubface will promote a higher dynamic loft and more spin at impact. It will also increase the stability, or MOI of the clubhead due to weight being pushed more to the perimeter of the club.
Moving the CG towards the face will lower the launch and spin and make the club more workable and less forgiving.
Shifting weight towards or away from the hosel, as is possible in the TaylorMade M1 driver, adjusts the flight bias of the club, enhancing a draw or fade. This can also help you to straighten out your ball flight if you tend to draw or fade the ball too much.
All of this CG movement in the clubhead will also affect the feel of the club.
A CG that is closer to the face will make the club feel heavier and will make the shaft feel stiffer through the swing. Better players with faster swing speeds will prefer this, as it gives them more control over the flight and spin when swinging the club hard.
Higher handicapped golfers and those with slower swings might battle to square up the face at impact and will often slice the ball. The CG of drivers is different for all brands and this makes it even more important to try out the many different drivers on the market to find the best performance and feel to suit your game.
Center of Gravity in Irons
CG plays a role in the design of irons too. This is most apparent in today’s game improvement irons where stronger materials have allowed for thinner faces and larger cavities to be created. This pushes weight further away from the face and hosel and increases the MOI while also placing the CG lower and further away from the face. The result is a higher launch with more spin that offers a straighter, more forgiving flight and more distance through the lowering of loft per club.
Some models of clubs such as the TaylorMade M1 irons have a fluted hosel design where even more weight has been removed from this area of the club and distributed away from the face to offer even more forgiveness and a CG much further away from the face.
Better players will prefer a more compact clubhead where the CG is closer to the face and sole of the club as this makes the club more workable. This is due to the CG also being the center of the rotational axis of the clubhead and if it is closer to the face, it makes it easier to shape your shots and control the trajectory and spin. This is the same concept in wedges.
As you can see, center of gravity plays a significant role in golf equipment design and modern materials and technology have allowed for big advancements in CG placement in golf clubs.
Some brands are even boasting to have managed to place the CG in such a low location in the clubhead that it completely reduces spin and increases launch to optimise distance significantly. This will once again come down to the specific player as to how much it will affect the performance of the club for them, but it makes choosing your next driver, fairway woods and irons that much more interesting.