Bonus Tip #19: High MOI and CG Placement
MOI and CG that matters
Over the years golf equipment has made great leaps in technology, becoming more forgiving and opening the doors for more people to enjoy the game. One of the key factors to this leap is the recognition and experimentation with MOI (moment of inertia) and CG (center of gravity) placement. This technology is increasingly prevalent in Drivers and Putters, in both cases engineer’s have moved the weight backward in clubhead. Moving this weight makes the clubs much more forgiving on off center hits due to a higher moment of inertia. With this increase in technology it becomes more important to give these clubs a try and see how they can benefit your game.
What is MOI?
MOI is up there with the regularly repeated words and phrases equipment manufacturers use to explain the performance benefits of their clubs.
Let’s start with what it stands for: Moment of Inertia. You may hear some people just refer to a golf club as having ‘high inertia’. That’s a concept with is actually easier to understand. Inertia is described as: “Inertia is the property of matter by which it retains its state of rest or its velocity along a straight line so long as it is not acted upon by an external force.”
For a proper definition: “It is a rotating body’s resistance to angular acceleration or deceleration, equal to the product of the mass and the square of its perpendicular distance from the axis of rotation.” So when we talk about ‘moment of inertia’ in relation to a golf club you’ll often hear people also say it’s a golf club’s ‘resistance to twisting’ when it comes into impact with the ball.
If the ball was to strike the toe of the driver in a club with low MOI it would turn the club face away from the intended target. It would result in more of a deflection than a full-on blow to the ball.
So we can see why a driver or a putter with high MOI would be a good thing, right?
Think about a sledge-hammer. That’s got high MOI. It would be your tool of choice for knocking a brick wall down.
CG stands for center of gravity and in a golf club head it is the point that all of the weight is acting through. If you drew a line through all the different vertical and horizontal balance points of the club then the intersection of all those lines is the center of gravity.
Why is Center of Gravity important for golfers?
CG is one of the hottest topics in the equipment world as it bestows many of the flight characteristics of the golf ball from the club.
A low center of gravity produces lower backspin and higher launch conditions whilst a higher center of gravity produces the opposite effect.
CG can also be controlled from left to right, so if it is closer to the heel of the club it produces more draw spin which is good for countering slices which a lot of players struggle with.
CG can also be moved vertically as well as forward and backward in the club head with a low-forward position decreasing the amount of spin.
How is Center of Gravity changed?
The CG is manipulated by moving weight within the club head. When manufacturers design golf clubs they determine who the club is aimed at and using data from testing position the weight in the most advantageous position for that player. For example moving the weight towards the heel promotes a draw spin and counteracts slices.
Some clubs allow the golfer to move this weight around for themselves either left to right (see below) or in some cases vertically within the club head.
Ask about the best clubs for you at our pro-shop. Our friendly, knowledgeable staff can offer you the advice that makes sure you play at your best. All clubs and club accessories can be ordered through the Granite Springs Pro Shop.