By Shawn Zawodni, Club Fitter
I was interested in writing this article for many reasons: 1) we constantly get asked about swing weight during fittings 2) doing a little online research I found that there are very few accurate explanations of what it actually is and 3) I love playing around with different swing weights myself. Almost every article I found said that “swing weight is how heavy a club feels during the swing.” I won’t bother citing any sources because that is what almost every article said. Now that statement on its own is not entirely wrong, but it’s also not entirely accurate. “Feel” is subjective and unique to each individual.
Swing weight is the measurement of where the center of gravity (CG) of a fully assembled club (I’ll refer to this as our system) is located relative to a predetermined point on the club (Fig. 1). The industry standard is a “14-inch fulcrum scale” developed by Ralph Maltby. Our scale happens to be a Golfsmith scale. This is an alphanumeric scale (Fig. 2) ranging from A0 – F0 (actually labeled G10 on our scale).
Figure 1, assembled club on swing weight scale
Figure 2, Alphanumeric swing weight scale
As we move higher on the alphanumeric scale, the closer the CG of the system is located towards the head creating a heavier “feel”. As a reference, most golf clubs are manufactured between C7 and D6 (Fig. 3) with a few exceptions.
Figure 3, swing weight measurement
So why does moving the CG of the system closer to the head produce a heavier “feel”? From a physics perspective, the closer the CG is to the head, the farther away it is from your hands (which happens to be your only point of contact with the system). This produces a greater torque (or moment) about the hands producing a heavier “feel”. Let’s break down the torque equation (Eq.1) to explain higher and lower swing weights.
𝜏 = r F sin(θ)
𝜏 = torque
r = radius
F = force (mass * gravity acting at the point mass or CG of the system)
sin(θ) = angle between F & lever arm r
Equation 1, torque
We are measuring the balance of the system in equilibrium. The only force (F) acting on the system during this measurement is gravity. The measurement is taken with the shaft (lever arm) tangent to the surface of the earth with the force of gravity acting at a 90° (or π/2) angle to the lever arm therefore sin(90°) = 1. This means our torque equation is nothing more than how far the CG of the system is located from our predetermined point of measurement (14” inches from the end of the grip). Assuming we don’t change the force acting on the system, the CG position relative to the fulcrum determines our swing weight.
So now that we learned what swing weight is, how can we change its position? Methods to add swing weight include adding lead tape to the head (Fig. 4), changing to a heavier head weight (in a club with adjustable weight), adding a tip weight to the shaft then reinstalling it into the head, adding length to the club, installing a lighter grip, and Hot Melt (an industrial hot glue that is squirted into the hollow heads of modern metal woods). Methods to decrease swing weight include drilling holes (primarily for wedges), installing a heavier grip, changing to lighter head weight (in a club with adjustable weight), shortening the club, and back weighting the club (add weight to the end of the shaft where the grip is installed. This includes lead tape or many different backweight kits). There are other ways to increase and decrease the swing weight of the system, I just listed the most common methods.
Figure 4, world class lead tape job
So, the important question is: what impact does swing weight have on performance and why does it matter? The simplest answer is for consistency. If the center of gravity of every club in your bag is exactly the same distance from your hands, then everything will have a similar feel. There are of course some exceptions. Two clubs can have identical swing weights but have completely different static weights leading to a different feel. It is simply one more variable that we can control. The more variables we can control, the more consistent your game will be.
Now that we know what swing weight is and how to change it, how do we determine what the right swing weight is for you? Trial and error! The only way to properly determine swing weight is to try different swing weights and see what performs best for you. Swing weight is subjective and unique to each individual and I personally like extremely heavy swing weight. My irons are D8, wedges are E0, and the driver is E6. Quite a few of my coworkers prefer light swing weight in the C9 to D0 range. The point is that everyone likes something different and the only way to figure out what’s right for you is to experiment!
Shawn can be reached at firstname.lastname@example.org.