Swing-Weights, Counter Balancing & MOI: Part 1
BY Paul Smith
There are three hot topics of conversation at this moment in time when it comes to how to build a golf club. Swing Weights, Counterbalancing and MOI (Moment of Inertia).
In Part One we will address the old school method of matching the feel of a club via its Swing Weight and follow on with just a brief look at Counter Balancing which is gaining some influence in the US market. Part Two will look at what MOI actually is and how it potentially changes clubmakers views on Swing Weighting clubs.
Clubs have traditionally been measured on a Swing Weight gauge. This device allows us to measure the total club head feel in order to achieve a continuity amongst our clubs.
Low lofted irons start off lightest in weight (eg. A 3 iron head may weigh 240g) and because they have longer shafts they seem heavier in your hands due to the greater leverage effect. The higher the iron number the heavier the clubhead (eg a pitching wedge may weigh 290g) because the shorter shafts require a heavier head to continue the relative feel. Historically the only exception to the rule has been the Sand Wedge. Its job has been to plough into and throw a pad of sand and lift the ball up. The heavier head has always felt better to do this more strenuous job.
Historically steel shafted (125 gram) irons have been measured around a D0-D1 mark on a Swing Weight Gauge. Graphite shafts (60-90 gram) have a much lower total club weight therefore swing weights and head combinations have dropped to as low as C4-C5. The higher the letter and number the more you can feel the head of the club. So you will feel a D0 clubhead more than a C4.
As a result, in the early days of lightweight graphite shafts many players may have shied away from them as they lost the feel for where their clubhead was going.
Swing Weights can be raised to allow for more clubhead feel by adding some weight, either down the shaft using lead powder, at the bottom of the shaft using a lead plug, stuck to the clubhead using lead tape or at the base of the hosel using a weight port filled with lead.
Each mark on the Swing Weight Gauge corresponds to approximately 2 grams in weight. Given that graphite shafts are almost half the weight of a steel shaft there is plenty of room to add weight to a clubhead.
Players blind tested cannot usually tell the difference of a 1 point Swing Weight change but many can tell a 2 point change (Fig. 3 above).
All of these changes deal with the feel of the club to the player. Higher Swing Weights may help players with faster tempos to control their initial downswing a little better. Slower tempo players may prefer a lighter Swing Weight however there is nothing wrong with them also having a higher reading on their clubs if they like that feel.
In all cases the ideal is that all a player’s clubs are within a Swing Weight point of each other so that they all feel the same.
Swing Weights for drivers and fairway woods vary considerably especially since the advent of super light-weight shafts. This is something to keep in mind if you are thinking of changing the shaft in your driver as you may need to change the weight of the head to maintain its feel.
There has long been a school of thought that the ideal club would be weightless. The logic being that something weighing less is easier to move than something heavy. However, there are many practical issues with a weightless club feel in relation to what is actually happening with the club. For example, designs such as the 1980’s Featherlites never sold well as the heads were so light that players could not control the clubs.
In most cases to increase clubhead feel, more swing-weight points are added to the clubhead. As we have demonstrated this involves adding just a few grams to the head end of the shaft or lead tape to the head itself. However, there is a school of thought that to increase the overall feel of the club you can increase the total weight of the club at the butt end. Counter balancing see us adding weights near the grip.
This may seem a little strange as it will indeed reduce the Swing Weight of the club. Tour players in the US have tried this method and found it has helped their game, especially with their drivers which contain such light weight shafts these days. But how would this approach help the average player?
Researchers at Golfsmith recently conducted a test with 15 players with an average Handicap of 11.5, an average age of 35 and an average swing speed of 95 mph. Five test clubs were built to the same specs apart from differing counter balanced weights in the grips. To cut a long story short, each player improved length off the tee. It may not have been the same weight in the club for each player that went furthest but each player found one weight that suited their swing better. I am sure there will be more research to come on this topic.
Putters seem to benefit a lot from Counter Balancing. The increased total weight of the club gives more overall feel and players often notice a marked increase in their sense of what is going on with the putter in their hands.
So Swing Weights and Counter Balancing are all about feel and there is no cut and dried answer to what will work for each player. There is a feel they will like and as a clubmaker it is our role to open up the possibilities.