How Are We Fitting Golf Clubs Today

Fitting With a Launch Monitor

Fitting with the Launch Monitor and that measures the Launch Angle off the tee optimizes the carry of the ball for the shaft and club head combination you are hitting and your club head speed. You must remember however that optimum carry does not mean optimum distance. Again, if you are not using the shaft that best fits your swing you are not going to get the best possible results. You must select the shaft prior to using a Launch Monitor for determining optimum launch angle and club head loft. What the launch monitor is best used for then, is selecting the proper face loft of the club head.

Fitting With Club Head Speed

Club Head Speed has been used by the industry as a simple approach to selecting a shaft flex range. However, there is no scientific relationship between club head speed and shaft reaction. It is only some ones opinion to satisfy the better player’s ego, in the way the industry uses it. It has been experienced many times, that different players with the same club head speed, who fit themselves by trial and error, do not pick the same stiffness shaft or stiffness change from club to club, as the industry builds sets, to achieve their “best performance”.

Fitting With Tempo

Tempo is measured as the time between club take away and return to ball impact. This technique has a better scientific relationship to the clubs shaft reaction than fitting with club head speed but still lacks the refinement to accurately recommend a shaft stiffness. Within tempo there can be to many variations. The length of the swing and the time spent in each segment of the swing can vary greatly. For further explanation see our fitting technology page.

Fitting with the Determinator

The Determinator is a simulated club that has a slide weight located in the head that is supposed to record the peak acceleration or load during the swing. The faults are that it does not have an associated time with it, and it only measures full accelerations in the direction from heel to toe of the club head. If the peak acceleration occurs when the face is closing, the full value of that acceleration is not recorded. The only time a peak acceleration can be recorded is when the club head is parallel with the plane of the swing. Plus only recording peak load during the swing the critical timing factor is missing.

Fitting with the Shaft Lab

The Shaft Lab was a follow on to the Determinator, using a dedicated club instrumented with strain gages to record shaft loading versus time. Even though this is a good approach the Shaft Lab only uses the magnitude of the load as a fitting parameter and no timing parameters are used to relate the club reaction to the swing. This system is really a modification of club head speed in that the more area under the load curve the higher the club head speed. If two players have the same area under their curves, but different peak loads, the one with the higher peak load will get a stiffer club than the other. This is correct in many cases but with out the timing parameter being taken into account the accuracy and reliability is questionable. This is because the higher peak load could release the club earlier in the swing then the player with the same area under the curve or same swing speed that would release the club later. Any player that generates a lot of area under the curve without a high peak will be a late releaser where a player generating club head speed with a high peak load can have a release that occurs early, late or any time in between.

Fitting With the Mizuno Shaft Optimizer

The Mizuno Company has developed an on the club system similar to the FitChip shaft fitting system. However there are significant differences in their approach to the final results. First of all they use a dedicated iron of single length which does not allow for finding the slope that the set of irons should be built on to fit the players swing progression through a set of irons. Therefore if their recommendations are accurate for that club length it does not mean it is accurate for the full set of clubs. With our experience from successfull, full set, FitChip fittings we have found that less the 5% of players fall on the standard industry slope of about 4.3 cpm per club. However, obviously Mizuno has chosen to make their “custom clubs” on the standard industry slope. Secondly they are doing irons only. The third discrepancy in their method of finding what they call a “release factor” is based on a club turn around time at the top of the swing. From this turn around time they estimate a “release factor” from 1 to 9 and relate that number to available off the shelf shafts. Again from our findings with FitChip fitting this limits them to accurately fitting only 40% of the players if their approach to selecting the “release factor” is accurate. We have had a chance to fit three players that were dissatisfied with the Mizuno fitting results and in all cases found that our successful fitting recommendation was drastically different then theirs and proved to provide better and in all cases found that our successful fitting recommendation was drastically different then theirs and proved to provide better results then theirs. Thus, the accuracy of their approach is at the best questionable. If we study the Mizuno fitting chart in Figure 11 the Release factor is not considered in the chart unless they consider it in a secondary manner with Tempo. From a shaft mechanics stand point the release factor should be a primary consideration and have a much greater affect on shaft selection than shown here for Tempo.

Fitting by Trial and Error

The trial and error method is the best of these fitting systems if you can afford the time and cost to do a thorough test. Many of the playing professionals have successfully used this process to find the shafts they need for the best performance. These professionals have the time and the access to the wide variety of shafts necessary to successfully complete the trial and error process. The other requirement that the professional provides this process is feel.

How the Golf Shaft Fittings Should be Done

The FitChip Shaft Fitting System was developed to accurately address the mechanics of the shafts response to an individuals golf swing. This is accomplished by recording data at every .002 seconds during the down swing and identifying the shaft loading and unloading pattern for that individual player and matching the shaft to the players swing timing.

I would like to redefine “shaft loading” as stated by Jeff Jackson of Golf Works. Even though it can occur at the transition point between back swing and down swing, for most players the peak load occurs at some place during the downswing. The timing of this loading and most importantly the start of unloading is the key factor in club fitting. The key parameter that FitChip uses in selecting a shaft is the time between the start of unloading or shaft release and ball impact. The golf shaft is a spring. Depending on the stiffness of that spring it takes a certain amount of time for the spring to recover from the deflected position to the neutral position (for the golf shaft, straight). It is at this neutral position that the golf shaft reaches its greatest effectiveness (maximum speed and club face square). As some may have suggested, if ball impact occurs at peak loading, the shaft will still be flexed and be much less than effective in aiding the golfer. Based on spring/shaft mechanics the stiffer the spring the shorter the time of recovery. The natural frequency of the golf club describes this recovery time and the mechanism that drives the shaft back to straight upon release. Therefore the earlier the release is in the swing the softer the shaft and the later the release the stiffer the shaft. You will quickly find out using this system that shaft selection has nothing to do with club head speed as the industry has used it in the past. In fact I can show you, that if two players have the same time between release and ball impact, the one with the higher speed needs a softer shaft. This occurs because there are two mechanisms acting on the shaft to return it to straight and square. The first one, which we all understand is the spring action of the shaft that is described by natural frequency. The second one is the centrifugal force pulling down on the weight of the head to straighten the shaft and is a direct function of club head speed. Since this Club head speed induced force is helping the spring action the spring action needs to be reduced to get the correct timing to be back to straight and square at the time of impact. Then since the high club head speed player gets more help from club head speed he would need the shaft with a lower frequency (softer shaft). Both of these timing mechanisms are accounted for in the FitChip Shaft Fitting System.

The FitChip analyzes this timing and club release problem and selects the clubs natural frequency that will return it to straight and square at ball impact. No other system available today for club fitting can identify the point of club release accurately during the swing. This timing is what best creates the feel and timing between the player and his clubs. The data collected by the FitChip (up to 84 full swings) can be downloaded to any computer to view the pertinent individual swing data. You will find that many players have double loads and releases that make the process even more difficult.