An Example Driver Fitting

I have promised my younger son, David, that I would do a driver fitting for him. He came home from Athens, GA this weekend (with our 1 year old grandson, Emerson!) and we finally had time to do this. It was an interesting fitting, and I thought some of you might like to hear some of the particulars about this one.

David hits the ball a mile, but not always straight. His primary interest in getting a new driver was not in obtaining more distance but in getting more consistency - hitting more fairways.

His present driver is a Cleveland Launcher 8.5 degree loft, 46 inch length. It has a Fijikura Launcher Gold 65 S flex shaft.

I first measured David's wrist to floor distance - it is 37-1/2 inches. Based on some correlations that I have from publications by Tom Wishon (33 years in the clubfitting and clubmaking business and one of the premier golf club designers) a first estimate of the correct driver length for David is 44-1/4 inches long - a lot shorter than the driver length he is presently playing.

I then made some measurements of his hand size to get an initial idea of the size of grip that would work well for him. He has the biggest hands I have yet measured in a golfer - the distance from his life line to the tip of his middle finger is about 9-3/8 inches. This is about an inch longer than the longest measurement I previously made for other golfers. My initial estimate is that he should be playing in grips that are at least 1/16 inch in diameter over the men's standard size. I asked him to grip his present driver, and it was clear that the size of this grip was approximately men's standard, much too small for him.

I then took some video of his golf swing (all of the fitting was done indoors at the Centenial Teaching/Fitting Facility). Based on looking at slow motion of his swing using his present driver, I found that his "tempo time" - from start of his swing to ball impact - was about 1 second, and that he "released" his wrist cock at about an 8 o'clock position (for comparison Tiger releases at about 6 o'clock, right at the ball location).

We then did testing to identify the driver length that David would hit most consistently in the center of the club. We did "impact label" testing with three different driver lengths - 44, 44-1/2, and 45 inch lengths - these tests were done with one driver head and three different shafts that could be attached to the head using the Club Conex "FAZ FIT" connector system. All of the test drivers had approximately the same D3 swingweight. The results were very clear - David hit EVERY shot in the middle of the clubface with the 44 inch driver, and the results with the other lengths were no where near as good as for the 44 inch length.

We then collected driver performance data using the Zelocity Launch Monitor. We did tests with David's present driver and with 5 other test drivers; all tests were done with the same test shaft and by adding weight (lead tape) to the head to make all test driver swingweights be approximately D3. David's average swing speed was about 116 mph (wow, what can I say....). The spin rate for the majority of his test shots was typically less than 3,000 rpm, a good range to be in but there is room for improvement by reducing ball spin.

The main purpose of the driver head testing was to identify if there was one head that produced significantly better performance results and that felt the best to David. One head did in fact provide better overall results - lower spin, slightly longer carry distance, and higher "power transfer ratio" - the ratio of ball speed to swing speed. However, David did not like the overall look of this driver head, and so the slightly better performance results were not as important to him.

The driver head that we finally decided on based on the performance testing was the Wishon 919 THI head. The test head that he hit was actually a bit higher in loft than the other test heads - 11 degrees compared to 9 degrees for the other heads - but overall performance results were comparable to those achieved with other test heads. And this particular head is one that has a high clubhead moment of intertia (MOI) and so is more forgiving of off center contact - again, remember David's desire to get more consistency in hitting fairways.

I then did some additional analyis of David's launch monitor test results to show him where there are some areas where he could improve his driving distance - in particular, lowering driver spin rate and increasing launch angle.

I used a shaft fitting program developed by Jerry Hoefling Sr. - a well respected AGCP clubfitter. Jerry's "BMT" software - butt, middle, tip - was used to identify the best candidate shaft for David's new driver. This software has a database of many available shafts where flex profiles have been measured to determine shaft butt, middle, and tip flexes. The program allows me to input the measured driver swing speed, swing tempo, and release point and choose a shaft that will be the best fit for David's swing. The shaft that is the best fit for him is the Aldila VS Proto "By You" shaft.

The final result of the fitting is that I will build David a Wishon 919THI 9.5 degree driver, 0 degree closed face, 44 inches long, with a Aldila VS Proto S shaft, and will build this to a final D3 swingweight. I will use an Midsize Star Grip that I will build up to slightly over 1/16 inch diameter over men's standard size.

And I hope that he does not use this new driver to beat his dear old dad in golf yet.....but if he beats his father in law, well what can I say!!


Tony