fitting and building moi matched golf clubs

FITTING AND BUILDING MOI MATCHED GOLF CLUBS MATT MOHI TOM WISHON GOLF TECHNOLOGY ©2009 What is MOI?   MOI is a measurement of how much force it takes to put an object into a rotaKonal moKon about a defined axis of rotaKon. How does MOI relate to Golf?   Many might be familiar with a “high MOI” driver head. This is the MOI of the head about it’s Center of Gravity   The MOI we are addressing here is the MOI of the enKre golf club over its full length, as it is set in moKon to rotate about the axis of the wrist cock release in the golf swing. What are we trying to achieve in and MOI Matched set?   Consistency of the weight to length feel from club to club, throughout the set.   Clubs will require the same amount of force to swing and square, so the golfer can achieve a higher level of swing Kming consistency resulKng in more consistent ball flight. Why is MOI Superior to Swingweight?   MOI is a dynamic measurement of the “load” the golf club puts on the golfer where swingweight is simply a raKo of the weight of a golf club based on a fulcrum point on a scale.   Any weight added to a club will raise the MOI and put more load on the golfer. With swingweight measurements, any weight put on the grip side of the fulcrum point will LOWER the Swingweight, but will not lower the amount of effort it takes the golfer to swing the club. How does MOI compare to SW?   If we take an MOI matched set and measure all the clubs on a swingweight scale, as the clubs become shorter, the swingweight will increase slightly.   For instance, if our MOI Matched 6 iron is at D1, we will likely see a swingweight measurement of around D3 on the PW. Is MOI a replacement for Frequency Matching?   No, it is a replacement swingweight matching   Frequency matching and MOI Matching can be done side by side, just as it can also be done in a swingweight matched set. Who benefits from MOI Matching?   Golfers of all skill levels have shown a preference for MOI matched sets‐from beginners to elite golfers.   When all golf clubs in the set require the same amount of effort to swing and square, the swing technique improvement is much for the less skilled golfer.   Elite Golfers have noted the “sameness” of the swing feel from club to club throughout the set. Who doesn’t benefit from MOI Matching?   The vast majority of golfers express a significant preference for their MOI Matched clubs.   In very rare situaKons, golfers who have a keen sense of feel and advanced technique built around a swingweight matched set of irons prefer swingweight matching. Can MOI matching be done on exisKng golf clubs?   Yes, it can be done, but if the set is already swingweight matched, the only opKon will be to match to the longest club’s MOI.   This will require a significant amount of weight to be added to the short irons and will likely result in an MOI that is too high for the golfer.   Also, it has to be assumed that the set is correctly fit for all the other fiang specificaKons for the golfer. Why don’t the big assembled club companies build their clubs MOI matched?   MOI matching works best when a unique MOI is chosen to match well to each individual golfer’s swing moKon and the wide variety of swing moKons and this can only be done when each club is built specifically for an individual golfer and not mass produced to standard specificaKons. Fiang to MOI   It is best to think of MOI Matching as a replacement for swingweight in every way.   MOI determinaKon occurs at the same step within the fiang process as fiang for swingweight. Fiang to MOI Determine proper head, shab, grip, and club length for golfer. (Use the same fiang process as you normally do) 2.  Build a test 6 iron as light as possible based on above parameters. (This creates an MOI “Range” for the golfer based on proper fiang of their equipment to their swing moKon) 3.  Have the golfer hit shots and note the on center contact\ 4.  Obtain golfer feedback about the overall weight feel ad headweight feel of the test club as you add lead tape to the clubhead. 1. 
Fiang to MOI (cont’d) 5. Add lead tape unKl the best on center contact is seen and golfer likes feel/feedback 6. Use the MOI SpeedMatch to measure the club’s MOI. This becomes the build out specificaKon MOI for the rest of clubs in the set. Building to MOI   Same as building swingweight matched set   Dry assemble golf clubs to measure MOI and then make headweight adjustments unKl the deisired MOI is achieved. Building to MOI (Tips and Tricks)   Weight sort shabs so heaviest shabs are used in shortest clubs   Build to 3/8” or 10mm length increment between clubs to make MOI Matching easier   Dry assemble to slightly lower MOI than assembled club to account for tape, epoxy and ferrule (10‐15 MOI points)   Add addiKonal 1/8” Kp trim to achieve frequency slope seen at ½” length increment set   A ¼” change in length roughly equals 40 MOI Points‐
longer increases MOI, shorter lowers MOI Building to MOI (Step by Step) 1. Sort shabs and heads as you would for tradiKonal swingweight built set 2. Measure and mark each shab for Kp trimming. 3. Cut Kp of shabs 4. Install ferrule, insert into head and measure and mark for length 5. Cut bul of shabs to final length Building To MOI (cont’d) 6. Slide on cut grip to simulate weight of grip used on final assembly (Similar weight and shape is OK) 7. Measure MOI of dry assembled club 8. Compare against target MOI and make headweight or length adjustments. 9. Add addiKonal weight if necessary and remeasure. 10. If weight is to be removed and lighter head weights are not an opKon, then a slightly shorter club length will lower total club MOI. (1/4” = 40 MOI points) What consKtutes MOI Matched?   From target MOI, a +/‐ of 10 MOI points is less than a .5% spread   For instance, if the target MOI is 2600, then 2590‐2610 is very acceptable.