In the clubs building / matching process it is necessary to estimate a value of the swingweight before a club is assembled. Such calculation allows proper planning and to select the right components for the designed club.
- desired length of the club,
- weight of the head, and the grip,
- weight and length of the uncut (raw) shaft.
Some fields of calculator contain the default data. These values can be modified if you consider to use heavy ferrule or adapter, bore-through club heads (small BBGM) or more layers of the grip tape. In most cases the difference between results of calculations doesn’t exceed one swingweight point, but not always. The impact of tip trimming is usually negligible and it could be ignored.
The picture below shows how to measure BBGM.
Please remember that the result the calculation is only an approximation. Many factors determine the exact value of the swingweight. It depends of influences of weight distribution of weight in the shaft, the center of gravity in the head, the lie angle of the head, additional layers of the grip tape, weight of epoxy used for assembling the head etc. It is highly recommended to measure the swingweight of the assembled club. Then apply a necessary adjustment if it is needed. Very useful is measurement of the temporarily (provisionally) assembled club.
update: October 2021