Information
Information on the Test-Clubs
The Dynamic-Lie-Tests are each conducted with an Iron 9 as well as an Iron 6 (Golfsmith)
or an Iron 5 (Wishon and Maltby).
Please observe the following when manufacturing the Test-Clubs:
1. Heads as in the producible golf club set.
2. Shafts as in the producible golf club set.
3. Tip trim as in the producible golf club set.
4. Grips as in the producible golf club set.
5. Grip width as in the producible golf club set.
6. Head weight or MOI as in the producible golf club set.
Information on Dynamic-Lie-Tests
Every club maker and club fitter is able to conduct Dynamic-Lie-Tests.
It is state-of-the-art to individually
adapt golf clubs with reference to the lie angle.
The following should be observed during testing:
1. Always test with golfing shoes and gloves.
2. Ensure shoe soles and ball on horizontal level.
3. The testing person should perform several drives before testing.
4. Ball on hard board, a layer of carbon paper between ball and board.
5. At least two test drives with each iron.
6. We call the imprint on the sole the contact zone.
7. Contact zone with marker divided by a marker in drive direction is equal to the contact line.
8. In Variant 1: Apply template and read.
9. In Variant 2: Measure distance from sole centre to contact line in mm.
Information on individually matching golf clubs …
An amateur golfer with individually fitted golf clubs is hard to find as it is still impossible to directly manufacture golf clubs with these properties. Two current discoveries could now make this possible: the direct manufacture of individually fitted golf clubs without having to elaborately adjust
them to the golfer after production either by bending the hosel or lengthening or shortening the shafts.
Because a golf club, which individually fits a golfer (Abb.2+5+8), must comply with the following conditions apart from numerous self-speaking and previously specified properties: at the moment of impact the sole of the club head must touch the exact centre of the ground (Abb.2) to prevent
any otherwise inevitable pushing (Abb. 1) or pulling (Abb.3).
The importance of central sole contact at the moment of impact for tour players is displayed by the frequent, sometimes daily checking and, if required, the follow-up adjustment of clubs with club fitters or by expert supporters. However, although the club head speed of amateurs is not nearly
as high as that of playing pro's, the Lie-angle can sometimes be shifted, especially by a very hard hit against a stone, so that the club no longer fits.
The root of all problems in the manufacture of individually fitted golf clubs lies in the specific behaviour of the club head at the moment of impact. The ‘Toe down type bending’, the typical forwards curling up of the sole tip with parallel forward buckling of the shaft increases the
Lie angle for the short irons, in some cases by more than 10° (Abb. 10+ 11) and is different
for all golfers and cannot be established in advance or even calculated, for example for producing individual tailor-made golf clubs.
However, it can only be determined whether a golf club really fits individually or not, that is to say whether it meets the condition described above of centrally meeting the sole on the ground when striking the ball, by using a so-called Dynamic-Lie-Test, (Abb. 11) a state-of-the-art process
for determining the soles' lines of contact on a test board, preferably by an expert club fitter. Therefore it takes little imagination to realise that most golfers only seldom or even never subject their clubs to this procedure and we can therefore establish that most golf amateurs do not
play with individual, matching golf clubs (Abb.4+6+7+9).
The impossible is also expected from the metal used to manufacture golf club heads. On the one hand it must be pliable to
enable adjustment in the first place. On the other hand the club head may not shift during a hard drive, which means it should not bend. A further problem is that a golf club, transformed into an individually fitted golf club by severe bending of the hosel, may more or less shift by itself,
so will no longer touch the ground at the exact centre at the moment of impact and can thus no longer be considered fitted.
The first discovery concerns the contact zones or lines of contact created on the sole of the club head
during a Dynamic-Lie-Test. According to state-of-the-art technology, these lines of contact should have the same distances when the so-called WIM, Wrist-to-Floor at Impact, is changed (Abb. 11), i.e. the same values at the moment of impact. We assume that when the WIM is changed
by 0.5 inches, the lines of contact shift by 0.25 inches, namely whilst the WIM increases towards the heel and decreases towards the toe.
However, the matter of equal distances cannot be maintained as such. In fact, the distances are determined by the "sole radii". These sole radii would have to meet in a common central point with equidistant lines of contact on one level and this is only rarely the case. By the way, the
distances are easy to measure using the correct device. Although the author has measured the lines of contact for numerous club heads from various manufacturers during the past years whilst changing the WIM values, he has not yet come across even remotely similar distances of the lines of contact
at all as assumed by state-of-the-art technology.
The above-named measuring values for the lines of contact are now entered in a table and transferred to a template. After a Dynamic-Lie-Test, this template is placed on the sole and enables the determination of the correct golf club length, namely the length with which the tested golf club
would touch the ground exactly centrally. Thus an ingenious process of producing a genuinely fitting golf club, without having to make it fit later by bending it, for example.
Normally, a golfer plays using 8 to 10 irons, that is to say clubs produced using from malleable metal. It would remain
quite an effort to use the new procedure with templates for every club as described in the previous paragraph, although this procedure would be far less elaborate than the globally applied state-of-the art Dynamic-Lie-Testing procedure with erroneously assumed identical distances on the sole
in order to produce individually fitting golf clubs. It would also be simpler and safer, as bending could be performed with readable values and not only with specification of the bendable direction.
According to state-of-the-art technology, identical changes to the Lie value distances are also assumed in case of changes to the WIM values, that is to say 1° lie for changes of the contact line distance on the sole per 0.25 inches when the WIM changes by 0.5 inches. Not only can this assumption
not be maintained, it is also completely wrong, something that could be displayed with a basic knowledge in geometry. So we are once more faced with some very irregular distances, which are reduced as the club lengths increase.
Using the knowledge from the two discoveries on the unequal distances in the case of the sole radii and the lie values, a club size table can be calculated, created according to the LLR-principle based on Dynamic-Lie-Tests with only two Test-Clubs and subsequent
measurement of the soles using corresponding templates (Variant 1) or Measure distance from sole centre to contact line (Variant 2) by interpolation of the length differences with the two golf club lengths and the lie angle of an iron club set. This could be described as individually fitting
for the golfer without any shadow of a doubt whatsoever. It is advisable to perform this interpolation
on screen, so that the result can be printed out.
The results from two Dynamic-Lie-Test would also be sufficient for the golf club industry and especially the club makers, in order to
individually manufacture and supply their popular, proven golf club series for every interested golfer.
