Friday, April 30, 2010

TRUE Education on Shaft Frequency Measurement



QUESTION: Hi Mark,

I am a small club builder working out of my garage and I am interested in
putting a Nippon steel shaft in a Taylor Made Burner Driver. I think a stiff
shaft that produces somewhere in the neighborhood of 260 cycles per minute. Do
you have something near that and how much will it cost?

Thanks, Bob


ANSWER: Hi Bob,

Thanks for sending in your note.

You might consider our NS PRO 950FW Series of premium steel shaft models designed for drivers and fairway metals. These are available exclusively via our Authorized Nippon Shaft Installation Centers. Their contact information is available at www.shaftology.com.

Regarding a shaft that "produces somewhere in the neighborhood of 260 cycles per minute", please let me offer a bit of true clubmaking education.

1) "260 cycles", at first sounds like a very precise stiffness rating, however, in the real world, it represents a huge, wide, expansive, very large range of stiffness ratings.

2) What is required is some background info to achieve a more precise language and thus a more precise rating.

3) Because of the variability of the frequency meter machine and its shaft clamp, clamp pressure, base, head weight, grip on or off, etc., and even technician, a given rating, say 260CPM, can represent a stiffness rating of a Senior Flex, Medium Flex, Stiff Flex, or Extra Stiff Flex, or any of the in-between sub-flexes.

4) Because a frequency machine is measuring the "butt frequency" or relative butt stiffness of a given shaft, and not the TOTALITY of how a shaft will play with regards to flex or stiffness, a 260 CPM can represent a stiffness rating of a Senior Flex, Medium Flex, Stiff Flex, or an Extra-Stiff Flex, or any of the inbetween sub-flexes.

5) These variations occur because, for example, some models are very stiff in the butt section, but then very flexible in the mid and tip sections, versus a model that is very stiff in the butt section, and then very stiff in the mid and tip sections. This results in a similar stiffness CPM "rating", but is not at all representative of the stiffness "playability" of the two shaft models.

6)If you realize now the number variations that are in play, you understand that "260 CPMs" is only a raw rating of a given machine, a given measurement methodology, and a given shaft.

7) The next realization therefore, is that comparing this raw number to another raw number, derived from a different machine, different measurement methodology, and different shaft geometry offers no value in comparison.

8) So what is the value of these measurements? My best recommendation is to use a frequency machine and the raw values to compare and evaluate the relative stiffness of one series of shaft models.

9) For example-

Let's say you have an NS PRO 950FW 'S' flex shaft installed in your driver, with specifications of 44" length, D2 swingweight, a standard Lamkin Crossline grip, and the raw frequency value is 260. And let's say that you play with this combination and it feels too flexible, you have a hard time adjusting to the flex, and thus your shot pattern and face contact is erratic.

Next, you have an NS PRO 950FW 'X' flex shaft installed into your same driver, with the exact same specifications, and the raw frequency value is 272. We know that this raw frequency number is of great comparison value since we are using the same machine, same measurement methodology, and same shaft geometry, thus the difference in the CPM value is a direct representation of the actual flex value as compared to the previous club.

Let's say this club feels too stiff, and plays quite "dead", meaning that they only way to get this shaft to play OK is to swing in a jerking motion to get the shaft to flex and thus feel like there is some life to it.

If the stiff club played approximately a half of a flex too flexible, and the x-stiff club played approximately a half of a flex too stiff, and the other specifications of length and weight seemed optimal, then it would be accurate to assume that building a driver with a raw flex value of 266, to the same specifications, would perform excellent.

10) Many newer clubmakers want a simple, one factor, "take my temperature to diagnose my health" approach, to shaft selection, but what is required for best performance and most enjoyment, is a blend of the art and the science of clubmaking.

Regarding the cost of the NS PRO 950FW shaft series, please contact any of our Authorized Centers. The pricing is certainly dependent upon the fitting and installation services offered.

Best regards, Mark