[Shaft] International Flex Code

4 numbers indicate flex of each section from tip to butt.
What are brands already using? How accurate are these numbers?
How to make it usefull for us?

Think is too technical for the layman, maybe complicated.
But certainly a good club fitter can make good use of the code...

Miyazaki is the first one to introduce this, its a shaft profiling chart that allows consumers to understand how a shaft will perform.

in this case assuming that the true playable length of the shaft is 43.5 inch (minus distance from ground to hosel), the profiling is done at 11 inch interval. in more detailed profiling it is done at 7 inch interval.

first digit represents butt stiffness
The second digit represents mid butt stiffness
The third digit represents mid tip stiffness
The fourth digit represents tip stiffness

the are 10 digit and it starts from )

0
1 represent A flex
2
3 represent R flex
4
5 represent S flex
6
7 represent X flex
8
9 represent XX flex

the stiffness is measure by flex (bending) and torque (twisting), by using this system one can understand the characteristic of all shafts. in some discussion on professional club fitting forum where independent clubmakers profiled a range of leading golf shafts, it was revealed that the Dromos has an uncanny similarity to the Diamana Blue Board.

relevance for the average golfers:

- in a positive manner - it allows one to have choices based on budget, brand and performance.
- in a negative manner - too much information may not necessarily lead to a better game.

Hope this helps......DGman

PS you can figure out what 5445 or 5544 or 4554 represents.....

thankz DG i was trying to understand my miyazaki shaft


so the normal understanding of shaft ie: shaft frequency is now a more general term ?

my shaft is 4212

Hmm.... think i use the 4 numbers to buy 4D better!

Anyway, thanks DG for the great info.

i would love to dwell further but its information that the most consumers of golf shafts do not get too deep into.

there are terms like vertical oscillation, bow, tip deflection in addition to the usual practice of bending and torsion measurement to further determine how each shaft is profiled.

in Miyazaki case, the nos represent the type of launches that a user can expect. i do not sell Miyazaki hence my lack of knowledge about their nos but i read that Kusala line alone have more than 5 different launches and the C.Kua (39, 43, 59 and 72) range in different weights are all different shafts with very different shaft profiles.

DGman

Thanks DG for great sharing.


I am agree with you Peace...and I believe without proper fitting all those numbers are useless and surely digging into it could lead into expensive experiment. Just my wonder, what is the purpose they are created for? Is it to enhance club fitter decision only? Or it's targeted to user with other way of marketing ploy for exotic shaft? I saw big OEM company start using it on their upgrade shaft.


@Madmaru: looks like you have stiff butt...lol...justkiddin!