Soft and Hard stepping

[BC MIST]

A philosophical question. In a 3 to AW set of 9 irons, the frequency difference between successive clubs is 4.5 cpm's, making the AW 36 cpm's stiffer than the 3. According to the above, 12 cpm's constitute a flex range, therefore, the AW is 3 flex ranges stiffer than the 3. And yet, all the clubs in this set could be classified as a "REGULAR". Why?

In my non-traditional mind, all clubs that have the SAME frequency, should have the SAME classification and so are matched. A set of clubs with different frequencies should have a different classification label as they are mismatched, but at least they are mismatched consistently.

We also know that the tip stiffness is a factor in trajectory, so NOT trimming from the tip should allow the flexing forward of the shaft through impact to be more consistent with the loft of the club influencing the trajectory difference the most. However, if you tip trim, the stiffer tip of the shaft tends to decrease the trajectory. Thus, even though there should be a consistent loft difference to make a consistent difference in trajectory, when one adds the increasingly stiffer tip to the equation, should this not make the successive trajectory's inconsistent? Perhaps this is accomodated by having the centre of gravity of each successive club head fractionally lower than the preceeding one

[rhh7]

A philosophical question. In a 3 to AW set of 9 irons, the frequency difference between successive clubs is 4.5 cpm's, making the AW 36 cpm's stiffer than the 3. According to the above, 12 cpm's constitute a flex range, therefore, the AW is 3 flex ranges stiffer than the 3. And yet, all the clubs in this set could be classified as a "REGULAR". Why?

In my non-traditional mind, all clubs that have the SAME frequency, should have the SAME classification and so are matched. A set of clubs with different frequencies should have a different classification label as they are mismatched, but at least they are mismatched consistently.

We also know that the tip stiffness is a factor in trajectory, so NOT trimming from the tip should allow the flexing forward of the shaft through impact to be more consistent with the loft of the club influencing the trajectory difference the most. However, if you tip trim, the stiffer tip of the shaft tends to decrease the trajectory. Thus, even though there should be a consistent loft difference to make a consistent difference in trajectory, when one adds the increasingly stiffer tip to the equation, should this not make the successive trajectory's inconsistent? Perhaps this is accomodated by having the centre of gravity of each successive club head fractionally lower than the preceeding one

I agree with this, so I am going to build my new set of irons with no tip trimming whatsoever, only butt trim to length.

[Weirfan]

I agree with this, so I am going to build my new set of irons with no tip trimming whatsoever, only butt trim to length.

there is no reason why you cannot do this....clubfitters change the slope al the time.

I have done butt trim only on several occasions, mostly with thick walled grapite shafts and slower ss golfers.....and some shafts are designed as such...butt trim only ....like the Apollo Hump....

whether it works for you really depends on your needs and the shafts

when people are in doubt the best method is to find the amount of trim that works best for you for the shortest and longest irons in your set....then trim the irons in between to that slope. it is more work but the bst

good luck and let us know how it works

[Started2k3]

Maybe one of you guys could answer this.

According to the formula (see Tutelman's or Kaufmann's sites for full formula) doesn't tip trimming have a dispropotional effect on frequency measurements along the shaft?

This is what I have noted.
Partial derivative (note I have converted to %):
%f = -3/2*%L

So a 0.5" tip trim will increase the tip section frequency by 7.5% (measured initially at 10") and at the butt section by 2.4% (measured initially at 31"). Likewise, 1.0" tip trim --> 15% increase at 10" measurement and 4.8% at butt.

So although a hard/soft stepped shaft may have very little stiffness/softness change in butt section, the tip section would be quite a bit stiffer/softer. This increase in the tip section could be more than a "flex" (depending on the initial flex of the shaft).

Is this correct?

[Weirfan]

Maybe one of you guys could answer this.

According to the formula (see Tutelman's or Kaufmann's sites for full formula) doesn't tip trimming have a dispropotional effect on frequency measurements along the shaft?

This is what I have noted.
Partial derivative (note I have converted to %):
%f = -3/2*%L

So a 0.5" tip trim will increase the tip section frequency by 7.5% (measured initially at 10") and at the butt section by 2.4% (measured initially at 31"). Likewise, 1.0" tip trim --> 15% increase at 10" measurement and 4.8% at butt.

So although a hard/soft stepped shaft may have very little stiffness/softness change in butt section, the tip section would be quite a bit stiffer/softer. This increase in the tip section could be more than a "flex" (depending on the initial flex of the shaft).

Is this correct?

If you consider that in all most all steel shafts the thinnest part is the tip and the shaft gets thicker as you move towards the butt....this makes sense...I cannot substantiate the exact quantification of change but,,,,yes you would have a more proportionate increase in tip stiffness versus butt stiffness as you shorten the beam length for your frequency measurement.

[Started2k3]

If you consider that in all most all steel shafts the thinnest part is the tip and the shaft gets thicker as you move towards the butt....this makes sense...I cannot substantiate the exact quantification of change but,,,,yes you would have a more proportionate increase in tip stiffness versus butt stiffness as you shorten the beam length for your frequency measurement.

Why not just run an experiment?

Do a Wishon style frequency profile (measurements at 30", 25", 20", 15", 10" from tip).
Then tip trim by 0.5".
Then re-profile but taking into account the tip trim so measurements at
29.5", 24.5", 19.5", 14.5", 9.5" from tip (same physical postion on the shaft).

Then see if the relative changes of the measurements are disproportionate. If they are, do they match (or at least come close to) theory?

[Weirfan]

Why not just run an experiment?

Do a Wishon style frequency profile (measurements at 30", 25", 20", 15", 10" from tip).
Then tip trim by 0.5".
Then re-profile but taking into account the tip trim so measurements at
29.5", 24.5", 19.5", 14.5", 9.5" from tip (same physical postion on the shaft).

Then see if the relative changes of the measurements are disproportionate. If they are, do they match (or at least come close to) theory?

shaft profiling is not new nor proprietary to Tom Wishon...the PCS has been doing it for years and it is being done being done all over and data bases are being compiled by ind and groups.....

I do believe that all this information is available and taken into consideration by shaft manufacturers when they rec their shaft tipping guidelines.

It is not theory that a shaft wall is thicker at the butt, but fact....it is not theory that a soft stepping or hardstepping changes the relative flex, but fact.....I am not sure what yiu are getting at???