3 replies to this topic

[rocket21]

I am have searched forums but am still a little confused. E.g if you extend an iron shaf by 1/2" I know cpm will decrease by 3 cpm, this is due to the increase swing weight, correct?  If I maintain the same SW then the shaft should play the same?

Goal is to get to an equivalent x100 soft stepped 1x at D6 sw can someone confirm this is on target before I start cutting:

1) I will assume that D2 is the baseline at standard length 5 iron of 38" to play true to flex , so if I install straight in (no soft stepping) at 1/2 over standard then I get to d5 and lose .3 cpm.  Now if I add add ~2g tip weight or lead tape to get to d6 I lose another .1 cpm and end up at .4 cpm less in total so Another way of looking at it is the length per se does not matter just its effect on swingweight?
2)if I choose to play at standard length then just adding ~ 8 grams to get to D6 should play at -.4 cpm as well.
3) lastly if I play the 4/5 irons only at d4 will they play noticeable stiffer and does anyone else do this with the lower lofted irons?  Thanks.

Edited by rocket21, 03 January 2013 - 11:39 PM.

[NRJyzr]

If you're using DG shafts, changing length will do nothing to the flex.  The cpms will change, but they will follow along the flex slope, keeping the shaft at the same flex.

The longer version is....  by going longer with the club, you will have increased swingweight 3 cpm, which will soften the club on a 1cpm per 1 swingweight point basis.

However, the butt section is the stiffest part of the shaft.  Adding butt section stiffens the shaft.  As it happens, with DG, the effect is nearly identical to the effect of the added swingweight, thereby keeping the flex the same.  

Which answers the below item #1.

Quote

1) I will assume that D2 is the baseline at standard length 5 iron of 38" to play true to flex , so if I install straight in (no soft stepping) at 1/2 over standard then I get to d5 and lose .3 cpm.  Now if I add add ~2g tip weight or lead tape to get to d6 I lose another .1 cpm and end up at .4 cpm less in total so Another way of looking at it is the length per se does not matter just its effect on swingweight?

Then, for #2

Quote

2)if I choose to play at standard length then just adding ~ 8 grams to get to D6 should play at -.4 cpm as well.

You are correct, this would soften the shaft 4 cpm.

Quote

3) lastly if I play the 4/5 irons onky at d4 will they play noticeable stiffer and does anyone else do this with the lower lofted irons?

For #3, I'm assuming you intend to play them at d4 compared to d6 for the rest of them?  You will make them play 2 cpm stiffer than otherwise, I rather doubt you'll feel this.  It's possible, but just not likely.

Edited by NRJyzr, 03 January 2013 - 10:37 PM.

[rocket21]

Thanks for info. To be clear on point 1, when you say "Adding butt section stiffens the shaft" are you saying that if you add butt extension it will stiffen the shaft but if you just cut a blank longer it will not (assuming identical SW)?

[NRJyzr]

rocket21, on 03 January 2013 - 11:37 PM, said:

Thanks for info. To be clear on point 1, when you say "Adding butt section stiffens the shaft" are you saying that if you add butt extension it will stiffen the shaft but if you just cut a blank longer it will not (assuming identical SW)?

The "adding butt section" isn't really meant to imply extensions, but just leaving the shaft longer by not cutting as much from the butt end of the shaft.

In other words, doesn't matter HOW you have more of the butt section of the shaft, just that you have more.