Aerotech Steelfiber fc115cw X Flex CPM Slope

[laxwax]

I'm building up a new set of irons 4-GW with Aerotech Steelfiber fc115cw shafts. I noticed the CPMs marked on the butt of the shafts, so being the engineer I am, I looked at the slope progression of the CPMs. You can see the data and the slope below. It seems the 7 and 8 iron a little out of whack, with the 7 being soft and the 8 being hard.

 

These are going in parallel heads (Wishon 585PC). So I think I have some options. I could tip the 7i like 3/8" (and still fit in the parallel head) and also maybe install the 8i 1/4" short (since I have 1 1/4" insertion, so I'd still have an 1" insert).

 

Am I over thinking this? Or are my ideas for the 7i and 8i the best I might be able to do to make it better?

 

 

 

 

[Tasals]

those shafts are off what 0.8% and 0.95% from actual to ideal fit? Do you really think youll notice a shaft that is less than 1% off ideal flex? I think youre overthinking it my man. But if you want to be extra, thats fine too I tend to get a bit extra when cooking so who am I to stifle your vision. You have other ways of getting the perfect CPM but I would be a bit worried about having an iron off spec length you might start running into some distance overlaps. You could/need to account for head weights, head weights could vary and throw off the flex of the shafts as well maybe youll get lucky with the head weights and can just use some lead tape or tip weights to adjust the CPM of the shaft, there are some general guide lines out there on how 2g of weight = 1 cpm change.

Edited July 12, 2022 by Tasals

[Thayneil]

1 hour ago, laxwax said:

I'm building up a new set of irons 4-GW with Aerotech Steelfiber fc115cw shafts. I noticed the CPMs marked on the butt of the shafts, so being the engineer I am, I looked at the slope progression of the CPMs. You can see the data and the slope below. It seems the 7 and 8 iron a little out of whack, with the 7 being soft and the 8 being hard.

 

These are going in parallel heads (Wishon 585PC). So I think I have some options. I could tip the 7i like 3/8" (and still fit in the parallel head) and also maybe install the 8i 1/4" short (since I have 1 1/4" insertion, so I'd still have an 1" insert).

 

Am I over thinking this? Or are my ideas for the 7i and 8i the best I might be able to do to make it better?

 

 

 

 

how are the heads?

always been a Wishon fan

[laxwax]

From the raw number of the individual shaft, it might be less than 1%, but if the standard CPM slope is around 8 or 9 CPM from iron to iron, then they are off by more like 30%.

 

Lengths in the table are the raw shaft length, not trimmed shaft length. All shafts will be dry fit then trimmed to my playing length, so playing lengths are not a concern. 

Headweights are not a concern, Wishon heads have an internal hosel port where up to 9 grams can be added to the hosel.

The irons will be MOI matched, so tweaking headweights to affect CPM is not an option, in my mind.

 

I don’t have the ability to measure CPM myself, so all I have is the marking from Aerotech. If I didn’t have it, then I would be in ignorance is bliss mode, but since I have some actionable data, I feel like I need to do something about it. 

[Stuart_G]

9 hours ago, laxwax said:

Am I over thinking this? Or are my ideas for the 7i and 8i the best I might be able to do to make it better?

 

Are you someone who can feel the difference that 3/8" or 1/4" tipping can have on the stiffness feel of the shaft?    Most am's can't tell the difference for a full 1/2" of tipping (or the equivalent of a full soft/hard step).     So for most people it would be overthinking it.   Whether that's the case for you or not, I can't say.

 

 

 

[laxwax]

1 hour ago, Stuart_G said:

 

Are you someone who can feel the difference that 3/8" or 1/4" tipping can have on the stiffness feel of the shaft?    Most am's can't tell the difference for a full 1/2" of tipping (or the equivalent of a full soft/hard step).     So for most people it would be overthinking it.   Whether that's the case for you or not, I can't say.

 

 

 

Thanks Stuart, I probably can’t feel the 1/2 flex, but I have 1 other thought… If it was one shaft out of line, then I probably would be like “eh, whatever, that’s fine”, but I really don’t like that it’s 2 shafts right next to each other that are off with one hard and one soft. I feel like the difference between the 6 and 7 is fine, and the 8 and 9 fine too. But because the 7 is soft and 8 hard I feel like the difference between them being right next to each other is going to be able to be felt and is what is giving me the analysis paralysis.

[Stuart_G]

17 minutes ago, laxwax said:

Thanks Stuart, I probably can’t feel the 1/2 flex, but I have 1 other thought… If it was one shaft out of line, then I probably would be like “eh, whatever, that’s fine”, but I really don’t like that it’s 2 shafts right next to each other that are off with one hard and one soft. I feel like the difference between the 6 and 7 is fine, and the 8 and 9 fine too. But because the 7 is soft and 8 hard I feel like the difference between them being right next to each other is going to be able to be felt and is what is giving me the analysis paralysis.

 

I understand - but that doesn't really make it any more likely you'll notice the difference between "fixing" them or not.   Especially since we really don't know where in the shaft those differences are coming from.

 

On top of that, tip trimming doesn't really have nearly as much of an effect on the butt frequency as steel shafts, so it's less likely that you'll get much of a change in butt freq.

 

Of course, if it's not going to be noticeable, then it probably can't hurt anything either.  Just extra effort with little gain.  

 

I say "probably" because there is not really a direct correlation between butt frequency (and anything you do to it) and how the feel of the shaft might change - particularly in the context of tip trimming.

 

[Thayneil]

1 hour ago, laxwax said:

Thanks Stuart, I probably can’t feel the 1/2 flex, but I have 1 other thought… If it was one shaft out of line, then I probably would be like “eh, whatever, that’s fine”, but I really don’t like that it’s 2 shafts right next to each other that are off with one hard and one soft. I feel like the difference between the 6 and 7 is fine, and the 8 and 9 fine too. But because the 7 is soft and 8 hard I feel like the difference between them being right next to each other is going to be able to be felt and is what is giving me the analysis paralysis.

if you are  particulary concerned  about small difference  be careful that if you do change them you wont be concerned about the  graphics lining  up or  that the 8 iron is short shafted!

 

its a serious point!

[me05501]

Contact Aerotech with your question. I'm sure they be happy to educate you about their specs and if the shafts aren't where they should be they'll replace the ones that are off. Might as well do it before they're built up. Don't give yourself a reason to doubt the clubs after they're built.