MOI matching. What do you do if...?

[Golfrnut]

Just a hypothetical question...but based on my real world experience.

 

What do you do if you attempt to MOI match a set of clubs through SW progression with CW shafts, but, the short irons end up feeling to head heavy(off balance) and the long irons end up too light where the person has trouble gaining a sense of the head in the downswing?

 

Revert back to SW matching? Just interested to hear some thoughts/opinions.

[Howard_Jones]

Just a hypothetical question...but based on my real world experience.

 

What do you do if you attempt to MOI match a set of clubs through SW progression with CW shafts, but, the short irons end up feeling to head heavy(off balance) and the long irons end up too light where the person has trouble gaining a sense of the head in the downswing?

 

Revert back to SW matching? Just interested to hear some thoughts/opinions.

 

That would not happen real life, IF you had total weight under control.

Using CW shafts will sometime give us to little head weight in the long, compared to feedback of shaft weight,, but that tells us we missed out on total weight target, so we should go down on shaft weight to be able to get feel of head weight "in balance".to the shaft.

 

We can NOT get it right by MOI or Progressive SW alone, Total weight is always #2, balance is only #3 on that list, so if "matching" of Moi turnes out wrong in one or both ends, its a question of Total weight, and in this case by using to high shaft weight.

[Howard_Jones]

Look at this examples of using a 110 vs a 130 gram shaft.

Look at how the % of each component changes, and how total weight might vary even with the same MOI or SW

 

We start out with a difference of 20 grams, but can get it down to 2 grams on total weight difference, but there is also options between using a shaft above 110 grams or below 130

 

Thats why i say, Start with the GRIP, its a contributor to total weight, so get grip weight in as it needs to be from the start, then you dont miss on shaft weight or total weight that easy as many does.

 

 

 

 

 

This chart shows how this components makes a difference to Club balance (Danish language, but you get it)

 

 

[Golfrnut]

Interesting points Howard.

 

I'll be back in the morning to revisit this after some sleep. I'm too brain dead to read those charts at the moment. ;)

[Howard_Jones]

Interesting points Howard.

 

I'll be back in the morning to revisit this after some sleep. I'm too brain dead to read those charts at the moment. ;)

 

Its very simple really, just look at row 1 using a standard grip, and standard Head weight

If we used DGX 100 vs a 75 grams shaft, we start out from a total weight difference of 50 grams

If we for the sake of ease say 9 grams shaft weight is 1 SWP we need 2x5 grams on that 75 grams shaft club head to get the same resistance. Total weight will still be 40 grams apart.....not the same club.

 

Again, start with grip weight, and keep total weight under control, MOi or SW alone cant do much with that, so never forget Total weight.

[Golfrnut]

No worries, I just wanted to be able to fully digest what you were saying in both your posts.

 

You are basically just referencing going back to the MBI theory using progressive shaft weighting correct? Keeping the shaft weight the same in the short irons and going lighter in the long?

[Howard_Jones]

No worries, I just wanted to be able to fully digest what you were saying in both your posts.

 

You are basically just referencing going back to the MBI theory using progressive shaft weighting correct? Keeping the shaft weight the same in the short irons and going lighter in the long?

 

Both shaft weight and head weight should be progressive if possible, but that option has not been common for irons until lately, so when using descending weight in irons we should either sort them very good so we start from ascending weight slope as uncut , and/ or use a different length progression where this "misfit" dont show up like it can when it is at its worse like a classic set 3-PW with a sledge hammer 3 iron and no feel of shaft weight left when we get to the PW

 

For a few years ive used a chart with a uncut weight progression of 5 gram pr. inch.

Ive found that to work very good as a guide line (True Temper AMT is 6 grams pr. inch).

My chart is based on uncut weight in a length of 46" for woods, and 41" for hybrids - irons is Constant weight

(makes a difference to grams pr inch cut to play length).

 

Its not very common to end up with a hole bag where shaft weight is off by more than plus 5 gram to minus 5 grams from the suggested shaft weight for the actual club. Just remember that Length and Weight goes together, so if you play the actual club to a different length than the one specified in my chart, you should recalk shaft weight up or down by 5 grams pr inch (2.5 grams at 4/8 or 1.25 grams at 2/8) The chart was made long before TT AMT saw the day of light, so a set AMT irons would have been put in-between 123-127 gram and 127-131 grams iron shaft. (corresponding driver at 43.75 = 65-70 grams, and at 45.00" 60-65 grams)

 

 

[Golfrnut]

I'm with ya....

 

Just one of those desires where it would be nice to have more of a selection of ascending weight shafts to choose from. Perhaps down the road, DG expands on their AMT line to include lower starting/ending weights.

 

Current shafts are 106g. I have been through two other shaft weights in the long irons, 97 & 95 gram. Didn't really notice a change, although I'm sure the MOI is closer to the shorter irons. Impact feel wasn't quite what I was looking for, although not terrible by any means. I am still currently testing the lighter weight in the 4 & 5 irons, time will tell if I stay there or not.

[50jay]

@Howard_Jones Considering graphite is a good option to lower total weight while still maintaining a playable swingweight. What do you think of the Accra line of iron shafts? From what I understand I should be using heavier shafts in the shorter irons to make-up for the shorter length. Would it be a good idea to mix 3 shaft weight throughout the set or it would be overly complicated ? (i.e. 80g for 4-6, 90g for 7-9, 100g for wedges)
Thank you very much
JL

[Howard_Jones]

I hope you started the reading from the top, and understood that total weight is more important than MOI, so dont go for a total weight you never tried, always build a test club.
I dont know ACCRA shafts, they are not a True Temper product, but @WristySwing knows ACCRA shafts well, so he is the right one to ask about them.
Yes we can mix shaft models, just think of the old RIFLE FCM Flighted and Project X Flighted who actually is a MIX of shaft blanks, but in both cases, "VERY Descending weight", since the long irons actually is Soft stepped from half a flex stronger, and short irons actually is hard stepped from a flex softer. As a sum, flex becomes more or less the same for both long, mid and short end, while we change flight pat tern against higher launch in the long end, and lower launch in the short end. The latest RIFLE FCM model is using the same shaft blank for all irons, but a altered tip trim and flex progression slope from club to club...
SO, if you get more insight about this ACCRA shafts mentioned like EI profiles or zone flexes, it easier to see where we go building a set like that. Far from all model is "progressive" like RIFLE FCM and Project X is, Dynamic Gold is the School example of that, where R - S - X and TX actually is 4 different EI profiles, but they "act like" a series of shafts thats "progressive"since they are all LOW launch.A Progressive profile like RIFLE FCM where the WHOLE shaft goes "equally stronger" zone by zone from flex model to flex model is steel shafts with progressive thicker shaft walls on the same "model", while DG and some graphite models has a EI profile with quite a few differences. A set of MIXED flexes of DG shaft would feel very strange, while a shaft with a progressive profile like RIFLE FCM will feel more "uniformed" when we mix shaft blanks. Thats why the EI profile of those blanks becomes of interest, both to see where we start from, but also where we go when altering tip trim to get the flex slope we want them to play on. The more specs you can find of them the better.
Ive included a option like that in the version of my METRIC EXCEL VBA app for iron sets where we can pick each shaft in the set fully independent of the others, so a set 3-PW-GW-SW-LW who is 11 clubs gives you 11 shaft options. The issue is access to the datas i mention above, without it, we dont get much out of it...the prototype without this DB was done more than a year go, so your thinking aint new, its been done before, i just dont have the needed datas for those shafts to be able to tell you what you can and should do with them, and you have not told much about how you want them to play either, so there is a few questions who needs a answer before i can help much more than this. Hopefully WristySwing has some specs he can share.
The example from the app shows off a mix of True Temper XP shafts from 95 via 105 to 115 grams where both R and S flex blanks is used.
[img]https://s3.amazonaws.com/golfwrxforums/uploads/J75AZ6I7VF2W/image.png[/img]

[WristySwing]

Hi. I think Accra is probably the only company you could do a mix and match effectively with in graphite. They have a longer parallel section than most (8" in the I-series and 6" in the I-series Tour) so you can really fine-tune the flex and flight on these quite effectively. I would just be a little hesitant about going through 3 weight classes of shafts covering 20g total of weight. The reason AMT or AWT works for some people is they do it incrementally in 2-3g steps per shaft, not large 10g jumps at certain clubs. With this it would be 80g +/- a couple grams due to tolerances and material lost due to cutting, then a jump to 89g in the 7-9 +/- due to what I said, and then a jump to 99g +/-. Also, while it is small you have to take into account that in a parallel set, your shortest irons will always weigh less than your longer ones. Ideally you would weigh the shafts and put the heaviest in the short and the lightest in the long but even in this scenario more often than not the heavier shaft is going to end up being in the longer club and vice versa. Are you okay having potentially a lighter 6i than a 4i in total shaft weight? Some people are, some aren't. My boss really dislikes doing it for people who are over a certain swing speed -- I personally have done it and don't see a big deal about it and thought it felt great in my irons because I never really felt a "kick" with my wedges and short irons before and finally did going that way.
Another thing to consider is you have an I-Series and I-series Tour model. The I-series tour have a material weave in the butt section and a ti-mesh material to the tip area to increase stability and restrict inconsistent delivery as much as they can. You will be dealing with a lower and slightly reduced spin ball flight and stiffer feel in the butt and tip in the mid irons and wedges. Again, something that only you can really answer if that is right for you or not. Personally I would do as @Howard_Jones suggests and not opt for a weight you have never tried before. You might be better off stick to the 80i in the irons just as well as you might be better sticking to the 110i Tour in the irons. All of them can be tipped and prepped to create a flighted design anyways, so you might not need to go with the weight jumps. I have been fitting with Accra for 2.5 years now and I have never had anyone go this route. I might fit someone for say 70g in the hybrids, 80i in the irons, and then 90 or 100i in the wedges to keep the flow and feel consistent through the set. I have never mixed and matched different weights throughout a set though. It doesn't mean it is wrong, I just don't have experience doing it outside of the already pre-built AMT True Sports models.
If you do want to do it I would suggest you try with a 6i, 9i, Lw then you can get a feel for the lightest and theoretically the stiffest of the models. See if ball flight looks good to slightly a hair low then you will know if the slightly heavier and theoretically softer and higher flights will be better for you to blend in.

[Howard_Jones]

@WristySwing said:

"The reason AMT or AWT works for some people is they do it incrementally in 2-3g steps per shaft, not large 10g jumps at certain clubs. With this it would be 80g +/- a couple grams due to tolerances and material lost due to cutting, then a jump to 89g in the 7-9 +/- due to what I said, and then a jump to 99g +/-. Also, while it is small you have to take into account that in a parallel set, your shortest irons will always weigh less than your longer ones."

Not always, that depends on weight tolerances of the actual model and weight sorting before the set is made. I play a Descending wgt Graphite model myself where weight tolerances was high enough to make a set 5-PW as "Constant weight" with 4/8" between clubs, and we also have some improvement to get if we use a shorter play lenght between clubs than standard. Even a old classic like Dynamic Gold X100 can be modified to Flighted Ascending Weight by combining Soft stepping, tip trim on tapers and 3/8" between clubs. They will only be about minus 0.9 grams down in weight pr shaft, as Ascending weight, but its possible to do it if we like.

We are often way to "conservative", changes takes time, so hybrids was not bagged by all over night, but they are todays norm in the long end, combined with a different and lighter shaft than we play in irons, Some players uses their irons as 3 sets of clubs, like "Long" - "Mid" and "Short" juts like the former "flighted sets" mentioned was, so i see nothing wrong about doing this, but we should be aware of the effects of what we do, so to build test clubs from both ends before a full set is the absolute best. (shortest and longest clubs planned.) The OP will instantly know if clubs with that large a shaft weight difference will work as a set for him or not.

[WristySwing]

I was referring to the Accra stuff where typically the tolerances are +/- 1.5g I have seen and some very rare outliers of being about 2.5-3g out. This typically means in my shop that the amount of trimming required takes off more than the weight variance typically yields. Obviously it does vary some but this is generally true.

[Howard_Jones]

Thats also "good to know" about shaft models, what actual tolerances is seen, official specs is always off some, and it goes both ways, the question is how much...ACCRA iron shafts is 41 uncut.

80 grams / 41.00" = 1.95 grams pr inch, so a set of irons with 4/8" between clubs, would be Descending wgt with half of that or 0.97 equal to 1 grams lighter pr iron shorter.

90 grams / 41.00" = 2.19 grams pr inch, or 1.1 grams "lost" from club to club in a decending wgt set.

100 gr / 41.00" = 2.43 gr. inch / 1.22 gr. lost from club to club.....

By taking advantage of weight tolerances, we can avoid this.

If the shafts we have at hand for a set LONG - MID and SHORT irons, each or 3 shafts, we only need a "tolerance" of 2.0 to 2.5 grams from the longest to the shortest (withing each group of shafts) to make them "constant wgt". If weight tolerance is larger, we go against ASCENDING with the right weight sorting before we build.

The right online shop will offer a weight pick service to get set where we avoid 3 groups of Descending wgt shafts.

Use the tolerances there is in grip weight to even out total weight progression from club to club.

[50jay]

@WristySwing & Howard, Thank you for your help and lengthy explanations. Unpon further research, I found out that Accra offers a "constant" weight option to their iSeries, called the iCWT. Blank length goes from 37" in the wedge all the way to 41" in the 2 iron, in 0.5" increments. From all the info I gathered, Howard usually recommend going with 3/8" increments between each iron, but he mentioned that a 1/2" progression could be done.
Considering I'd like to play my irons 1/2" longer (37.5" 7iron), should I go the 90g iCWT route or experiment with the standard iSeries and weight sort them myself?
Thank you very much.
JL

[WristySwing]

The iCWT is a discrete length parallel tip shaft. It is very unique but allows for basically what you want to do with out having to fart around too much with weight sorting. You can simply just soft-trim the long and hard-trim the short irons to achieve the flight you want. Just be mindful that the Accra Tour series plays super stout to flex, IMO. I had a set of iCWT 105s last year and they were basically unplayable they were so stiff. Easily felt like a C-Taper or PX 6.0 to me even though they are softer at the butt than either of these two so it will CPM soft, it is equal in EI stiffness to both in the mid and tip. I would imagine the 95 is going to be similar to a C-Taper Lite or PX 5.5