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Lihu

DIY MOI matching

35 posts in this topic

Here is the post that got me started thinking about this: http://thesandtrap.com/t/70872/bogey-golfer-only-thread-handicap-index-from-16-22-what-are-you-going-through-working-on-sob-stories/558#post_936369

More precisely @MS256 got me interested in this topic.

I wrote a little matlab script to estimate the "MOI". I used a basic rod and mass formula. I also googled for the mass of the Mizuno MP32 heads and the KBS shafts/grips and the head/shaft/grip of the driver that I am really comfortable swinging.

From this rough model it looks like I need to add a mass of 57gm to my 3i and increment by 4gms for each club down to the PW. This gives me a ratios that look something like this:

>> mp32

I_ratio =

Columns 1 through 6

1.0007    1.0001    0.9976    0.9991    0.9988    1.0023

Columns 7 through 8

1.0067    0.9979

The first column is the 3i and the last one is the PW and everything in between are columns 2 to 7.

It seems like the feel would be much better than what it is now, which is about a 30% difference in the MOI. This kind of explains why when I got used to the new MOI of the heavy shafted woods the MP32 felt like much lighter.

I would also be hard pressed to ruin my beautiful MP32 my drilling/tapping holes to add Tungsten weights to them, but that would be a more permanent solution. Also, I would need to know where would be the best place to add them. I would need to start a SolidWorks/Pro-e/Ansys model before even considering anything this radical anyway.

So, my questions are many, but here are the first ones. Is this a more or less rough approximation for "MOI matching"? Does this seem accurate enough to start playing with lead strips (which I will probably do anyway)? Where should I add the lead tape? Also, has anyone added the tape to the hosel?

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From this rough model it looks like I need to add a mass of 57gm to my 3i

Am I reading this correctly?  The model stated you needed to add 57 grams?  Where would you add this on the club?

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Quote:

Originally Posted by Lihu

From this rough model it looks like I need to add a mass of 57gm to my 3i

Am I reading this correctly?  The model stated you needed to add 57 grams?  Where would you add this on the club?

That's one of my questions.

It goes up with the shorter clubs. Luckily, lead tape has a pretty small volume for the amount of mass it adds. For reference, my driver has a mass of 135 (shaft) + 202(head) + 59(corded grip) or about 396gms total.

Lead has a density of 11.34 gm/cm^3. So, if the strip were 6cmx2.5cm it would need to be about 3.3mm thick. That would be evenly distributed across the muscle part of the V, I would imagine.

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That's a whole lot of lead tape.... I'm just thinking 57g is what, 2oz of weight? I am interested in learning more about this, love to hear what the clubfitters have to say on the subject.
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http://www.tutelman.com/golf/clubs/MOImatchRecent.php

http://www.tutelman.com/golf/design/swingwt4.php#sw_scale

" Now, here's a somewhat more precise and general guideline:

  • The swingweight should go down by 1.3-1.4 points for every inch the club's overall length increases . That's about one and a third points per inch. This is a little more precise about the slope.
  • If, at some point in the set being matched, you change shaft models so that one is substantially lighter than the other, then add one swingweight point to the target swingweight for each 20 grams the raw, uncut shaft gets lighter ."

From there you can use swing weight math and calculate the amount of lead tape. Since I knew I was getting new clubs, I did this with my old ones. Let me just say, it takes ALOT of lead tape. Especially if your clubs are really off their swing weight.

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http://www.tutelman.com/golf/clubs/MOImatchRecent.php

http://www.tutelman.com/golf/design/swingwt4.php#sw_scale

"Now, here's a somewhat more precise and general guideline:

The swingweight should go down by 1.3-1.4 points for every inch the club's overall length increases. That's about one and a third points per inch. This is a little more precise about the slope.

If, at some point in the set being matched, you change shaft models so that one is substantially lighter than the other, then add one swingweight point to the target swingweight for each 20 grams the raw, uncut shaft gets lighter."

From there you can use swing weight math and calculate the amount of lead tape. Since I knew I was getting new clubs, I did this with my old ones. Let me just say, it takes ALOT of lead tape. Especially if your clubs are really off their swing weight.


Thanks, Saevel. The second link shows that I am at least in the right ballpark, slightly different MOI targets but at least close enough to experiment. I probably need to go to mcmaster to custom make the lead strips and find a suitable adhesive.

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I'm not a club fitter either (by a long shot) and don't even have a swing weight scale. My back yard experimenting is strictly by feel (and certainly not something I would recommend).

A good club fitter would know more about not only how much weight to add but where (and how) to add it.

I have used different kinds of lead tape but I'm not a big fan of the pre-made 6 gram lead strips. They work well enough for experimenting but fly off during use more than I would like.

Some clubs have a very handy spot to put lead tape in a place that's both out of the way and not very noticeable and will stay on the club. My clubs don't have a very good place to put it. I managed to get enough equally distributed and out of sight inside of a well in the back of the cavity on my R7s but when I'm satisfied that I like it I may try something different like adding lead powder down the shaft and plugging it in place. That itself could change the way the club plays because the location of the weight will have changed from equally distributed along the club to the very bottom of the shaft.

There's really a lot to it and backyard experimenting like I do can't match what a club fitter with an MOI machine, and years of know how, can do. I just like tinkering and if I make a mistake it's easy enough to correct.

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I'm not a club fitter either (by a long shot) and don't even have a swing weight scale. My back yard experimenting is strictly by feel (and certainly not something I would recommend).

A good club fitter would know more about not only how much weight to add but where to add it.

I have used different kinds of lead tape but I'm not a big fan of the pre-made 6 gram lead strips. They work well enough for experimenting but fly off during use more than I would like.

Some clubs have a very handy spot to put lead tape in a place that's both out of the way and not very noticeable and will stay on the club. My clubs don't have a very good place to put it. I managed to get enough equally distributed and out of sight inside of a well in the back of the cavity on my R7s but when I'm satisfied that I like it I may try something different like adding lead powder down the shaft and plugging it in place. That itself could change the way the club plays because the location of the weight will have changed from equally distributed along the club to the very bottom of the shaft.

There's really a lot to it and backyard experimenting like I do can't match what a club fitter with an MOI machine, and years of know how, can do. I just like tinkering and if I make a mistake it's easy enough to correct.

That was another thought as well, and a great idea. The lead would run up the shaft about 15cm on the shortest club (worst case). Probably can experiment by placing lead around the shaft near the hosel. I can see a computer model is going to be needed for any further refinement. I am trying to eliminate a gross error of 30% right now, so even this should work better than what I've got.

Thanks again for another great suggestion, I prefer it because the club would still "look" normal.

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That's a whole lot of lead tape.... I'm just thinking 57g is what, 2oz of weight?

I am interested in learning more about this, love to hear what the clubfitters have to say on the subject.


"Don't" its that simple. Unless you are into experimenting due to boredom or cabin fever. The author of the post in another thread mentioned a club fitter had no luck in fitting himself in over 2 hours. as much as I encourage experimentation for knowledge and understanding, any modification to a golf club to be successful also has accompany a repetitive swing. doesn't have to be great but needs to be repetitive.  I am unfamiliar with "WIP" when it comes to a handicap in the OPs profile. Work in progress? Perhaps lessons from your local PGA pro could prove far valuable in the long term than any amount of lead tape on a golf club-with a possible exception of a putter.

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Quote:

Originally Posted by billchao

That's a whole lot of lead tape.... I'm just thinking 57g is what, 2oz of weight?

I am interested in learning more about this, love to hear what the clubfitters have to say on the subject.

"Don't" its that simple. Unless you are into experimenting due to boredom or cabin fever. The author of the post in another thread mentioned a club fitter had no luck in fitting himself in over 2 hours. as much as I encourage experimentation for knowledge and understanding, any modification to a golf club to be successful also has accompany a repetitive swing. doesn't have to be great but needs to be repetitive.  I am unfamiliar with "WIP" when it comes to a handicap in the OPs profile. Work in progress? Perhaps lessons from your local PGA pro could prove far valuable in the long term than any amount of lead tape on a golf club-with a possible exception of a putter.

Yes, my swing is also WIP. Hcp is about 15, and there is still a huge amount of work on my swing to be done.

However, I am hoping that you can also give more insights to MOI matching. Kind of hoping to keep the thread going to other DIY golfers.

BTW, the putter is on the list of things to get heavier.

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"Don't" its that simple. Unless you are into experimenting due to boredom or cabin fever. The author of the post in another thread mentioned a club fitter had no luck in fitting himself in over 2 hours. as much as I encourage experimentation for knowledge and understanding, any modification to a golf club to be successful also has accompany a repetitive swing. doesn't have to be great but needs to be repetitive.  I am unfamiliar with "WIP" when it comes to a handicap in the OPs profile. Work in progress? Perhaps lessons from your local PGA pro could prove far valuable in the long term than any amount of lead tape on a golf club-with a possible exception of a putter.

That's a big part of it for sure. :beer:

Once the weather gets better those things rarely cross my mind and I just play. My clubs do feel awfully good right now when I run out in the backyard and hit them out of the place where I swept the snow away. :dance: And then run back in the house to warm up.

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Yes, my swing is also WIP. Hcp is about 15, and there is still a huge amount of work on my swing to be done.

However, I am hoping that you can also give more insights to MOI matching. Kind of hoping to keep the thread going to other DIY golfers.

BTW, the putter is on the list of things to get heavier.


Based on your profile, handicap of 15, swing still in progress. I believe the real reason why you have a 15 handicap and not lower is: You are using a player club, very tough to hit pure & consistent & used by a much better golfer, you need something with a much larger sweet spot, maybe not a super game improvement club but  something much more forgiving than the MP32s. Your diver has too low of loft and way to heavy and way to stiff shaft......in a nutshell most of your equipment is likely working against you. I am assuming your club head speed is not 110+

So here is a question for you: If you an I were having a match, we are tied and going into the last hole, you are 150 yards out in the fairway hitting to a flat green, no elevation, no wind and the pin is in the exact center. You need to get on the green, 2 putt and you would win the hole and match. With a high probability which iron would you play to ensure getting on the green pin high to ensure the win?    Hint- there is no right or wrong answer.

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That's a big part of it for sure.

Once the weather gets better those things rarely cross my mind and I just play. My clubs do feel awfully good right now when I run out in the backyard and hit them out of the place where I swept the snow away. And then run back in the house to warm up.


But you're in Alabama, try the Midwest or northeast for cold temps!

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Quote:

Originally Posted by Lihu

Yes, my swing is also WIP. Hcp is about 15, and there is still a huge amount of work on my swing to be done.

However, I am hoping that you can also give more insights to MOI matching. Kind of hoping to keep the thread going to other DIY golfers.

BTW, the putter is on the list of things to get heavier.

Based on your profile, handicap of 15, swing still in progress. I believe the real reason why you have a 15 handicap and not lower is: You are using a player club, very tough to hit pure & consistent & used by a much better golfer, you need something with a much larger sweet spot, maybe not a super game improvement club but  something much more forgiving than the MP32s. Your diver has too low of loft and way to heavy and way to stiff shaft......in a nutshell most of your equipment is likely working against you. I am assuming your club head speed is not 110+

So here is a question for you: If you an I were having a match, we are tied and going into the last hole, you are 150 yards out in the fairway hitting to a flat green, no elevation, no wind and the pin is in the exact center. You need to get on the green, 2 putt and you would win the hole and match. With a high probability which iron would you play to ensure getting on the green pin high to ensure the win?    Hint- there is no right or wrong answer.


8i would be my choice, so my swing speed is probably not 110+.

You're right about the player club business, and the driver part. However, I get reasonable distances and the ball goes straighter than with my other setup.

I am also thinking of doing these changes to my Ping I20s, which are way easier to hit. Their stock CFS stiff shaft goes really high even though I put some lag on the shot. I can hear a hiss off a 9i and it goes really high.

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But you're in Alabama, try the Midwest or northeast for cold temps!


One thing I've learned over the years is that cold is cold no matter where you are. When I was working 3rd shift outdoors and 300 feet in the air in northern Missouri there were some guys from Wyoming that came to work there. One by one they all quit and went home, each saying they couldn't take the cold.

When I asked one of them about it he said when it's 0 in Wyoming it's nice and when it's 0 in Missouri it's unbearable. How well people take the cold mostly depends on whether they are outside or not.

BTW. Supposed to be low single digits here tonight. :cry:

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8i would be my choice, so my swing speed is probably not 110+.

You're right about the player club business, and the driver part. However, I get reasonable distances and the ball goes straighter than with my other setup.

I am also thinking of doing these changes to my Ping I20s, which are way easier to hit. Their stock CFS stiff shaft goes really high even though I put some lag on the shot. I can hear a hiss off a 9i and it goes really high.

Hitting it high is fine. Your swing speed is likely 96-102

Irons, steel stiff flex 95-110 gram- nothing elaborate

Hybrid, graghite stiff- 70-80g max

fairways, graphite stiff -70gram max

Driver, graphite stiff 57- < 65g  10+ degree.

Hitting your driver with a steel 100+gram shaft, with a low trajectory, you are lucky to hit 180-200 yards.

Your answer to lower scores is not tinkering with MOI or frequency matching. Its about ball striking!

I saw Jason Day once without any warm up, hit the highest shots I have ever seen with hit 9 iron, it was towering! I am often told I hit a high ball, mine goes 135 yards, his ball looked like it went twice as high and landed closer to 160.

What was further amazing is each club in his bag, with the help of a flightscope launch monitor went the same height ( with a variable of 2+/- yards) The apex height of his ball flight from sand wedge to driver were almost identical, many were identical. just where that apex was in relationship to impact were different, but the height was the same.  He then demonstrated the opposite hitting each club full strength in his bag at about 1/4 the height right thru the bag. Its about ball striking and a repetitive swing not lead tape.

Good luck

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"Don't" its that simple.

Thanks, I wasn't planning on it. I'm interested from an academic standpoint. I don't know much about clubfitting and equipment and I simply meant it was a good opportunity to learn something new

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Quote:

Originally Posted by Lihu

8i would be my choice, so my swing speed is probably not 110+.

You're right about the player club business, and the driver part. However, I get reasonable distances and the ball goes straighter than with my other setup.

I am also thinking of doing these changes to my Ping I20s, which are way easier to hit. Their stock CFS stiff shaft goes really high even though I put some lag on the shot. I can hear a hiss off a 9i and it goes really high.

Hitting it high is fine. Your swing speed is likely 96-102

Irons, steel stiff flex 95-110 gram- nothing elaborate

Hybrid, graghite stiff- 70-80g max

fairways, graphite stiff -70gram max

Driver, graphite stiff 57- < 65g  10+ degree.

Hitting your driver with a steel 100+gram shaft, with a low trajectory, you are lucky to hit 180-200 yards.

Your answer to lower scores is not tinkering with MOI or frequency matching. Its about ball striking!

I saw Jason Day once without any warm up, hit the highest shots I have ever seen with hit 9 iron, it was towering! I am often told I hit a high ball, mine goes 135 yards, his ball looked like it went twice as high and landed closer to 160.

What was further amazing is each club in his bag, with the help of a flightscope launch monitor went the same height ( with a variable of 2+/- yards) The apex height of his ball flight from sand wedge to driver were almost identical, many were identical. just where that apex was in relationship to impact were different, but the height was the same.  He then demonstrated the opposite hitting each club full strength in his bag at about 1/4 the height right thru the bag. Its about ball striking and a repetitive swing not lead tape.

Good luck

So, true about ball striking, and thanks for taking the time to give me this fitting information!

Here's what I observed about my previous setup versus the one I hacked together.

My old Ping G15 10.5 degree with 65gm Stiff  was more or less what you recommended for my driver. The issue I had was a higher dispersion of shots and a much higher ball flight, so that is why I went with my current setup. On the course, I seem to be outhitting my old setup by a good 20 yards or so. More importantly, I find myself on the fairway more often. The extra weight seems to emote much more confidence than the older shaft setup. Not sure why this is the case.

The Ping stock CFS stiff shafts are probably lighter than what you recommend for me, and that might account for the "extra high" ball flight I had with those clubs. I have some old Rifle stiff shafts in the 100 gram range, and might put those on my i20s.

BTW, what is the typical ball height in yards? 30 yards? It would be nice to quantify what we mean by high and a standard flight. Was Jason Day's 9i 30 yards or higher? I ask because when using the ping i20s, I hit higher than any of my playing partners.

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