Iron swing weight reduction

tannerdc · February 6

So I just got a new set of Mizuno JPX 925 Forged in black w MMT 105S shafts. The specs all came in spot on from Mizuno, except the 7 iron. All the irons are D2, but the 7 iron is a solid D4.

Is there a way to make my 7 iron D2?

Tar_Heel_93 · February 6

8 minutes ago, tannerdc said:

So I just got a new set of Mizuno JPX 925 Forged in black w MMT 105S shafts. The specs all came in spot on from Mizuno, except the 7 iron. All the irons are D2, but the 7 iron is a solid D4.

Is there a way to make my 7 iron D2?

Add approximately 10 grams to the butt of the shaft. I have used brass tip weights to do this. Put a little soap on the tip weight and push it into the hole at the end of the grip. You can also pull the grip and add lead tape to the inside of the shaft. Final and hardest solution is to rebuild the club.

Since they are new I would ask Mizuno to fix the problem.

Good luck.

Stuart_G · February 6

18 hours ago, tannerdc said:

So I just got a new set of Mizuno JPX 925 Forged in black w MMT 105S shafts. The specs all came in spot on from Mizuno, except the 7 iron. All the irons are D2, but the 7 iron is a solid D4.

Is there a way to make my 7 iron D2?

Returning the club is always one possible option (or should be if they have even half decent CS).

Only two valid DIY / local options are:

1) make the club shorter - 2 pts would need to shorten it ~ 3/8"
2) find a way to make the head lighter.
- Pull the head and check for tip weights - they might have messed that up in the factory
- drill material out of the bottom of the hosel.

Forget that nonsense about making the grip/butt heavier to fix a heavy swing weight. Adding weight to something that is too heavy is never a good idea. Swing weight was never designed or intended to work with grip weight changes. You're also more likely to mess up the static weight of the club and the static weight progression of the set trying to do it that way.

One other option is if the D4 isn't really a big problem (how does it actually feel?) and you just want to make sure they all match (which might be more important than the actual value), you can increase the weight of the other clubs in the set to match the 7 iron. It's always easier to add weight to a head than it is to remove it.

Edited February 7 by Stuart_G

is1ander · February 6

30 minutes ago, tannerdc said:

So I just got a new set of Mizuno JPX 925 Forged in black w MMT 105S shafts. The specs all came in spot on from Mizuno, except the 7 iron. All the irons are D2, but the 7 iron is a solid D4.

Is there a way to make my 7 iron D2?

Easiest way is to keep warming up with the 7 iron until you wear away enough metal to get it to D2. JK. Actually, just choke up on it a bit until you adjust to the clubs and eventually you'll forget all about it and start gripping it stock. In fact, the 7 iron may become your favorite club and then you'll want to bump the others to D4.

RSLP · February 6

find the heavier grip in the box, and regrip it...probably get you to 3

Edited February 7 by RSLP
corrected the solution

Nessism · February 6

1 hour ago, RSLP said:

find the lightest grip in the box, and regrip it...probably get you to 3

if you spiral the grip tape using the skinny roll of tape, maybe you could get to the fat side of D2

Didn't you read @Stuart_G post about using grip weight to adjust swingweight?? And BTW, a lighter grip will increase swingweight.

I'd measure length, and assuming spot on, pull the head to see what's going on. That's assuming you don't have a path to just return the club, or set.

RSLP · February 7

4 hours ago, Nessism said:

And BTW, a lighter grip will increase swingweight.

You are correct!

Socrates · February 7

I would take it apart and weigh components. Since these are new, I would send the 7 iron back and let them do it.

evog42 · July 27

I have a similar issue, 7i was 1-1.5 over. Did you get it resolved? My swing weights for my 925 Forged (PX 6.0) came in roughly as follows:

6i D2

7i D3.5

8i D2.5

9i D2

PW D3.5

GW D4

Edited July 27 by evog42

scotts33 · July 27

Just a thought but does anyone test their irons for impact when they either self fit or are fitted by a professional for heft match?

Stuart_G · July 27

1 hour ago, scotts33 said:

Just a thought but does anyone test their irons for impact when they either self fit or are fitted by a professional for heft match?

A lot of people probably don't - but they all should. And not just for heft. It's an important check for fitting: shaft weight, head weight, shaft stiffness, playing length, lie angle and even grip size.

Howard_Jones · July 27

6 hours ago, evog42 said:

I have a similar issue, 7i was 1-1.5 over. Did you get it resolved? My swing weights for my 925 Forged (PX 6.0) came in roughly as follows:

6i D2

7i D3.5

8i D2.5

9i D2

PW D3.5

GW D4

How does your GW, PW and #8 iron feel?
What about the #6 iron?
What about the #9?

If lenght and all other specs is found to be right, and this is how they looks like now, all depending on how the clubs im asking about works for you, there would be 2 different routes to a set that works.

If the GW, PW and #8 iron feels right for you, the #9 feels "light", and the #6 feels a tiny tad heavy, the way to go for you, would be a progressive SW slope with 0.5 per club

Value Now - New target value - Add or reduce wgt

6i D2 - D1.5 - Reduce 0.5 SWP

7i D3.5 - D2 - Reduce 1.5 SWP

8i D2.5 - D2.5 - No Change

9i D2 - D3.0 - Add 1.0 SWP

PW D3.5 - D3.5 - No Change

GW D4 - D4 - No change

If both the #9 and #6 iron feels "just right"m the SW system is better for you, and then they should all be D2 up to the 9, so the question is, what clubs feels right, and what clubs dont? (i understand the #7 dont feel right?)

evog42 · July 27

3 hours ago, Howard_Jones said:

How does your GW, PW and #8 iron feel?
What about the #6 iron?
What about the #9?

If lenght and all other specs is found to be right, and this is how they looks like now, all depending on how the clubs im asking about works for you, there would be 2 different routes to a set that works.

If the GW, PW and #8 iron feels right for you, the #9 feels "light", and the #6 feels a tiny tad heavy, the way to go for you, would be a progressive SW slope with 0.5 per club

Value Now - New target value - Add or reduce wgt

6i D2 - D1.5 - Reduce 0.5 SWP

7i D3.5 - D2 - Reduce 1.5 SWP

8i D2.5 - D2.5 - No Change

9i D2 - D3.0 - Add 1.0 SWP

PW D3.5 - D3.5 - No Change

GW D4 - D4 - No change

If both the #9 and #6 iron feels "just right"m the SW system is better for you, and then they should all be D2 up to the 9, so the question is, what clubs feels right, and what clubs dont? (i understand the #7 dont feel right?)

Edited July 27 by evog42
Forgot to submit reply

evog42 · July 27

Howard, thank you. My 9i feels a little light (although it's actually closer to D2.5), 7i a little heavy; all others feel fine. I could add a gram of tape to the 9i; I'm curious whether the 7i is just a mistake from Mizuno on all 7i, or whether its just mine. Also wondering if OP sent back to Miz to fix.

Smokey227 · July 27

2 hours ago, evog42 said:

Howard, thank you. My 9i feels a little light (although it's actually closer to D2.5), 7i a little heavy; all others feel fine. I could add a gram of tape to the 9i; I'm curious whether the 7i is just a mistake from Mizuno on all 7i, or whether its just mine. Also wondering if OP sent back to Miz to fix.

I am assuming you have checked the lengths? The reason i asked is I have ordered 2 sets from Mizuno and in both sets there were some length outliers in the set that made them swingweight higher. In every instance the shaft wasnt seated properly and the length was off.

925 Forged 7 iron was 263.1 and 925 HMP 7 iron was 263.5 in the sets and both sets had pretty solid although not perfect weight progression but nothing that would cause that kind of swing unless the tip weights was really off.

evog42 · July 27

30 minutes ago, Smokey227 said:

I am assuming you have checked the lengths? The reason i asked is I have ordered 2 sets from Mizuno and in both sets there were some length outliers in the set that made them swingweight higher. In every instance the shaft wasnt seated properly and the length was off.

925 Forged 7 iron was 263.1 and 925 HMP 7 iron was 263.5 in the sets and both sets had pretty solid although not perfect weight progression but nothing that would cause that kind of swing unless the tip weights was really off.

So, I think you've identified the culprit. I had them checked for length initially, but just did a rough measure (I don't own a playing length ruler) and the 7i is definitely closer in length to the 6i than to the 8i. I'd guess it's around 1/8" off, which would explain the swingweight discrepancy. Idk if the grip wasn't pushed down all the way, but I'll see when they're regripped. In any case, I'll be gripping down slightly on the 7i now!

Thank you.

Howard_Jones · July 28

16 hours ago, evog42 said:

So, I think you've identified the culprit. I had them checked for length initially, but just did a rough measure (I don't own a playing length ruler) and the 7i is definitely closer in length to the 6i than to the 8i. I'd guess it's around 1/8" off, which would explain the swingweight discrepancy. Idk if the grip wasn't pushed down all the way, but I'll see when they're regripped. In any case, I'll be gripping down slightly on the 7i now!

Thank you.

1/8" = 0.75 SWP

3/16" = 1.125 SWP

2/8" = 1.5 SWP

This is quite common, especially after a grip chabge*** and thats why i wrote " if play lenght and other specs (like total wgt), is found to be good....then do this....

We need a Golfruler, and should always start with that. If you dont have one, here is a dirt cheap DIY suggestion for how you make one, it takes a few minutes, and cost 1 x letter paper sheet.

***

- if lenght seems off, measure how long the grip is installed, and compare "tip of the grip" to first step. When grips is fully seated, and non of them is "streched", the distance from grip tip to first step shall be the same for all.

If #7 has equal grip lenght, but a longer distant from grip tip to first step, its not the shaft thats cut too long, but the grip thats not fully seated.

When we install grips, its a good idea to measure the grips "insert depth" and set a tape marker around the grip on that spot. Then its easier to avoid variable installed grips. Remember to push the grip butt against the floor when you think its fully seated, to knock it in place in case its a millimeter or more off..

If grips looks good, compare hoseltop to first step to see if thats where the extra lenght comes from (not fully inserted shaft).

If its head wgt alone that moves SW, we will normally be able to identify the issue by comparing total wgt, where the #7 shall be off and higher in wgt than expected due to higher head wgt than it should have.

So..we do have methods to find the issue without pulling everything apart

Edited July 28 by Howard_Jones