Browsing Irons with MPF Data (Older Players CB, High MOI, Low VCOG)

[NRJyzr]

On 11/27/2021 at 1:31 PM, bladehunter said:

100 %. If you have some speed , this is a real thing.  I played i500 for 8/9 months exclusively, built for me with identical shaft I had been using.  Every once in a while I’d hit some god awfully long short iron.  Something like a 170 yard 9 iron.  Or a 200 yard 7 iron.  Just boom.  Touch them all. Gone.  
 

i assure you these weren’t just flush shots.  I played them to a +.05 or so handicap then and had worn the middle of the faces off the short irons.  This was a shot that you caught a groove higher , and would just rocket up and out.  It was so predictable that I’d do it on purpose on some par 3s. To get it to go sky high and land soft.  Hit way  less club , tee it up a slight hair and watch it launch. Hit a normal iron up there on the face and it comes out dead.  
 

In the end just too unpredictable to keep using.  That and I hated the long irons off the deck.  

 

This has been running along in my background processor for a few days...

 

Back when I was playing my ISI set, I had a three week period where I was hitting my irons an extra club or more.  Ridiculous distances for an out of shape 50something.  At first, I wondered if I was seeing fliers, as some of the shots were out of the rough, but it was consistent for those three weeks from every lie, including tee.  My contact pattern was a little higher on the face, but that was pretty normal for me, especially then.  

 

That distance disappeared after about three weeks to a month.

 

I've wondered off and on if I was seeing that spin phenomenon.  As I was thinking back to it, I remembered I switched golfballs around the time it disappeared.  It might have been when I ran out of my stash of Chrome+ and moved to something else that I no longer remember; it's all speculation at that point.  But, it seems logical that my clubs and choice of ball put me in that flier-no-flier extra distance zone, and my ball change may have helped move me out of it.

 

I tried replicating it at 2nd Swing, but couldn't.  Harder to hit higher on the face with mats.  <shrug>  I'm sure they thought I was yet another guy with a delusional distance outlook.  LOL

 

(it was also the session where my Golden Rams shined as a control club)

 

[joostin]

The C Dimension, that @ThinkingPlus and @Cwebb advocate, makes a whole lot of sense for most golfers.  Though I look at MOI, I think it can be a little deceiving looking at it alone for "forgiveness" because of different designs and fact that the hosel affects it greatly.  Mass away from the axis of rotation increases MOI (Maltby looks like they measure MOI vertically at CG, shown below).  Hosels do a good job in bringing a lot of mass away from the clubface, and keeping MOI up.  But that can be at the expense of the hitting area....

 

You don't really see crazy low MOIs on blades because of this.  So they're not necessarily hard to hit or completely unforgiving vs. a CB, but if they have relatively high MOI because of long hosels, and low C Dim, you do stand a higher chance of the dreaded sh@nk!

 

I've tended to not look at C Dim much as I'm kind of used to a compact blade length and miss thin more than far toe or heel, but I'd definitely be open to longer ones or higher C Dims in the future because it's just practical. 

Callaway's old short hosel irons had relatively low MOI compared to GIs today:

 

But look at the high MOI of this old blade:

 

These have similar MOIs but significant C Dim difference because of different mass distribution:

[ThinkingPlus]

6 hours ago, joostin said:

The C Dimension, that @ThinkingPlus and @Cwebb advocate, makes a whole lot of sense for most golfers.  Though I look at MOI, I think it can be a little deceiving looking at it alone for "forgiveness" because of different designs and fact that the hosel affects it greatly.  Mass away from the axis of rotation increases MOI (Maltby looks like they measure MOI vertically at CG, shown below).  Hosels do a good job in bringing a lot of mass away from the clubface, and keeping MOI up.  But that can be at the expense of the hitting area....

 

You don't really see crazy low MOIs on blades because of this.  So they're not necessarily hard to hit or completely unforgiving vs. a CB, but if they have relatively high MOI because of long hosels, and low C Dim, you do stand a higher chance of the dreaded sh@nk!

 

I've tended to not look at C Dim much as I'm kind of used to a compact blade length and miss thin more than far toe or heel, but I'd definitely be open to longer ones or higher C Dims in the future because it's just practical. 

Callaway's old short hosel irons had relatively low MOI compared to GIs today:

 

But look at the high MOI of this old blade:

 

These have similar MOIs but significant C Dim difference because of different mass distribution:

Long hosels and small C dimension correlate well.  High MOI tends to correlate to more toe and top line mass (maximizing perimeter weighting).  This is why the very highest MOI irons tend to have large C dimensions (good), but high VCOGs (generally not good).

Edited December 6, 2021 by ThinkingPlus
Spelling correction...

[NRJyzr]

56 minutes ago, joostin said:

C Dimension, that @ThinkingPlus and @Cwebb advocate, makes a whole lot of sense for most golfers.  Though I look at MOI, I think it can be a little deceiving looking at it alone for "forgiveness"

 

I tend to look at MOI for forgiveness, and C Dimension for aligning with strike tendencies.  It brings up something we don't always see discussed, how MOI and CG location work together. 

 

If you have a forgiving club, but your tendencies have you hitting the ball farther from the CG than a less forgiving club, you could see the two clubs appear opposite to what the MOI indicates in forgiveness terms.

 

It's why the ISI didn't work for me.  My primary miss has always been heelside, the ISI has a higher C-Dim...  yeah, not so wonderful a combo.

 

And blah blah blah 😁

 

[Valtiel]

On 12/5/2021 at 9:26 AM, joostin said:

I've tended to not look at C Dim much as I'm kind of used to a compact blade length and miss thin more than far toe or heel, 

Yeah same here. I occasionally struggle with this because the J40 DPCs are a bit stretchy when it comes to blade length. I feel like I have to hit a few dozen balls before my brain sort of calibrates itself to the longer blade length and I stop noticing it. It's really the only thing that has me considering moving on from them as I can get both a more preferred compact look AND higher MOI in some of these Titleist 718/Mizuno JPX forged offerings. 

@joostin In the various little mockups you have done, particularly the CG location ones, are you able to estimate impacts on MOI as well? I swingweight my DPCs by filling the little toe side pocket cavity with tungsten putty and covering it with lead tape. It is adding weight low and toe side, but I didn't think it would be enough to make a meaningful difference in anything (usually 6-8g). Just curious, thanks!

[Cwebb]

On 12/5/2021 at 9:26 AM, joostin said:

I've tended to not look at C Dim much as I'm kind of used to a compact blade length and miss thin more than far toe or heel, but I'd definitely be open to longer ones or higher C Dims in the future because it's just practical. 

 

A really interesting test club for you would be the Maltby TE or DBM.   They have the really low AVCOG at .675" that is great for a sweeper, along with the longer C-dimension at 1.383" that you're open to trying.  Definitely easier to hit and more forgiving than the various Mizuno MP designs

[Cwebb]

On 12/5/2021 at 9:33 AM, ThinkingPlus said:

Long hosels and small C dimension correlate well.  High MOI tends to correlate to more toe and top line mass (maximizing perimeter weighting).  This is why the very highest MOI irons tend to have large C dimensions (good), but high VCOGs (generally not good).

 

Along with a taller face.  All it can take is a few extra millimeters of face height and we end up with an AVCOG (sweet-spot) that is too high for many players

[ThinkingPlus]

25 minutes ago, Cwebb said:

 

Along with a taller face.  All it can take is a few extra millimeters of face height and we end up with an AVCOG (sweet-spot) that is too high for many players

Yes, but that part of the club is so necessary and useful. 😉

[NRJyzr]

1 hour ago, ThinkingPlus said:

Yes, but that part of the club is so necessary and useful. 😉

 

Especially with Golden Rams in the bag   LOL

 

[Cwebb]

2 hours ago, ThinkingPlus said:

Yes, but that part of the club is so necessary and useful. 😉

 

Oversized!!  They see bigger and think it has to be easier to hit

[ThinkingPlus]

20 minutes ago, Cwebb said:

 

Oversized!!  They see bigger and think it has to be easier to hit

It is easier to hit the ball, but the ball doesn't necessarily end up where you want it.

[scotty_2987]

I just picked these up last week and they are extremely easy to hit and feel amazing. Shot my best round in a couple years and even the 3 iron was fun to hit. 

[ThinkingPlus]

29 minutes ago, scotty_2987 said:

I just picked these up last week and they are extremely easy to hit and feel amazing. Shot my best round in a couple years and even the 3 iron was fun to hit. 

Not surprising.  VCOG is very low so launching those high should be easy.  C dimension is reasonable while MOI is a little low, but not a huge issue if your ball striking is decent.

[joostin]

9 hours ago, Valtiel said:

In the various little mockups you have done, particularly the CG location ones, are you able to estimate impacts on MOI as well? I swingweight my DPCs by filling the little toe side pocket cavity with tungsten putty and covering it with lead tape. It is adding weight low and toe side, but I didn't think it would be enough to make a meaningful difference in anything (usually 6-8g). Just curious, thanks!

Yep, for the one below, adding 4g to the toe, it increased from 11.908 oz-in² without tape to 12.198 with the tape (or 2178 g-cm² to 2231).  That's from the left box of numbers taking MOI around a vertical axis at the CG like MPF does.  Though you're adding more weight I'm guessing it's not too meaningful an MOI increase, but an increase nonetheless!

 

[joostin]

9 hours ago, Cwebb said:

 

A really interesting test club for you would be the Maltby TE or DBM.   They have the really low AVCOG at .675" that is great for a sweeper, along with the longer C-dimension at 1.383" that you're open to trying.  Definitely easier to hit and more forgiving than the various Mizuno MP designs

Yeah that caught my eye, and could be a cheap single club experiment.  It was in the first post's list of clubs that I'd like to try.  I have no real desire to change anytime soon, but it would be high on the list when the time comes.

[joostin]

So just for fun I have an old blade 1 iron Wilson Staff FG-53 Gooseneck that I bring to the range every so often because nothing feels like it even with crap range balls.  I didn't hit a single bad shot with it the other day, sweeping off the mat and even stingers off a high tee... best club of the day lol.  It's a little longer blade, and I'm guessing fairly low VCOG and not too terrible C Dim.  Honestly not that scary to look at.  Gotta go in the bag for one round!

[Cwebb]

1 hour ago, joostin said:

Yeah that caught my eye, and could be a cheap single club experiment.  It was in the first post's list of clubs that I'd like to try.  I have no real desire to change anytime soon, but it would be high on the list when the time comes.

 

There's even the possibility of combo setting them with your Mizuno MP's.  You might try one in a longer iron (4 or 5i) to see if you gain anything in a club # that is a little harder to hit in general  

[Valtiel]

1 hour ago, joostin said:

Yep, for the one below, adding 4g to the toe, it increased from 11.908 oz-in² without tape to 12.198 with the tape (or 2178 g-cm² to 2231).  That's from the left box of numbers taking MOI around a vertical axis at the CG like MPF does.  Though you're adding more weight I'm guessing it's not too meaningful an MOI increase, but an increase nonetheless!

 

 

Thanks very much for that! That is actually maybe a tiny bit more than I was expecting. 

 

1 hour ago, joostin said:

So just for fun I have an old blade 1 iron Wilson Staff FG-53 Gooseneck that I bring to the range every so often because nothing feels like it even with crap range balls.  I didn't hit a single bad shot with it the other day, sweeping off the mat and even stingers off a high tee... best club of the day lol.  It's a little longer blade, and I'm guessing fairly low VCOG and not too terrible C Dim.  Honestly not that scary to look at.  Gotta go in the bag for one round!

Those are pretty sharp looking. Looks like they had their own "cut muscle" sort of design going there. 

[Bob Pegram]

On 11/27/2021 at 6:14 AM, joostin said:

Yes!  Should be another thread but the mg$ CG vs MOI chart shows a grouping of those cult drivers - high MOI with low CG (help gear low spin).  Circled below, from LTD Pro to G400 Max / PXG Gen2, with what I see as the unicorn goal driver.  It's the reason I chose a TS2.

I was trying to find the page you show with the comparison of driver centers of gravity. I can't find it. Can you list it? Thanks.

[joostin]

29 minutes ago, Bob Pegram said:

I was trying to find the page you show with the comparison of driver centers of gravity. I can't find it. Can you list it? Thanks.

Here you go:

 

[Bob Pegram]

12 hours ago, joostin said:

Here you go:

 

Thanks, but I was looking for the original Golfwrx page that measured COG location, etc. for drivers from every year from about 2015 onward if I remember correctly.. You called it the "forum to be unnamed" in your post. I thought I saved the URL, but when I copied it and tried to go there it didn't come up. I made have had the wrong link.

[joostin]

46 minutes ago, Bob Pegram said:

Thanks, but I was looking for the original Golfwrx page that measured COG location, etc. for drivers from every year from about 2015 onward if I remember correctly.. You called it the "forum to be unnamed" in your post. I thought I saved the URL, but when I copied it and tried to go there it didn't come up. I made have had the wrong link.

That "unicorn driver" thread was the only one I posted saying "forum to be unnamed" with those 2015-2019 CGs/MOIs.. had the same diagram from this thread plus more.  Check the link above again?

[Wardonation]

I am in the Cobra MIM Tours. I love them. I am a picker 0 AOA w/ 7 iron and only wish the soles were thinner. I think I like them because of the low CG? At least that was my theory when I purchased them...

[gdb99]

On 11/27/2021 at 5:49 PM, ThinkingPlus said:

I look at VCOG, C dim., bounce, and MOI in that order.  VCOG needs to be between 0.8" and 0.75" (too low makes punching out from under trees a bit too challenging).  I play the majority of my golf off very firm, tight lies and need some vertical forgiveness because normal divots = orthopedic surgery.  The C dimension needs to be greater than about 1.2".  Could I handle less?  Yes, but why would I want to.  Placing the horizontal CG close to the hosel has no advantage and is design stupidity based on tradition.  Bounce needs to be less than 8° throughout the set.  If I played sloppy, lush courses maybe my bounce criteria would change.  Finally, more MOI is better, but it is a nice to have or tiebreaker; not all that important in an iron.

When looking at the Maltby charts with all the data, are you looking at Basic VCOG or Actual VOCG?

[Cwebb]

3 hours ago, gdb99 said:

When looking at the Maltby charts with all the data, are you looking at Basic VCOG or Actual VOCG?

 

Always look at Actual VCOG, because this is the actual height of the COG (sweet-spot).

 

They calculate it by using the basic VCOG and the Rearward COG measurements

[Cwebb]

On 12/18/2021 at 9:58 AM, Wardonation said:

I am in the Cobra MIM Tours. I love them. I am a picker 0 AOA w/ 7 iron and only wish the soles were thinner. I think I like them because of the low CG? At least that was my theory when I purchased them...

 

Yeah, they have a fairly low/mid AVCOG at .777".  As a sweeper/picker that's pretty good.  IF you came from playing something with a higher AVCOG, such as above the center of a ball at (.840), you would likely notice this improvement right away, in terms of easier to hit and higher percentage of solid contact.  You might even test something lower, if you ever have the chance.

 

As a sweeper with this design, the sole width being a little wider shouldn't be a factor at all, since you're not really getting into the turf much.  What really makes a difference, is the AVCOG being low enough so that you can get under the center of the ball from a normal to tight lie. 

 

With something that has a sweet-spot that is too high, that's where the sole width can become a factor for the sweeper, because now you're having to go down more through impact to find solid contact...and the wider sole can make that a little more difficult to do.

 

They have a C-dimension of 1.339", which is very good for the length of that face.  This pretty much guarantees that the COG (sweet-spot) is in the center of the face and not heel side at all.  Makes them easier to hit in general and forgiving on the toe side of center especially.

 

The MOI at about 13.5 is a bonus and slightly enhances the top priorities, which is the height and horizontal location of the COG (sweet-spot) 

Edited December 20, 2021 by Cwebb

[ThinkingPlus]

13 hours ago, gdb99 said:

When looking at the Maltby charts with all the data, are you looking at Basic VCOG or Actual VOCG?

Like @Cwebb said, only look at actual.  Was at an all day party so just now catching up.

[vandyfan]

Are there any other resources (I doubt it) that do AVCOG calcs on irons? I have some Ben Hogan PTxPros that I am curious what the AVCOG is but the Maltby Hogan section does not rate the PTxPros. I doubt that I would be able to calculate this myself?

[joostin]

20 hours ago, vandyfan said:

Are there any other resources (I doubt it) that do AVCOG calcs on irons? I have some Ben Hogan PTxPros that I am curious what the AVCOG is but the Maltby Hogan section does not rate the PTxPros. I doubt that I would be able to calculate this myself?

Maltby's the only one around published unless there are individuals out there measuring for themselves.

 

Its possible to DIY, and their method is spelled out here:  https://ralphmaltby.com/method-of-determining-mpf/

You'd need the head free (preferably 6 iron or around high 20°s to 30° to compare best with MPF data).  Put some masking tape on the face and sole and try to balance on a retractable pen or Sharpie, then measure the marks.

 

Btw even when performing the easiest balance - on the face - doing it multiple times to confirm, you'll get varying marks, and might want to take the average/center of those marks.  Those measuring for the Maltby MPF numbers that we see would also experience variation.  No one would be exactly balancing free on a sharp pinpoint, and they're likely using a hand to keep the head from tipping over especially when balancing on the sole.

 

So all measurements are really close approximations, and can vary a little from person to person and even from a single person.  Also it's likely a single sample measured, and as we know just one club in a set.  It's data worth having and analyzing, but we should just keep in mind there will be measuring and manufacturing tolerances that are unknown.  Measuring variability is most likely bigger than manufacturing variability. 

[ThinkingPlus]

9 minutes ago, joostin said:

Maltby's the only one around published unless there are individuals out there measuring for themselves.

 

Its possible to DIY, and their method is spelled out here:  https://ralphmaltby.com/method-of-determining-mpf/

You'd need the head free (preferably 6 iron or around high 20°s to 30° to compare best with MPF data).  Put some masking tape on the face and sole and try to balance on a retractable pen or Sharpie, then measure the marks.

 

Btw even when performing the easiest balance - on the face - doing it multiple times to confirm, you'll get varying marks, and might want to take the average/center of those marks.  Those measuring for the Maltby MPF numbers that we see would also experience variation.  No one would be exactly balancing free on a sharp pinpoint, and they're likely using a hand to keep the head from tipping over especially when balancing on the sole.

 

So all measurements are really close approximations, and can vary a little from person to person and even from a single person.  Also it's likely a single sample measured, and as we know just one club in a set.  It's data worth having and analyzing, but we should just keep in mind there will be measuring and manufacturing tolerances that are unknown.  Measuring variability is most likely bigger than manufacturing variability. 

It's truly sad the OEMs don't provide this information to the consumer.  The CAD models can calculate the values very precisely.  They don't have to build their marketing campaigns about the numbers.  Just provide them as part of the specs like loft, offset, lie, etc... .