Unicorn Driver (By Design Based on CG, MOI) 🦄

[joostin]

I posted this in the iron MPF thread, but it's worth its own.  The driver chart below is from the "forum to be unnamed" CG report, which unfortunately hasn't had an update since 2019.

 

The group I circled contain some stars from 2015-2019 that have reached legendary heights - Cobra LTD, TM M2 2016, Ping G400 Max.  In fact the lowest dot circled is LTD Pro and the furthest right dots are G400 Max and PXG XF Gen2.  Lowest CG (vs neutral axis to gear low spin) to highest MOI.  The combination of those two things surely explain to a large degree why those legends exist, and remains high on the design criteria of most drivers today - for forgiveness with lowish spin.

 

I feel the unicorn driver (circled "Goal") would max out MOI yet keep CG very low.  Which is why many heads nowadays have weights that are low and rearward, and protrusions like in SIM, Ping, Cobra... that keep the rear low without sloping up. 

 

 

Reduce weight where it's not needed, and localize it where it creates low CG and high MOI.  The more it can be done the closer it gets to the "goal".  Lightweight crowns; composite materials; super thin titanium; use of aluminum; rear ends that are long and give the triangular look (at the expense of getting away from the classic pear shape).  As much as people scoff at some things (aluminum in my $600 driver?!) or say it's just marketing, it's all helping or attempting to achieve these attributes. 

 

Closer look at some in that range, though again just some 2015-2019 drivers:

 

(Tommy Armour Atomic?!)

 

It's tough design-wise because you can only do so much with a driver shape vs neutral axis to move weight low and rearward in a shape that's "acceptable" at 460cc:

Theoretically you could remove the crown 😆 but practically it probably won't happen!  The pic above helps explain a Launcher-like step down crown and all the efforts with materials and weight distribution these days to move CG low.

*Edit: Also a good pic showing why SLDR's low forward CG was the thing (low spin but lower MOI, loft up for high launch low spin bombs) before companies pushed it further rearward. 

 

Strike is king, and can render these attributes moot, but the engineering is sound in pretty much all the "tech" advances IMO even if they move weight in tiny increments.  COR retention away from center - sweet spot area as I like to say - is the other place we see tech advances like VFT, speed slots, Jailbreak, cup faces to move welds away, etc.  All just getting closer to the unicorn driver design-wise, though some have already found their unicorn that fits their game.  What's your unicorn driver, or what would you like to see?  For me maybe a TSi3 looking head with more weight ports that magically has maxed out MOI and sounds a little softer without hotmelt👌

Edited December 10, 2021 by joostin

[NRJyzr]

Based on the spin results of the clubhead, I would love to see where the Sim's CG is in relation to other clubs.  

 

I think that unicorn area might be very difficult to find, clubhead shapes being what they are...

 

[lefthack]

These topics interest me as a QA Engineer because the one factor that throws all this off is my less than consistent driver swing. Which by chance is unlike many other golfers driver swing. You have speed, angle of attack, swing path, club face orientation, shaft lean angle, blah, blah, blah. I'm lucky if I can get 2 swings to be similar. 🤣

 

So you can design a driver head that is perfect FOR YOU. Or you can design a driver that's perfect for your swing robot. But it seems no two driver swings are the same. So the engineering principles applied are limited to the swing behind the design. That design MIGHT work well for you, but it could be a disaster. But for "Steve" it's amazing.

[prod1]

Great post - fantastic info. Where are the charts from?

[Lemonde]

17 minutes ago, prod1 said:

Great post - fantastic info. Where are the charts from?

The “ unnamed” forum.  Ask yourself what was James Bond’s occupation. 

[joostin]

51 minutes ago, lefthack said:

These topics interest me as a QA Engineer because the one factor that throws all this off is my less than consistent driver swing. Which by chance is unlike many other golfers driver swing. You have speed, angle of attack, swing path, club face orientation, shaft lean angle, blah, blah, blah. I'm lucky if I can get 2 swings to be similar. 🤣

 

So you can design a driver head that is perfect FOR YOU. Or you can design a driver that's perfect for your swing robot. But it seems no two driver swings are the same. So the engineering principles applied are limited to the swing behind the design. That design MIGHT work well for you, but it could be a disaster. But for "Steve" it's amazing.

For sure.  Ooh you got me thinking now..  As an engineer who works closely with the Quality team, I know they say "let the data tell us what the process is capable of".  Well my golf process is for sure one with too much variation!  The equipment itself may work fine and be in spec, but "fix the process".  If you plotted swing variables and shot data I'm guessing they're not up to six sigma standards!  Varying already capable equipment probably won't help but that's where feel comes to play.

 

From the design perspective I do think it's necessary to push the boundaries of what can be done with equipment - even if that means small unnoticeable changes, hype, scoffing, and all.  That's really separate or secondary to what a person is capable of, getting a good feel of the club, and performing with it.  Which can be certainly be done without the latest tech.

[jvincent]

1 hour ago, lefthack said:

These topics interest me as a QA Engineer because the one factor that throws all this off is my less than consistent driver swing. Which by chance is unlike many other golfers driver swing. You have speed, angle of attack, swing path, club face orientation, shaft lean angle, blah, blah, blah. I'm lucky if I can get 2 swings to be similar. 🤣

 

So you can design a driver head that is perfect FOR YOU. Or you can design a driver that's perfect for your swing robot. But it seems no two driver swings are the same. So the engineering principles applied are limited to the swing behind the design. That design MIGHT work well for you, but it could be a disaster. But for "Steve" it's amazing.

 

Good post. I was about to say basically the same thing.

 

In my case, I cannot swing with a large upward AoA with any consistency. Sure, I'll hit the occasional bomb, but more often than not it's way offline. I'm much more consistent delivery the driver at level or very small upward AoA. So the CoG that works well for me won't work as well for somebody who hits up a lot.

[Valtiel]

I remember drawing up the same sort of thing when I first discovered the MG$ CG report stuff. I think I harped about it during the pre-release lead up to the M5/M6 drivers and its something I reference when people beat the "drivers are maxed out, nowhere else to go!" drum. I think I also said back then that face tech would need to make another leap forward to get there as traditional faces, no matter how thin/light, still eat up a lot of weight themselves and with their surrounding supports/welds. Weight that is also all the way forward obviously. I hope this is what Taylormade are exploring with this next lineup.
 

2 hours ago, NRJyzr said:

Based on the spin results of the clubhead, I would love to see where the Sim's CG is in relation to other clubs.  

 

I think that unicorn area might be very difficult to find, clubhead shapes being what they are...

 

I was able to extrapolate the SIM's approximate position based on an MOI chart someone posted from GolfTec. It had other driver heads listed that I could use as reference points and it basically came out to being in a very similar place as the TS3, albeit a tiny bit higher and more forward. It sits really close to something like the Mizuno ST190 and the Cobra F9 with the heavier weight forward. 

And you're right, the "traditional" driver head shape makes this hypothetical unicorn zone extremely difficult. 

Edited November 28, 2021 by Valtiel

[lefthack]

3 hours ago, jvincent said:

 

Good post. I was about to say basically the same thing.

 

In my case, I cannot swing with a large upward AoA with any consistency. Sure, I'll hit the occasional bomb, but more often than not it's way offline. I'm much more consistent delivery the driver at level or very small upward AoA. So the CoG that works well for me won't work as well for somebody who hits up a lot.

 

I have a near flat angle of attack. I tee it a little lower but I have gotten a much more playable drive now. I'm not getting much draw bias from my D type M6, but I'm not slicing into the woods. 🤣

 

My driver lesson helped a lot. I might finally do a driver fitting next year if my consistency keeps improving.

[Nessism]

To me, I target the rearmost CG, and the lower the better.  Realize that while those charts make it seem like there is a large difference in CG height, 3mm is only 1/8" which isn't anything in the real world of ball striking.

[03trdblack]

The upcoming Cobra LTDx driver will have a CG back on the neutral axis and have very high MOI, similar to the original LTD but higher overall MOI. It's already on my must try list for 2022.

[Valtiel]

1 hour ago, 03trdblack said:

The upcoming Cobra LTDx driver will have a CG back on the neutral axis and have very high MOI, similar to the original LTD but higher overall MOI. It's already on my must try list for 2022.

[joostin]

On 11/28/2021 at 10:46 AM, Valtiel said:

I think I also said back then that face tech would need to make another leap forward to get there as traditional faces, no matter how thin/light, still eat up a lot of weight themselves and with their surrounding supports/welds. Weight that is also all the way forward obviously. I hope this is what Taylormade are exploring with this next lineup.

With you on this.  I know there's a long thread in the Tour and pre-release equipment forum on the TM 2022 drivers.  It would make sense if the TM Stealth is the next-gen of exploring lighter faces with composite materials.  Composite faces can only get better than some drivers that had them in the past, and would open different construction avenues.  That'll certainly help the ability to distribute weight closer to unicorn territory. 

 

Try to move heavier weights low-rear by having more light materials up front and high:

[sfdoddsy]

The problem I have with the CG/MOi charts from that site (interesting as I find them and as much as I wish they'd update) is that the theory has little relation to practice.

 

The Cobra LTD, for example, was lauded for its CG position. Yet even Cobra figured it didn't matter and went elsewhere.

 

Taylormade alternate between weight forward and weight back and provide convincing reasons each time.

 

Callaway, as another example, decided that MOI had no relationship to forgiveness. Hence the Mavrik had low MOI, but high consistency.

 

I don't want to pick on the Site, but the 'scientific' annual real world tests they do also have no correlation to practice.

 

One year one club wins, the next the same club loses.

 

The reality is that group tests tell you nothing. We all swing differently and react differently to a club.

 

 

[scooterhd2]

The unicorn driver you are describing (highest MOI, lowest COG) is not going to be maximized for distance, but rather be easy to launch, have more consistent spin, more neutral ball flight. If that is your main goal, just get a 12 or 14 degree driver. 

[03trdblack]

1 hour ago, scooterhd2 said:

The unicorn driver you are describing (highest MOI, lowest COG) is not going to be maximized for distance, but rather be easy to launch, have more consistent spin, more neutral ball flight. If that is your main goal, just get a 12 or 14 degree driver. 

 

I'm not sure I could agree with this statement at all.  Why would I want to take a 12-14 degree driver that has a consistent spin of 3800 RPM and costs me 25 yards when I could have a driver that offers me consistent spin at 2100 RPM, has a low and deep CG and a high MOI?  From a design point of view, It's actually easier to get the center of gravity on or below the neutral axis as you lower the loft.  If you have a center of gravity that is further back, you can play a lower loft that still launches high and you'd get extra ball speed from a flatter face making impact on the ball.  The further back and lower CG also reduce the twist on an off center hit and give you better dispersion.  

 

Bottom line is there are way more considerations that can give you a driver that's maximized for distance AND still optimize you for launch angle, spin, etc.  

[Ri_Redneck]

We all have to remember that even unicorn clubs are still golfer specific to a point. IMHO, MOI is about the only universal spec that is similar for everyone. Everything else varies depending on the golfer, especially loft.

 

I play the LTD Pro, Speedzone, ST180 and ST190. All perform very well for me. I have also hit the Ping G offerings and they also perform well for me (just fugly to my eye). I like the low and deep COG because I find it penetrates the wind better and I play regardless of weather most of the time.

 

BT

[Valtiel]

5 hours ago, scooterhd2 said:

The unicorn driver you are describing (highest MOI, lowest COG) is not going to be maximized for distance, but rather be easy to launch, have more consistent spin, more neutral ball flight. If that is your main goal, just get a 12 or 14 degree driver. 

 

4 hours ago, 03trdblack said:

 

I'm not sure I could agree with this statement at all.  Why would I want to take a 12-14 degree driver that has a consistent spin of 3800 RPM and costs me 25 yards when I could have a driver that offers me consistent spin at 2100 RPM, has a low and deep CG and a high MOI?  From a design point of view, It's actually easier to get the center of gravity on or below the neutral axis as you lower the loft.  If you have a center of gravity that is further back, you can play a lower loft that still launches high and you'd get extra ball speed from a flatter face making impact on the ball.  The further back and lower CG also reduce the twist on an off center hit and give you better dispersion.  

 

Bottom line is there are way more considerations that can give you a driver that's maximized for distance AND still optimize you for launch angle, spin, etc.  

Agreed. There are many differences between the hypothetical unicorn driver here and a 12-14* driver. The first is spin as mentioned, you would need to ALWAYS hit high on the face while also presenting less dynamic loft (forward shaft lean) to launch the high lofted driver in a decent window if you have any amount of speed. Second is efficiency since additional loft will start to impact smash factor. Third is ironically consistency since there is no guarantee that a higher lofted driver will be more consistent. Without the benefits of high MOI, the spin window for the high lofted driver would still be volatile with lower strikes spinning up too much and mishits losing distance more distance. 

The benefits of the unicorn highest MOI/lowest CG driver are going to be related to efficiency and ease of achieving more ideal launch conditions. The higher the MOI the tighter your spin window will be on average, meaning you can exploit going down in loft to both lower spin and increase efficiency without as many of the drawbacks (difficulty launching, spin too low etc). These are all little incremental moves to steal some yards which would be left on the table with a high lofted driver. 

Edited December 8, 2021 by Valtiel

[joostin]

On 12/8/2021 at 12:17 PM, Ri_Redneck said:

We all have to remember that even unicorn clubs are still golfer specific to a point.

 

Sure.  Just to clarify, by "unicorn" I mean by design (changed title).  Yes that unicorn design might not get along in the hands of some people, but some it will.  Some get along better with older drivers than newer ones, and are still swinging Aeroburner, Titleist 905, G20.  Some prefer smaller heads or not so high MOI.

 

The direction design wise is clear though and trending to the max MOI while keeping low CG.  Everyone pretty much has a lightweight crown and weighting at the back.  "Lower" MOIs are not really low anymore.

 

I made a diagram from the other forum's CG / neutral axis pic.  Hopefully it helps explain things to some out there:

 

Strike is key, and variations in strike are much greater than little CG differences in different clubs.  But every millimeter and every gram redistributed counts in design.  They can up over time to significant changes.

 

Again, not saying everyone want or needs these unicorn features.  Some can use more spin, more loft.  Companies have to cater to all abilities and swing speeds.  But the design trend is clear.  Here are some newer heads vs a little older heads:

[NRJyzr]

Love the toe views, showing the then-to-now evolution of head shapes...

 

[joostin]

A few more comments:

 

Titleist and Ping crowns have more slope down towards the back - helping to lower CG - vs the other big names possibly because they don't have composite crowns.  TM, Callaway, Cobra might have that in reserve for future designs. 

 

Adding weight forward does actually raise MOI, just not as much as you can raise it by adding the same weight farther from the CG, ie. the very back of the head.  Weight just has to be far from CG - toe side and heel side weighting also raise MOI - like perimeter weighting.

 

Max allowed MOI, vertically through CG, is 5,900 g-cm² +/-100, but since devices that measure have uncertainty percentages, manufacturers have to be on the safe side.

https://raptor-scientific.com/news/resources/usga-ruling-on-moi-of-golf-clubheads/

 

MOI units are g-cm² (or kg-cm² or oz-in²).  Anyone saying g/cm² is wrong... see it all the time.  Multiplying not dividing.

 

 

Nope USGA, the game is still really hard!

[NRJyzr]

17 minutes ago, joostin said:

 

 

 

Nope USGA, the game is still really hard!

 

I am among the camp that believes the USGA's comments on MOI have come largely true, at the professional level.  Tee game skill has been rendered considerably less important than it was even 20 years ago, much less the persimmon era.

 

[Howard_Jones]

My personal unicorn is still Tom Wishon 919 THi
MOI hoovers at about 5000, RCOG is about 33 mm (memory) VCOG is "just right" (cant recall measurement), , and the patentet face roll with 2 different lofts (GRT) on the face cant be done much better. No matter head i try, they cant make it better than this.

https://wishongolf.com/designs/designs-drivers/919thi/
 

[Ri_Redneck]

6 hours ago, joostin said:

 

Sure.  Just to clarify, by "unicorn" I mean by design (changed title).  Yes that unicorn design might not get along in the hands of some people, but some it will.  Some get along better with older drivers than newer ones, and are still swinging Aeroburner, Titleist 905, G20.  Some prefer smaller heads or not so high MOI.

 

The direction design wise is clear though and trending to the max MOI while keeping low CG.  Everyone pretty much has a lightweight crown and weighting at the back.  "Lower" MOIs are not really low anymore.

 

I made a diagram from the other forum's CG / neutral axis pic.  Hopefully it helps explain things to some out there:

 

Strike is key, and variations in strike are much greater than little CG differences in different clubs.  But every millimeter and every gram redistributed counts in design.  They can up over time to significant changes.

 

Again, not saying everyone want or needs these unicorn features.  Some can use more spin, more loft.  Companies have to cater to all abilities and swing speeds.  But the design trend is clear.  Here are some newer heads vs a little older heads:

I absolutely agree with your point. I was just adding a bit of explanation for those who sometimes buy what others rave about and then find it's not for them. Gotta know your game to avoid that.

 

BT

[Cwebb]

5 hours ago, NRJyzr said:

 

I am among the camp that believes the USGA's comments on MOI have come largely true, at the professional level.  Tee game skill has been rendered considerably less important than it was even 20 years ago, much less the persimmon era.

 

 

I kinda wish they had capped driver size at about 350cc

[joostin]

Some drivers have gotten pretty close to max allowed MOI already.  But just looking at shapes that would allow ease of low CG and max MOI, here's what that might be design wise.  It needs mass distribution low, and distributed far from the CG in XYZ axes.  From a top view, it may mean revisting square shapes again 😳... at least it's accepted with putters!  Maybe we'd see TM with double "inertia generators" that's covered by a normal fat pear top.  From a face view it may mean an upside down shape, like old Adams woods.  Or a normal face that's more conducive to strike patterns that morphs to an upside down shape in the rear.  Mass distribution vs CG:

 

Shape design analysis of 9 drivers:  TM Stealth, Ping G425 Max, Callaway Rogue ST Max, Titleist TSi1, Cobra LTDx, PXG XF Gen4, Srixon ZX5, Mizuno ST-Z 220, TEE C722.

 

Rear weighting: 

Unicorn design would have rear weights hugging the rear skirt.

Top picks:  Ping, Callaway, TM for side mounted weights 

 

Face view:

Unicorn design would have mass low with a light weight hosel.

Top picks, hosel:  Not sure on adapter weights, but Ping probably wins here.  Callaway is stuck with a large adapter.

Top picks, shape:  Maybe Callaway, Titleist, Cobra, PXG, Srixon 

 

Top view:

Unicorn design depends on weight distribution, but it would allow mass to be farthest away from the CG

Top picks:  Maybe Titleist, Callaway, Ping

 

Side toe view:

Unicorn design has low rear skirt and weight with crown sloping down.

Top picks:  Everyone, though TM can slope down their crown more.

.........

With the exception of their adapter, I like the direction of Callaway with Rogue ST over the standard Mavrik and Epic Speed where they favored aerodynamics over MOI, though they are great drivers nonetheless.  Ping of course has been a leader in forgiveness forever.  Their traditional high toe would help MOI, but not so much for lowering CG.  TM's light-weighting features probably allow for the most pear shape of all, but they can certainly morph the shape to lower CG and increase MOI even more in the future.  Everyone's designs here have unicorn traits, but I think there's plenty of room for playing with mass distribution and possibly morphing shapes a bit away from the norm to get even closer to unicorn.

[mitchdoc]

Well the Cobra LTDx might be unicorn as it is 1st driver to hit MOI of 5000 while having CG at the neutral axis.

 

So far reviews have been great in terms of distance and forgiveness.

[joostin]

13 hours ago, mitchdoc said:

Well the Cobra LTDx might be unicorn as it is 1st driver to hit MOI of 5000 while having CG at the neutral axis.

 

So far reviews have been great in terms of distance and forgiveness.

Getting closer for sure.  I saw LTDx and Rogue ST Max LS were called unicorns by their companies.  I do think we'll get to drivers truly challenging the 5900-6000 MOI max while getting CG to or below neutral axis - with materials and maybe design changes per my previous post.  Btw the TS2 measured MOI just over 5000 and 1.7mm CG above neutral axis - not far off for a 2018 offering that can be picked up for cheap, which is actually why I got one, because of that chart!

 

But yeah, if designs can get CGs to neutral axis, why not?  Especially for high speed players.  You don't have to hit as far above center to get potentially favorable spin conditions from gear effect, nor as penalizing high spin from gear effect on lower strikes.

 

Expansion of sweet spots and high COR/CT areas on faces I think are just as important for Unicorn designs, but not as well known because no one has comparative data.  Newer variable face thicknesses like Cobra's HOT and Callaway's AI... jailbreak, flexing slots like TM and Mizuno... They've all been laughed at as gimmicks on WRX, but I bet if we see the FEA simulation studies from their engineers we'd see actual sweet spot improvements.  Their continued use may be testament.  It's clear when some design features stick around.

Edited March 18, 2022 by joostin

[mitchdoc]

Actually cobra is at 5200 MOI

and at CGNA.

I am most impressed with it.

It seems to maintain consistent spin even on heel and toe strikes and low or high on face.

 

[Poolparty]

Any updated numbers here?