Was a flat-faced Driver ever made?

[Nels55]

9 hours ago, Stuart_G said:

 

There is a subtle difference.   The further back the c.g. the less the gear effect and it's not because the rate of rotation changes.  Again, c.g. location does factor into the amount of gear effect but it does not effect the rate of rotation of the head.

 

 

 

I never said higher MOI meant more gear effect.   I only said: "the MOI becomes a significantly more dominant factor in how much gear effect will be generated. "

 

Basically in the case of comparing gear effect for different drivers that only means,  forget the c.g. location, you only need to pay attention to MOI.

The further back the COG the more the gear effect.  

Read about it here:

http://www.tutelman.com/golf/ballflight/gearEffect.php

 

Forget the COG location?  Let's see the data to support that assertion!

 

[Stuart_G]

38 minutes ago, Nels55 said:

The further back the COG the more the gear effect.  

Read about it here:

http://www.tutelman.com/golf/ballflight/gearEffect.php

 

Forget the COG location?  Let's see the data to support that assertion!

 

 

Yes, that was a typo - it was supposed to be the "further forward" but the rest is still true.

[Nels55]

3 hours ago, Stuart_G said:

 

Yes, that was a typo - it was supposed to be the "further forward" but the rest is still true.

Well, considering that moving the COG by moving adjustable weights or whatever can significantly change a driver head's tendency to hook or slice I would say that the position of the COG plays a very large factor in determining gear effect.

[Stuart_G]

10 hours ago, Nels55 said:

Well, considering that moving the COG by moving adjustable weights or whatever can significantly change a driver head's tendency to hook or slice I would say that the position of the COG plays a very large factor in determining gear effect.

 

That's lateral motion of the c.g.  not forward and backward so that's really still an indication of the driver properties as whole (including MOI) and not the location in isolation of MOI.   It's also arguable how significant the contribution to the side spin really is from movable weights - but that's a topic for another discussion.

 

But you don't have to take my word for it.  You've got access to the equations so can do the math yourself. Just working off memory here so you might want to double check these numbers but for the most common models (there are always exceptions and outliers that can be found).

MOI tends vary from about 4000 to 5600 gm cm^2.

rear-ward c.g tends to vary from 34 cm to 42 cm.

 

Edited January 29, 2021 by Stuart_G

[Nels55]

2 hours ago, Stuart_G said:

 

That's lateral motion of the c.g.  not forward and backward so that's really still an indication of the driver properties as whole (including MOI) and not the location in isolation of MOI.   It's also arguable how significant the contribution to the side spin really is from movable weights - but that's a topic for another discussion.

 

But you don't have to take my word for it.  You've got access to the equations so can do the math yourself. Just working off memory here so you might want to double check these numbers but for the most common models (there are always exceptions and outliers that can be found).

MOI tends vary from about 4000 to 5600 gm cm^2.

rear-ward c.g tends to vary from 34 cm to 42 cm.

 

I think that you mean mm as 34cm = 13.38 inches?

 

I happen to have several SLDR heads so I measured the COG on one vs. the COG on a Mizuno JPX EZ head.

I measured the COG on the Mizuno to be about 41.7 mm back from the face.

I measured the COG on the SLDR to be about 33.7 mm back from the face.

So a difference of 8 mm or .315 inches.  

LOL very close to your memory.  

 

Okay, I believe that understand your point now and unfortunately I missed the fact that you said that the SLDR had more gear effect due to the lower MOI in an earlier post which does make sense.  It seems that the low MOI is the reason why Taylormade did not change the bulge on the SLDR head to accommodate the forward COG which is something that I had wondered about. 

 

I never had much luck with the SLDR heads, I tried putting two ten gram weights in to try to make the head more stable but I could not move them far enough towards the toe and heel without moving the COG too high due to the radius of the sole.  Everyone who I know who tried the SLDR hated it, most were high single digit handicaps or worse.  I think that the SLDR was for elite ball strikers only.

 

As for the OP's question it seems that a flat faced driver would require a very forward COG with a high MOI.  Might be difficult to do as it would be hard to keep the COG low enough without having some sort of a flat bottom. 

 

  

[Stuart_G]

1 hour ago, Nels55 said:

I think that you mean mm as 34cm = 13.38 inches?

 

Yes.

 

 

Quote

I happen to have several SLDR heads so I measured the COG on one vs. the COG on a Mizuno JPX EZ head.

I measured the COG on the Mizuno to be about 41.7 mm back from the face.

I measured the COG on the SLDR to be about 33.7 mm back from the face.

So a difference of 8 mm or .315 inches.  

LOL very close to your memory.  

 

It happens every once in a while 🙂

 

But more detailed measurements are available at the MGS web site - for both c.g. and MOI.

 

Quote

Okay, I believe that understand your point now and unfortunately I missed the fact that you said that the SLDR had more gear effect due to the lower MOI in an earlier post which does make sense.  It seems that the low MOI is the reason why Taylormade did not change the bulge on the SLDR head to accommodate the forward COG which is something that I had wondered about. 

 

I never had much luck with the SLDR heads, I tried putting two ten gram weights in to try to make the head more stable but I could not move them far enough towards the toe and heel without moving the COG too high due to the radius of the sole.  Everyone who I know who tried the SLDR hated it, most were high single digit handicaps or worse.  I think that the SLDR was for elite ball strikers only.

 

Face impact didn't have to be perfect, but it definitely needed to be very consistent in order to get consistent results.   Most am's play drivers too long (at the stock playing lengths) to be very consistent with face impact.

 

Quote

As for the OP's question it seems that a flat faced driver would require a very forward COG with a high MOI.  Might be difficult to do as it would be hard to keep the COG low enough without having some sort of a flat bottom. 

 

  

 

Likely some severe heel and toe weighting - might as well not even be a wood - more like a super sized, low lofted iron.

 

 

Edited January 29, 2021 by Stuart_G