Question for Mr. Kobayashi on his driver designs

[ant]

i realize that there is probably no way the man reads this but hoping that maybe someone from TSG staff by chance can get an answer from him directly.

the question is "why lie angles on his driver head designs are so upright ?". this goes for his last 3 designs known to me such as zero (60), T388 (60) and XV (61).

the reason being cited for this most by club designers is the shaft droop that flattens the angle at impact. the very old standard was ~50 degrees then it went up to ~55 degrees and now modern standard is ~60 degrees. now i do understand that shafts got longer and very stiff steel shafts were replaced by unstable in early days graphite and bigger frying pan heads that had CG moved too deep in the back and all these factors contributed to various degree to increased shaft droop. however these days shafts, especially premium ones got extremely stable even at longer length and judging by the footage i have seen taken with professional slow motion cameras of tour players or long drive hitters who play extra stiff shafts and apply the most humanly possible forces on them the shaft droop isnt that much of an issue as it perhaps used to be a while back. another reason being cited is more upright lie angle helps a slicer with higher rate of closure thru impact but i do not believe it was one of design goals for either zero or T388 because T388 description says, quote "The shorter center of gravity allows the head to rotate naturally for a square impact. This is unlike many drivers on the market today which have long and huge gravity angles which force the head to rotate very quickly causing better players to over rotate the head." end quote. cant dig out zero description but i'm sure its roughly the same. so thats clearly not the reason.

this is a bit long winded but something prompted me to write this open question because i really wanna understand the reasoning behind such design choice. that something was this picture of Mr. Kobayashi checking out new driver mold at address, see below

toe up at address. for comparison note another one behind him positioned flat on the floor. many tour players now go toe up at address and quite a few play open face heads. one of the reasons an open face head would be desirable is because when you go toe up that closes the face and you counter that with slightly open face. not by much with a low lofted head but enough to make a difference on long drive. would that be really necessary with a flatter lie angle ? anyway, i dont think there is much chance of getting an in-depth answer from the man directly but maybe if other folks here have interest in this then maybe there is a bigger chance with TSG staff help to get an answer.

[gocchin]

Hi Anton,

I actually had asked Kobayashi-san this exact question when I talked with him last month. I noticed the same thing that all lie angles were around 60*.

He explained that based on his calculations of the short CG length coupled with shaft droop on the down swing, 60 to 61* was optimal for his designs for squaring the head at impact.

Keep in mind here while we typically see 60-61* lie angles on heads that are for average golfers and slicers, those heads are heavily weight for a draw, have closed faces and huge gravity angles, rotating the head very quickly.

This not the case on Kobayashi-san's designs and the higher lie angle in his opinion works and actually makes hitting the sweet spot which is a tad towards the heel easier.

[ant]

Thanx Tario, appreciate the answer and the fact that you actually did ask him that! The problem is its still not clear to me how is that supposed to work in terms of flat head at impact (no toe up or toe down that is), the part about squaring the club face i understand. there is practically no shaft droop issue here. couple of snapshots to illustrate from that video of Mr K hitting T388 at address and at impact. its not the best camera for that sorta thing but the angle is alright and you can clearly see how much more vertical his hands go at impact compared to address while shaft droop is almost nonexistent. i'm not judging his swing here by any means, just to illustrate the point. so what would happen with somebody who has a flatter entry into impact ? whats gonna happen to the club face orientation ? will it point slightly left in this case because lie angle is too upright for that and there is almost no shaft droop to flatten it ?

[Vegaman]

I would say the majority if not all golfers, including tour players, have higher hands at impact compared to at address. It comes natural the unwinding of the hips and shoulders. Especially with the driver where the centrifugal force is at it's highest, because of the longer shaft.

Edited April 25, 2013 by Vegaman

[gocchin]

No because the lie angle simply means the toe will be up for someone with a flatter swing plane, it will not necessarily point left.

In this world, there are millions of golfers all with different swings.

Of these millions of golfers how may come in with the driver head perfectly parallel to the ground at impact.

Not a large percentage I would think, and in general most probably have more droop and come in quite upright.

Judging Kobayshi-san's swing probably is not the best thing to do. However if you look at the second image and the blurred head which is about to strike the ball, there is in fact some droop and the head looks much more square, not toe up. However his swing is certainly not text book.

The bottom line is, the lie angle is only one single factor. He made the lie angle 61* because he believes it is optimal based on the other design aspects of the head. If it were any flatter its possible with the CG length and placement, the driver could become a fade machine and he would rather have it draw than fade.

[Vegaman]

And there is definitely shaft droop with the modern shafts, actually probably more than ever with trend being lighter and lighter driver shafts, and somewhat softer flexes that has also been trending. I had a Vega driver (probably still have it somewhere..) that had a very upright lie, both by numbers and visually. Took some getting used to.

Edited April 25, 2013 by Vegaman

[ant]

@Vega very few players return their hands at exact same spot or below. one example from modern players would be Sergio but thats not what i'm talking about. you are tall fellow Vega iirc so that means you are most likely to be more upright as those things also depend on height, arm length, posture as well as swing dynamics as you mention but thats not relevant because some people would be flatter than others and the other way around due to all these factors. i just used Mr K snapshots to illustrate. i dont wanna turn this into swing discussion, not interested in that here, there are plenty of that written (and probably still being written as we speak) elsewhere on the net. if your point is that its just a number that works ok on average for majority of golfers then its duly noted.

[gocchin]

@Vega very few players return their hands at exact same spot or below. one example from modern players would be Sergio but thats not what i'm talking about. you are tall fellow Vega iirc so that means you are most likely to be more upright as those things also depend on height, arm length, posture as well as swing dynamics as you mention but thats not relevant because some people would be flatter than others and the other way around due to all these factors. i just used Mr K snapshots to illustrate. i dont wanna turn this into swing discussion, not interested in that here, there are plenty of that written (and probably still being written as we speak) elsewhere on the net. if your point is that its just a number that works ok on average for majority of golfers then its duly noted.

Not just a number that works with the majority of golfers Anton but one that specifically works with his design aspects. He chose 61* as he believes it is the best compliment for the design of his head. Will it fit everyone? Probably not as there is no club that fits everyone in this world. But if he things its the best lie to have, I believe him! (^_^)

[coops1967]

Two good reason why i like my Mizuno 611 and nunchuk shaft.

The head I ordered at 56.5 deg lie angle.

The Nunchuk shaft is extremely tip stiff - forget about toe droop, and is played at 44" or less length generally, reducing toe droop forces even more.

[ant]

Tario, i simply like to understand how that works because no one ever talks about this (apart from marketing material bs that is) and it still doesnt make sense to me. this is no argument of a hack like me with an industry veteran designer, there couldnt be any. i just like to get an in-depth answer from a guy like him, not just a few lines dumb down for marketing material and such.

lie angle does affect face orientation and toe up would also mean face slightly left. take your lob wedge and put it severely toe up at address and see where its face points after that. far less effect for a driver because of its low loft. does it matter for a driver ? if not why there used to be bendable hosels not that long ago and why heads with adjustable hosels are still available on tour today ? does it affect the ball flight or tour players need this solely for address look and feel adjustment ?

shaft droop and CG placement and upright lie still doesnt make sense to me. i know that shaft droop is affected by 2 things. 1 is the steeper a player is thru impact the more shaft droop there will be. and 2 the farther CG of the club head is from the shaft center line the more shaft droop there will be. the former cannot be controlled by club designed because everyone swings different but the later can be controlled with club head design.

it is established thru physics that the club head CG thru release would try to align with the centerline of the shaft in a straight line. the more off the centerline that CG is located the more possible shaft droop there will be. possible because it can be countered with stiffer shafts, specifically tip stiffer shafts but thats the idea. now lets take Mr K latest head design and the picture you posted on another thread

green line added there by me to illustrate centerline of the shaft at much flatter lie angle (its very flat but lets just stick with it as shows the point i'm trying to make). so if the forces acting on the club make CG try to align itself with the centerline of the shaft in a straight line which lie angle would then give you the least shaft droop and thus truest possible face orientation in this picture ? of course since we are looking at this in 2D thats not entirely accurate and we just looking at vertical CG placement. horizontal CG placement would also play a huge role in this but for this design it is said to be moved more forward towards the face. this in contrast to older frying pan designs that had CG more backward and thus more potential for shaft droop because of that. it seems to me that more upright lie angle in this case would actually induce more shaft droop not less and if we take a more realistic flatter shaft centerline because of CG placement there wont be a need to compensate that much for shaft droop with such an upright lie angle.

[ant]

@coops thats one of the things i'm trying to understand with my questions here. some say the effect is negligible for a driver and should not be a concern, others say if you suffering a hook it is something to be concerned with. there is alot of hearsay and marketing bs about this but nobody ever talks about this in-depth to address these issues properly.

[coops1967]

@coops thats one of the things i'm trying to understand with my questions here. some say the effect is negligible for a driver and should not be a concern, others say if you suffering a hook it is something to be concerned with. there is alot of hearsay and marketing bs about this but nobody ever talks about this in-depth to address these issues properly.

Obviously, as you know, having a too upright lie results in the face pointing left. This is precisely why iron lie angles are considered an important nad most basic part of a club fitting... and HAS NOTHING TO DO WITH TURF INTERACTION. The old wive's tale of 'the heel digging in and face shutting' is utter rubbish. Any iron shot, the ball is long gone before the club hits the ground (unless you prefer to hit all your irons shots fat). An upright lie with an iron hit off a tee will produce the same pull/left shot as if you hit it off the ground... or if you hit the ball off a sidehill lie with the bal above your feet.

With a drivers lower loft, the angular error of incorrect lie angles is much less than say a 9 iron.. but of course the driver goes further - and most importantly the upright lie influences ball curvature - those who are hook prone will absolutely detest absurd 60 degree lie angle drivers (why are Pro's, the best golfers, still having drivers custom bent flat with special head moulds to prevent damaging the head?).

Then there's the issue of what having a driver sitting at address with the toe way up, does to your sub conscious. I think we may under estimate our ability... we routinely change clubs from 9 to 8 or choke down and make adjustments without barely thinking about it... now having that toe up i suspect 'tells' you you're going to have to hump that goat pretty hard to get the handle higher and the clubhead where it 'should' be....

Open face drivers are a band-aid for this lie problem, as it offests the leftward face due to upright lie.

Check this thread

http://thesandtrap.c...degrees-of-loft

here's an excerpt...

"

What's 1.4 degrees? If we ignore curve for now, a ball starting 1.4° left of the target (a righty golfer) will land 4.89 yards left on a 200-yard drive, 6.11 yards left on a 250-yard drive, and 7.33 yards left on a 300-yard drive.

But that's just the start line. How much will the spin axis tilt change the flight? Though θE is only 1.4°, we've grabbed the top vector of the D-Plane and rotated it 8° left, so our spin axis is -8° more than it otherwise would have been.

Trackman results say that: a) For every 5 degrees of tilt in spin axis the ball will curve approximately 3.5 yards to the side per every 100 yards of carry. (Source: http://www.trackman....newsletter7.pdf).

So, 8° is 1.6 times 5, and so we can re-run our numbers: 200 yds -> = 1.6 * 3.5 * 2 = 11.2 yards. 250 yds -> 1.6 * 3.5 * 2.5 = 14 yards, and 300 yds = 16.8 yards.

Adding those to the lateral error, we get:

a) a 200 yard drive will finish roughly 16 yards farther left than it would have been otherwise.

b) a 250 yard drive will finish roughly 20 yards farther left.

c) a 300 yard drive will finish roughly 24 yards farther left."

Edited April 25, 2013 by coops1967

[Vegaman]

@Vega very few players return their hands at exact same spot or below. one example from modern players would be Sergio but thats not what i'm talking about. you are tall fellow Vega iirc so that means you are most likely to be more upright as those things also depend on height, arm length, posture as well as swing dynamics as you mention but thats not relevant because some people would be flatter than others and the other way around due to all these factors. i just used Mr K snapshots to illustrate. i dont wanna turn this into swing discussion, not interested in that here, there are plenty of that written (and probably still being written as we speak) elsewhere on the net. if your point is that its just a number that works ok on average for majority of golfers then its duly noted.

Yeah, thats what I meant. I was also thinking about Sergio as I was writing my post, ha ha. Personally I prefer to not have too much of a high toe look at address. It just 'feels' like I might hit it left. The visual aspect is important of course. But in general I think lie is less important an issue with a droger

[Craig]

I wish my brain could comprehend all this.

My technical limit ends at supos shaft flight drawings

[ant]

@coops thanx, this is exactly what i'm talking about here! i can get the numbers for any driver swing with simulation software and they would be pretty spot on both in initial direction and curvature due to spin axis tilt. the problem is i do not know what initial numbers to punch in to simulate how much off target it would go. its the same about that guy post on sandtrap, hes making a guess on specific shaft droop in degrees. without knowing that it cannot be accessed correctly as there sure to be quite a bit of a difference between say something as little as 2 degrees and something like 8 degrees or maybe even more. so if Mr K designs his head (or other designer for that matter as ~60 degrees seems like industry wide standard these days and certainly not something unique to his designs) and then picks a stock shaft for it based on various criteria how much shaft droop is he factoring in ? i'm sure they do some sort of testing and have numbers at least for their stock shafts or at least have some testing data from their shaft manufacturer so they can maybe calculate based on that, right, i mean its not like he goes to the range like in that video, hits it a few times and then goes oh well it looks about right lets go with that.

Check this thread

http://thesandtrap.c...degrees-of-loft

here's an excerpt...

"

What's 1.4 degrees? If we ignore curve for now, a ball starting 1.4° left of the target (a righty golfer) will land 4.89 yards left on a 200-yard drive, 6.11 yards left on a 250-yard drive, and 7.33 yards left on a 300-yard drive.

But that's just the start line. How much will the spin axis tilt change the flight? Though θE is only 1.4°, we've grabbed the top vector of the D-Plane and rotated it 8° left, so our spin axis is -8° more than it otherwise would have been.

Trackman results say that: a) For every 5 degrees of tilt in spin axis the ball will curve approximately 3.5 yards to the side per every 100 yards of carry. (Source: http://www.trackman....newsletter7.pdf).

So, 8° is 1.6 times 5, and so we can re-run our numbers: 200 yds -> = 1.6 * 3.5 * 2 = 11.2 yards. 250 yds -> 1.6 * 3.5 * 2.5 = 14 yards, and 300 yds = 16.8 yards.

Adding those to the lateral error, we get:

a) a 200 yard drive will finish roughly 16 yards farther left than it would have been otherwise.

b) a 250 yard drive will finish roughly 20 yards farther left.

c) a 300 yard drive will finish roughly 24 yards farther left."

[gocchin]

Tario, i simply like to understand how that works because no one ever talks about this (apart from marketing material bs that is) and it still doesnt make sense to me. this is no argument of a hack like me with an industry veteran designer, there couldnt be any. i just like to get an in-depth answer from a guy like him, not just a few lines dumb down for marketing material and such.

lie angle does affect face orientation and toe up would also mean face slightly left. take your lob wedge and put it severely toe up at address and see where its face points after that. far less effect for a driver because of its low loft. does it matter for a driver ? if not why there used to be bendable hosels not that long ago and why heads with adjustable hosels are still available on tour today ? does it affect the ball flight or tour players need this solely for address look and feel adjustment ?

shaft droop and CG placement and upright lie still doesnt make sense to me. i know that shaft droop is affected by 2 things. 1 is the steeper a player is thru impact the more shaft droop there will be. and 2 the farther CG of the club head is from the shaft center line the more shaft droop there will be. the former cannot be controlled by club designed because everyone swings different but the later can be controlled with club head design.

it is established thru physics that the club head CG thru release would try to align with the centerline of the shaft in a straight line. the more off the centerline that CG is located the more possible shaft droop there will be. possible because it can be countered with stiffer shafts, specifically tip stiffer shafts but thats the idea. now lets take Mr K latest head design and the picture you posted on another thread

green line added there by me to illustrate centerline of the shaft at much flatter lie angle (its very flat but lets just stick with it as shows the point i'm trying to make). so if the forces acting on the club make CG try to align itself with the centerline of the shaft in a straight line which lie angle would then give you the least shaft droop and thus truest possible face orientation in this picture ? of course since we are looking at this in 2D thats not entirely accurate and we just looking at vertical CG placement. horizontal CG placement would also play a huge role in this but for this design it is said to be moved more forward towards the face. this in contrast to older frying pan designs that had CG more backward and thus more potential for shaft droop because of that. it seems to me that more upright lie angle in this case would actually induce more shaft droop not less and if we take a more realistic flatter shaft centerline because of CG placement there wont be a need to compensate that much for shaft droop with such an upright lie angle.

Please do not follow the lines in that image. I made that image to simply illustrate where the centerline is and where the CG is. It may not be 100% accurate nor to scale. Simply to illustrate that the CG distance is 32.91mm, thats it.

Coops thanks for the great info. I am always learning myself and anyone who can point out great info and points like that is much appreciated!

Anton Kobayashi-san was simply at the range again testing the driver. He made the calculations long before that test driver was made. The man has been designing golf clubs for 40 years, 20 as the top designer for Endo (meaning he had a part in the designs of a huge number of drivers that were made including all the big brands in the US and Japan.

All these arguments seem very sound technically and do make sense to me. But I find it strange they why not many manufacturers are going with the flatter lies to accommodate then? 56.5* for the Mizuno is ultra rare by JDM standards. Based on the market here where these clubs are designed for, it appears higher lie angles are the norm. Which is why pros must go out of their way to bend lies flat if they want them, as manufacturers still see the higher lie angle as better for mere mortals and amateurs?

You asked me for the reasoning behind the choice. I think in his opinion and considering the design of the XV, the more upright like suits the wider audience and thats that. In the end how the driver performs is what matters. So far the T.388 and its 60* lie angle seems to have done okay. (^_^)

[ant]

Tario, the image isnt actually accurate, you should have drawn it from different perspective to illustrate that point in your original post, more from the top front view (slightly left of the face to provide proper perspective) rather than from face on view then it would make sense to me but in any case all the lines and description there, aside from the shaft centerline in red and imaginary shaft centerline in green, should be disregarded in the context of what i was trying to explain in my post. like yourself i used that image purely to illustrate my point and its by no means precise or realistic. green line i have drawn there if realized that way would be so flat it would make a golfer hit from their knees or something, again, its just an illustration.

i'm not implying that Mr K doesnt perform proper testing or calculations, it was my attempt at humor (failed again) to highlight that there must be some testing data otherwise on which specific design decisions were based. i was hoping Mr K could be asked to spare a few minutes to make an in-depth comments explaining the issues discussed here based on his knowledge in design and test data which i think would be very educational for people genuinely interested in club design.

56 is becoming ultra rare by not only jdm standards but its practically the same story with every manufacturer globally big or small. 58 is considered flat these days and its getting harder and harder to find either flat head by design or a head with adjustable hosel long enough to allow for safe 4-6 degree bending.

Please do not follow the lines in that image. I made that image to simply illustrate where the centerline is and where the CG is. It may not be 100% accurate nor to scale. Simply to illustrate that the CG distance is 32.91mm, thats it.

Anton Kobayashi-san was simply at the range again testing the driver. He made the calculations long before that test driver was made. The man has been designing golf clubs for 40 years, 20 as the top designer for Endo (meaning he had a part in the designs of a huge number of drivers that were made including all the big brands in the US and Japan.

All these arguments seem very sound technically and do make sense to me. But I find it strange they why not many manufacturers are going with the flatter lies to accommodate then? 56.5* for the Mizuno is ultra rare by JDM standards. Based on the market here where these clubs are designed for, it appears higher lie angles are the norm. Which is why pros must go out of their way to bend lies flat if they want them, as manufacturers still see the higher lie angle as better for mere mortals and amateurs?

[Miuramaniac]

All you have to do is look at that pic of K-san at impact to see why the lie angles are 60*. And that's still probably not upright enough for that swing. Most amateurs are close to that steep with their hands if not more. It's a pet peeve of mine also as my hands are much lower at impact (at least I TRY to have them lower). I can manage with a driver usually and adjust but it gets harder with the FW's to get good contact off the ground with upright lie angles.

[gocchin]

Tario, the image isnt actually accurate, you should have drawn it from different perspective to illustrate that point in your original post, more from the top front view (slightly left of the face to provide proper perspective) rather than from face on view then it would make sense to me but in any case all the lines and description there, aside from the shaft centerline in red and imaginary shaft centerline in green, should be disregarded in the context of what i was trying to explain in my post. like yourself i used that image purely to illustrate my point and its by no means precise or realistic. green line i have drawn there if realized that way would be so flat it would make a golfer hit from their knees or something, again, its just an illustration.

i'm not implying that Mr K doesnt perform proper testing or calculations, it was my attempt at humor (failed again) to highlight that there must be some testing data otherwise on which specific design decisions were based. i was hoping Mr K could be asked to spare a few minutes to make an in-depth comments explaining the issues discussed here based on his knowledge in design and test data which i think would be very educational for people genuinely interested in club design.

56 is becoming ultra rare by not only jdm standards but its practically the same story with every manufacturer globally big or small. 58 is considered flat these days and its getting harder and harder to find either flat head by design or a head with adjustable hosel long enough to allow for safe 4-6 degree bending.

Hi Anton it is true that from a top perspective it would give more of a 3D view of the CG length and from that you could actually more clearly see the gravity angle as well which is very small on this head.

You said the image isn't actually accurate but it is as accurate as S-yards own technical image. (^_^)

Kobayashi-san certainly has tons and tons of data. Not only on the clubs from S-Yard that he designed but from every driver, iron and wedge ever made at Endo.

Brian brought up some good points that I was trying to stress as well... the lie angle is probably suited for the amateur and non pro golfer and in the end that's probably the reasoning.

[ant]

or maybe he has learned over the years to swing more and more upright to accommodate upright lie angles ? if you want flat fws get an older rc pro tp. those heads have long hosels, mine is bent 6 flat from whatever the standard on it was (cant remember) and it works great for me. they are not forgiving but on par distance wise with some newer stuff. tried that marketing inflated rbz while back and it didnt do anything for me distance wise compared to my old rc. rc has incorrect lofts for them tho, mine is labeled 15 but is actually 14, maybe its just the one i got tho. i think you can still get them from tsg.

All you have to do is look at that pic of K-san at impact to see why the lie angles are 60*. And that's still probably not upright enough for that swing. Most amateurs are close to that steep with their hands if not more. It's a pet peeve of mine also as my hands are much lower at impact (at least I TRY to have them lower). I can manage with a driver usually and adjust but it gets harder with the FW's to get good contact off the ground with upright lie angles.

[+TourSpecGolfer]

I like this thread. I appreciate you bringing it up ant. coop thanks for your contribution as well.

I dont think it has to do with K-san's swing. These types of lie angles are the new standard and I haven't seen any adverse effects of having a 60* lie on a driver.

A flatter lie does make sense to me for FW's as they make contact with turf. Whats interesting is this is industry wide, not only for drivers made by K-san or Endo but even factories elsewhere.

It seems like one of the less clearly defined questions out there so I think we need to gather opinions from designers. we know many.

This thread has got me curious so I'll ask Mr.K and others for their thoughts on this. If you could put your question into one simple sentence or paragraph what would you ask?

I'll ask 2 mold makers and 3 designers what their thoughts are on this. I think the answer could be one of the theories already in this post.

[born4golf77]

i too think over the years all players, including tour pros, have their hands much higher at impact than they did years ago. not sure which came first though, higher hands or more upright lie angles. either way they are here to stay until some company decides they should promote flatter is the way to more yardage.

high hands usually comes from an effort to hit the ball harder and hence coming back on a higher plane. with the driver it is easier to get by with b/c the ball is teed up off the ground.

[idrive]

I'd kill for flatter lies, ESPECIALLY FW's. If you look at the bottom of my FW the heel (bottom of club) is practically worn out, the toe looks

like the club has never been hit. Mis hits towards the toe make the result even worse because you don't contact the ball with the entire face.

When I buy a FW (rarely) I buy based on the lie angle being flatter than norm. This leaves very few options.

[bogeydog]

I'd kill for flatter lies, ESPECIALLY FW's. If you look at the bottom of my FW the heel (bottom of club) is practically worn out, the toe looks

like the club has never been hit. Mis hits towards the toe make the result even worse because you don't contact the ball with the entire face.

When I buy a FW (rarely) I buy based on the lie angle being flatter than norm. This leaves very few options.

+1000

[+TourSpecGolfer]

J & B, what about with drivers do you notice any difference in a flatter lie vs more upright?