Driver Clubhead Size and Performance – Who Wins?

Posted by on Apr 26, 2012 in Clubhead Design, Driver Fitting | 17 comments

I’m well aware there are a number of golfers who can’t stand looking down at drivers which to them, look so large in size they seem like a “grapefruit on the end of a stick.”  Golf equipment information forums will occasionally have threads in which golfer’s plea for the companies to develop and introduce sub 400cc drivers. Within such comments invariably is the question, “can a smaller size driver perform as well as a larger one, and if so, why haven’t the golf companies offered at least an alternative smaller size driver?”

In a nutshell, if they can be sure it will sell enough to far exceed the cost of development and marketing, you can be absolutely sure the golf companies will make it. They’re all in the business of making money. That’s why if you don’t see any smaller size drivers being offered, the companies are sure the demand is just not going to be significant enough to merit the introduction of a smaller size driver. Period.

Way too many golfers still believe that “bigger is better” when it comes to driver head performance to allow companies to spend the money to develop a smaller size model.

From a pure performance standpoint, the larger the size of a clubhead, the higher its Moment of Inertia could be. In turn that means the larger the head, the better it’s off center hit performance could be. Likewise, the larger the size of the head, the larger the face area could be. Larger size face does not mean a higher COR for more distance because we all know it is eminently possible to reach the USGA’s limit on spring face capability on a face that would be commensurate with a sub 400cc size driver head. But a larger size face can make it easier to design a variable thickness face that could offer a very high level of off center hit performance.

Bottom line though is that it very definitely is possible to make a driver head with a volume of 380cc to 400cc that would perform every bit as well for distance and off center hit performance as any of the 460cc heads currently on the market. Yes, the 460cc head’s MOI would likely be higher, but not by so much that it could bring about a noticeable improvement in off center hit performance. MOI modeling studies for TWGT have shown that a difference of 1400 g/cm2 in the MOI of a driver head, basically the difference between a 360cc and 460cc volume head, offers only a difference of ¼ of 1 degree in resistance to off center hit head twisting. And that’s for a golfer with a 109mph clubhead speed. For golfers with a 100mph and lower swing, the additional off center hit improvement from a 1400 g/cm2 difference in MOI is even less.

Hence if all the golf companies could be convinced enough golfers would buy the smaller size driver to make it worth the expense to develop and introduce it, golfers would not skip a beat in terms of the performance they could achieve with a smaller size head. It’s all a matter of supply and demand – and right now there is just not enough demand to generate a supply.

17 Comments

  1. I wonder how the big companies determine what people want. Polling?

    I know I sure wouldn’t mind having smaller driver heads again. :-p

    • Jaacob
      Most of the big OEMS will have consumer golfer focus groups that they convene from time to time to obtain feedback on various things they are considering to offer in their product line. I’ve been told that some of this focus group polling even includes showing these groups different colors they might be considering to use on models to get input even for the cosmetics side of a product in development. Focus groups are usually done by the OEM’s marketing agencies and not by the OEMs themselves so the agencies can bring their professional independent approach to the process. Some OEMS will also have their sales reps poll their retail customers to get some input on what the retailers are being asked by consumers to stock to sell. In short, because it can cost a ton for a big OEM to bring a new product to market, they do not go into this blind. It’s way too expensive if a product launch fails so they definitely do try to get a lot of input before they launch something.

      Here and there we at TWGT do hear a request for a smaller size driver head, but in no way is it enough to seriously consider developing one, even for a small company like us. In the world of uneducated golfers, the very easiest marketing theme to promote is “BIGGER IS BETTER.” Everyone can believe that because it seems so logical to people who know nothing about the technical points of golf club performance. So the OEMs do not want to try to go against such beliefs. Only if they start to hear a TON of requests for a smaller head will you see that happen – and it would have to be a LOT of requests.

      TOM

  2. I don’t automatically find 460cc clubheads to look too big. It kind of depends on their shape and graphics. Some TM Burner heads from 3-5 yrs ago with the pointy back ends didn’t appeal to me. My gamer is a Wishon 919 8* model but I have a Golfsmith Hi Cor Plus 7.5* from 10 plus years ago that I won’t give up, which is 400cc. Both are traditional shapes. I’ve built several Golfsmith, Snake Eyes or Maltby heads over the years which varied in size but none them hit it better than the Hi Cor until the 919. Another factor to consider is the rules allow drivers to be up to 460cc. The world being what it is, things are alway gonna be right up to the limit if technically possible.

    • DAN

      You’re absolutely right that 460cc of volume can be packaged in any number of combinations of length x width x height. So there are 460 heads that look balanced and not so large behind the ball and then there are other 460 heads that just look gaunt, ungainly and too big when you set them down in the playing position. Happy to hear that the 919 is winning a spot in your starting line up. In all honesty I do not think I can ever hope to design a better driver that can offer the overall performance balance for on center + off center performance all in a pretty decent shape that the current 919 has.

      TOM

  3. Hi Tom,

    I have a related question in relation to iron head design. Is a blade more accurate than a cavity or GI iron on strikes right out of the center? have you done any research into this?

    I understand the technology that makes a GI iron more forgiving on off center hits, but does this same technology detract from the accuracy of center strikes? Will a blade have tighter dispersion right out of the middle than the same strike right out of the middle of a players cavity or GI iron? If so, why?

    I always assumed that a solid strike was a solid strike. Just like a strike out of the middle of a 460cc driver will not travel any further than the same strike out of the middle of a 380cc head, why would a cavity backed iron be less accurate right out of the middle.

    And at what level of ball striking ability would you believe it makes sense to play a blade (all other aspects of the game being equal)?

    Thanks

    • AG:

      Good questions and fun to answer. Thanks for asking!

      No, in my opinion from 26 yrs of club design and testing, a blade is not more accurate for on center hits than any other iron head design. You can make some GI designs with a thin, high COR face so they generate a higher smash factor (ball speed divided by clubhead speed) than a blade for sure. But accuracy wise for on center hits, if everything is equal for COR, loft, lie, CG and all assembly specs of a blade vs cavity back, they will be the same for on center hits.

      If the CG were different enough on the two heads, this is where the one with the lower CG could generate a higher launch with more spin, and for some golfers that might mean more fade or draw for an on center hit than a higher CG head. But here again, this is minimal, and in reality, between most muscleback blades and most deep cavity backs, the blade has the lower CG. Yes it does.

      At what level of ball striking ability does it make sense to play a blade? ONLY when you are at the point that you hit 100% of your shots On Center. Seriously. The off center hit advantages of a good cavity back are so superior to that of a blade that I cannot see why any golfer would want to pass up getting the most performance when they do make that swing mistake and hit the ball off center. Even if you only do that a couple of times per round. What if that one time you catch the blade off the toe is a shot to a green with a water hazard hugging tight against the entire front of the green? With blade you just made bogey or double. With good MOI cavity back, you got away with that off center hit and made par.

      I do realize that the LOOK of an iron is of supreme importance to a good player. I get that. So yes, I understand that to get the right LOOK, a good player sometimes gives up some off center hit forgiveness. But there are enough traditional looking cavity back forgings out there today that I do think most players can find one that has the right LOOK – and so then you can get better off center hit performance than with a blade. Me. I think even the tour players who play blades are giving up a half shot to shot advantage per round at the least to those playing cavity backs.

      TOM

    • Thanks Tom.

      Your response is as I thought but I appreciate the way you can convey this knowledge in simple terms.

      But did I read correctly that blades generally have a lower COG than a full cavity?

    • AG

      Yes, every muscleback blade I have ever designed or analyzed, regardless of who made it, did have a lower CG than any cavity back that I have designed or analyzed. It is logical when you think about it. It is because in a blade, because there is no cavity on the back, for the heads to all not be heavier than their assigned headweights, the blade HEIGHT has to be shorter. But on a cavity back where you have removed all this weight from the back, for it to be made to the proper headweight, the cavity back has to be a taller head height. In the world of CG location for irons and wedges, head height is by far, BY FAR the most influential factor in determining the vertical location of the CG. Hence because you almost never see a blade with a taller head height than a cavity back, blades have a lower CG.

      TOM

  4. Tom as somebody who is an expert on club design, what do you think of these companies that advertise that their driver heads are specifically designed for long distance competitors? I notice some of the faces of their clubs don’t have score lines. Will these clubs really hit the ball any farther if the average golfer uses them?

    Thanks.

    • GARY:

      The main difference between the driver heads made for the long drive guys and “normal” driver heads is a slightly increased face thickness, though not too much thicker because they can’t give these guys heads that have a much lower COR. The 130mph to 150mph clubhead speeds of these guys is a huge increase in stress on the face compared to what “normal” heads undergo with regular golfers.

      The COR of the face controls the smash factor of the shot for ALL players, regardless of their swing speed. Smash factor is ball speed divided by clubhead speed. With the maximum COR of 0.830, the highest the smash factor can be is 1.495. If you make the face thicker so it survives a 150mph clubhead speed, it is almost impossible to have the COR be higher than 0.810 to 0.820. From that, the smash factor will be lower and the distance will be less as well.

      So these long drive heads live on the edge of failure – they are thicker in the face than what all companies make for regular golfers so they don’t break on the first hit by a long drive guy. But they are not so thick that the COR would be so low that the long drive guys lose distance. Hence these heads for long drive guys tend to not last very long before they cave in or break.

      They are NOT, I repeat NOT a good choice for any regular golfer to use because a thicker face with a lower COR will also rob all golfers of distance over a head that has the maximum allowed COR under the rules of golf. But on the other hand, I would bet the farm that you would not be able to buy one of the actual heads made for the long drive guys with their slightly thicker face. The companies that make these models would keep those heads for long drive guys separate, specially made, while the ones they sell to regular golfers would have a normal, thinner face.

      As to no scorelines on drivers, virtually every company skips the use of scorelines across the center of the face on all their Ti driver heads. We do. So this is NOT a thing done for long drive competitors’ driver heads. This came about originally when we all were not as good as we are today at controlling the strength of the titanium faces on driver heads. In those old days we felt if we put scorelines on the face, that would weaken it to the point of it fracturing or caving in sooner. Not so today though. Scorelines could be put on the faces of titanium drivers and the faces would not be weakened to the point of worrying about cave in or fracture.

      The reason you still do NOT see scorelines on driver faces today is because many golfers are so paranoid about hitting their drives with too much spin. Golfers also associate scorelines with spin. So if a company made their titanium driver heads with scorelines across the impact area, many golfers would not buy those heads because they would fear this would cause too much backspin on the shot. And while the effect of scorelines on a driver would be quite minimal on spin, it’s too difficult for the golf companies to try to educate golfers about this fact – so it is just easier for them to not fight this and to keep making driver heads with no lines across the middle of the face.

      TOM

  5. Head sizes will reduce when the manufacturers run out of marketing ideas for the 460 cc models. Then, low and behold, the line will be that they are aerodynamically superior, i.e. less air resistance. I took years to get used to Big Bertha and now drivers are larger than the big plastic ones we played with as kids in the ’60s.

    • Brian

      Head sizes will reduce when two things happen, 1) when the focus groups that all the big golf companies convene to assess the opinion of the golf market tell them that they would be interested in smaller heads. 2) when some other company takes a chance and markets a smaller head and finds that golfers will buy them, at which point all the companies will follow. These companies put tens of millions of dollars in marketing behind a model to drive demand. Before they do that they want to have as much assurance as possible that they can actually generate demand, which means they have to get some feedback that golfers are going to be receptive to the model. Right now, way too many golfers still believe that “bigger is better”. Whether that’s right or wrong, it’s what most golfers think, which means that tens of millions of dollars in marketing may not be effective in changing their minds. So the status quo of 460cc drivers will remain until the companies smell that golfers are ready to accept something smaller.

      TOM

  6. Hi Tom,

    I wanted your opinion on square headed drivers from a few years ago. Other than their slightly unusual looks (I am fine with how my Callaway FT-IQ looks), the argument that it enabled the manufacturers to place more weight in the right places (deep and perimeter)seems a good one to me.
    Are there really any benefits to a square driver, and was it only timid customers that made the manufacturers drop them from their ranges?

    • Richard
      One of the things we have gotten very good at over the past many years of our research is to be able to know what changes to a golf club really make a difference, and which other ones simply do not. If you listen to all the marketing, it is easy to believe that ALL the changes and “advancements” are earth shattering in their effect on shotmaking. But that’s not the case.

      And this one regarding moving weight around a clubhead or even making a heavier weight head to improve performance is one of these many things that you can see and you can measure, but it will not make any real difference in shot performance for 99% of the golfers.

      Moving weight from side to side on a driver head to alter the draw or fade tendency of the shot can be done, but it requires far more weight to be moved than what any of the driver heads allow you to do. I’ve done this testing and developed such drivers in my past design work so I know without question that you have to be able to move at least 30 grams or more from side to side on a head to be able to even see the ball flight move more into a draw or fade. And most all these drivers that have offered weight movement to induce more of a draw or fade only allow you to move 10g to 20g. Which does nothing to ball flight for 99% of the golfers out there.

      Golfers who need to reduce a slice or a hook through fitting need to rely on the FACE ANGLE of the driver. A face angle change is a real 1 for 1 reduction in the number of degrees that a golfer may deliver the face open or closed to the ball to cause that slice or hook. And as such, it can be verified that based on a carry distance of 200 yards, a change in the face angle of 1* will reduce the slice or hook by 4 to 5 yards. Hence if a golfer slices the ball on average 25 yards of curving ball movement in flight, if he gets a driver head that is 3* MORE CLOSED THAN THE ONE HE CURRENTLY PLAYS, he would see that slice reduce by around 12 yards or so.

      TOM

  7. I often play a mint Cleveland Launcher 330Ccc driver because I like the smaller head. A solid hit goes as far as my Ping G2 460cc.

  8. Hi Tom,

    I’ve been playing with a Cleveland VAS 9.5* driver for years. I’ve tried the newer bigger heads but for me they go way too high and it seems I have more of a fade bias with them. Even though many of them are 1-2 degrees closed I find that I fade them no matter what I do. I play to scratch so I know a good swing from a bad one. When I put my best swing on a 460cc driver with a Matrix Black Tie stiff it goes right and fades right. Same shaft in my Cleveland has a baby fade every time. I get about 280 max with my Cleveland and might get a few more with the 460. But I’ve found that he short grass rules!! Any thoughts on why the 460 behaves this way over my 280cc VAS??

    Thanks for all that you do in answering questions both from a technical point of view and from a personal point of view. By the way, I spent some time talking to you back in the day at Golfworks before they built the new facility. What a great time that was when things seemed so much simpler both in life and in golf.

    Mike

    • MIKE:
      Whenever a golfer reports different performance with two different clubs, the ONLY WAY that the real answer to explain the difference can be known is for ALL of the specs for BOTH of the clubs to be ACCURATELY measured, one at a time, so that each spec can be compared to see what’s different and from that, to be able to know what differences could be causing the performance difference. It’s just not possible to determine that in any other way because there can be a spec here, two specs there, that when different, explain the performance difference.

      On its own speaking only about the size, there is no technical reason why a larger size head would bring about a difference in performance vs a smaller head. Especially when you are talking about an accuracy difference. Head size could account for shot height and spin differences depending on the point of impact of the ball on the faces of the two models. BUt the size won’t on its own account for an accuracy issue. Accuracy differences are explained from differences in the lengths, lofts, lies, face angles, shaft weights, shaft flexes, shaft bend profiles, swingweights and grip sizes. Not the size of the head. So here again, to REALLY answer your question without any doubt, we’d have to have both clubs to look at each and every spec, one at a time, and then the answer can come forth. If you had a week or so to be able to be without the two clubs such that you could send them to us, we can do that in about an hour or so and let you know what we find and then get the clubs back to you totally intact and with no changes from how they are now.

      And I do hear what you say about things being more simple in the past in all ways!! Thanks so much for your interest and for your support !!

      TOM

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