The Driver Sweetspot and Center of Gravity
In the first two videos in the "Bomb Your Driver" series I discussed the extreme importance of hitting the ball on the sweet spot of the driver and understanding the true loft of your club.
In this next installment, prepare to have your eyes opened to the truth about the so-called driver "sweet spot". This term gets loosely thrown around a lot and there is a lot of misinformation out there. So to start, let's dispel some myths about the driver sweet spot that the club manufacturers would like for you to believe.
Myth Number 1: Our new “XYZ” driver has an "enlarged" sweet spot.
The true sweet spot on a driver is the size of a pin point and simply CAN'T be made any bigger. There is only one true sweet spot on any driver where you will get maximum ball speed and no twisting of the driver head at impact. Missing this spot by the tiniest amount imparts sidespin on the ball and costs you ball speed and distance.
In actuality, what these manufacturers are referring to is that their drivers are more forgiving in that when you do miss the sweet spot you will lose LESS ball speed and the club will twist LESS due to a higher Moment of Inertia, or MOI.
Myth Number 2: The sweet spot on a driver is in the exact center of the clubface.
I really wish this were true, but as you will see in this video, the sweet spot position varies dramatically from model to model and is often not in the exact center in the face. In most modern drivers, the sweet spot is close to the center from heel to toe, but vertically, it has moved to a position above the center of the face.
This has happened as club designers have been able to move discretionary weight from the face and crown to places lower and deeper in the head due to the use of lighter and stronger modern materials. This weight moves the Center of Gravity (COG) lower and further back which moves the sweet spot higher on the face.
As I discuss in the video, this causes some significant and complicated issues when it comes to optimally fitting you for the perfect driver.
To demonstrate this in the video, I have the heads of 5 different drivers pulled from the shaft. If you don't pull the head off your driver, you have no way of determining the exact sweet spot of the club.
So, you have no way of knowing exactly where your driver needs to be struck to produce the longest, straightest shots. But, if you do pull the head and check the COG, you will likely find that it is higher than the center of the clubface and often will tend to be more toward the heel. Why does this matter? Simple.
The max Coefficient of Restitution (COR) on your driver IS in the center of your clubface because the face will flex the most at the intersection of the X and Y axis as this point is the furthest from the edges of the face. In other words, your sweet spot and point of maximum COR often don't line up! I discuss this in detail in the video, so don’t worry if it’s not totally clear just yet.
If some of you are confused about this, think of it this way. The face will simply flex less closer to the edge of the face because it's supported more by the surrounding metal. It's the same as bouncing on a trampoline in the center vs. near the outer edge.
We need the face to flex as much as possible at impact to absorb some of the ball compression to achieve maximum ball speed. That's right, we can actually “over compress” the ball and lose energy transfer, and thus ball speed and distance. Max COR doesn't "spring" the ball forward because the face acts like a trampoline.
In fact, the exact opposite is true. The face needs to deflect so that we can transfer maximum energy to the ball. Think of it as if hitting a marshmallow. It's not going to go very far because all of the energy of the blow of impact will be absorbed by the marshmallow. When the face absorbs some of the energy, more ball speed is a result as there is more efficient energy transfer.
So, now back to this little problem of the COG and the spot where we achieve max COR are not inline. In other words, we basically have two sweet spots and neither is perfectly "sweet". We also have the potential problem for many golfers with above average clubhead speed that the COG sweet spot is in a place where there is more loft than needed for optimal launch conditions.
When you start to realize just how complicated things can get, it becomes very clear that the chances of you buying a driver off the shelf and it being a perfect fit for you is about as realistic as you winning the lottery without buying a ticket.
Notice the image of this Titleist 983K driver with 9.5° of loft stated on the sole of the clubhead. Now notice the two dots on the clubface. Can you guess which is which? The red dot represents the place on the clubface where the loft is actually a true 9.5° as measured with a loft gauge. You see, Titleist isn't lying to you that this driver has 9.5° of loft. It's just that where that 9.5° is on the clubface is absolutely useless unless you are trying to hit the ball at a gopher.
Now, notice the black dot. The black dot is much higher on the face and off-center toward the heel. This dot is where the exact sweet spot is located on the clubface as measured in the video. This is the only place on the face where you can get the COG directly in line with the ball at impact.
Unfortunately, it is not located in the place where you would also get the maximimum COR. Not only that, but at this point, the club has 11.5° of loft, NOT the 9.5° stated on the face. For the average golfer, that is a good thing because they need more loft. But for someone who needs a true 9.5°, this driver will spin far too much and cost that golfer some serious yardage.
It is possible to move the sweetspot of any club with weighting, but you then run into other issues that will be discussed later in the series and are outside the scope of this discussion. For now, learn and understand your sweetspot and how it is probably costing you distance!
I highly recommend Tom Wishon's "The Search for the Perfect Golf Club" if you are interested in getting into some of the more technical details of this topic.
If you would like to learn more:
Checkpoints for Practice
- The "sweet spot" on any club head is the center of gravity - it is single point, not a whole area
- Find the center of gravity by balancing the head on a point such as a pen - it's probably not in the center of the face
- The sweet spot gives maximum ball speed & minimum spin
- However, when the sweet spot is off center you lose COR, which can reduce ball speed
- The center of gravity can be changed with rat glue or lead tape
Video Transcription: Golf Driver Sweet Spot
For the third video in the Bomb Your Driver series, we're going to talk about something that's very, very important and, unfortunately, very misrepresented by a lot of what you read in magazines and what you see in commercials. That's the sweet spot of the driver head.
With all the super, highly competitive companies out there now who are competing for your big bucks on drivers that are costing $400-800 anymore there's a lot of money at stake, so these companies are positioning things as best they can to make it seem like you're going to get a lot of benefit from a driver, and there's a lot of hoopla around it that's not exactly true.
Today I'm going to dispel a lot of those myths. One of those is the sweet spot.
When you look at a driver, typically there's usually a score line on the top that's showing you where they want you to hit the ball and some score lines on the face so you know exactly where they're showing you the sweet spot is.
What's misrepresented a lot of times is the actual sweet spot. There are golf ads out these days that say that the sweet spot is enlarged, that they have a bigger sweet spot. Unfortunately, the truth of the matter is the sweet spot is tiny; the size of a pin dot.
There's no enlarged sweet spot on any club face, whether it's an iron, a driver, or what have you. The sweet spot is simply the size of a dot. If you look closely here, you can see that I've actually drawn a dot on here where the sweet spot is.
The question that you're asking yourself is, "How does he know where the sweet spot is?"
I've done it by balancing this driver head on a point here. I've actually got a pen set up vertically to make sure it's level. It's set up in a vice here. You can actually balance any driver head on the sweet spot or the center of the club face, which is going to help you determine the center of gravity for that club.
You can balance it both on the face and on the sole, and by doing that you'll find exactly where the center of gravity is.
In the modern driver, what you've found is that the center of gravity from the front to the back of the club head has actually moved deeper and deeper and deeper. At the end of the day, it's going to help you launch the ball higher because it's going to help the shaft actually bend forward more at impact. We'll talk about that again later.
For now, what we need to really understand is that there are a couple of things that, once you determine where the sweet spot is, dramatically impact how that driver is going to play for you.
One of the things that we talked about was the actual true loft, where you need to strike the ball; the roll on the club face in the last video, and how that affects the loft and where you're going to strike the ball on the face.
What we're talking about now is that once we've actually balanced this driver head on this pen, we mark that spot. What I need to do now is determine what that loft is at the sweet spot.
First of all, why is the sweet spot that important? Well, it's simple. The sweet spot of the club is the only place that you can hit it on the face that's going to give you, one, maximum ball speed; that's where the mass is directed directly behind the ball.
Two, it's going to have no twisting. If you strike it off the toe, the club head will twist a little bit. If you strike it off the heel, the club head will twist a bit. What that does is lessen the blow, so you don't get as sharp a blow, so you lose ball speed there.
Then, two, the twisting imparts side-spin. Now when the ball's spinning, obviously off line, we're going to lose accuracy and distance as well.
Once you know where the sweet spot is, it's very, very important to know how to utilize that and set up the driver properly for you.
I have in my hands here a Ping G5 club marked 7.5° on the sole. You know from the last video that just because it says 7.5° on the sole doesn't really mean anything. Not only are there manufacturing tolerances that allow the driver to have more or less loft than what's stated on the sole of the club, but there's also the roll.
When we're looking at the effective loft of the club, it's usually very different. Once I've taken the time to mark the sweet spot on the club here, which I have with this black dot, I've gone in using the loft gauge and I've actually measured what the loft is on the sweet spot of the club.
In this case, this 7.5° driver, the loft on the sweet spot where I need to hit it is 9°, so if I hit this driver the absolute best that it can possibly perform, hitting it a little bit higher on the face, it's actually 9°. That may or may not work for your swing characteristics.
Maybe you need more loft, maybe you need less loft, but until you get on a launch monitor you won't know. Until you start to investigate what the clubs that you're using are actually set up for, you won't know.
I've got another club here to illustrate this. I've got a Geek Golf Dot Com; this head hand-picked, it's 7.5°. I've set it up, I've determined where the sweet spot is and I've got it marked here. It's also higher on the face, and this loft is actually 10°.
This has more roll than the Ping, so to use this club at its absolute maximum capability to get the best ball speed out of it, to get the center of gravity directly behind the ball with no side spin and hit a perfect, straight shot, the loft is actually 10° on a 7.5° head.
Now I'm running into all kinds of issues where I thought I bought a 7.5° head, and I did, but the 7.5° of loft is way down here. But the sweet spot is actually way up here. What's going to happen is a vertical gear effect is going to take place and I'm going to get more spin hitting it lower on the face than I would hitting it on the sweet spot.
Now we're running into a lot of complex variables that are very, very important in determining how to maximize your driver distance.
There's another issue that we start to run into, and that I'll illustrate with another head here. I know you can't really see this very well, but I've marked the sweet spot here. It's higher on the face than the center, and this one tends to err a little bit towards the toe.
This is a Nakashima Htec head, and what you'll find here is that now we've got another issue coming into play. It comes into play with the other drivers that I've got here as well, that once the sweet spot is no longer in the exact center of the club face, we're losing COR.
That coefficient of restitution that everybody has heard so much about; what is this COR thing? Why is it 0.83? What does that mean?
Long story short, what happens when the ball strikes the face is the face actually deflects. It actually caves in a little bit, and what that does is it actually absorb some of the blow to the ball, so that the ball doesn't compress like a marshmallow.
A lot of people think that what you want it to do is compress the ball a lot and that gives you more ball speed because the trampoline effect, as the face gives, launches the ball faster. It's simply not true. The exact opposite is true, actually.
The reason that the COR of the face is important is because you actually want the face to cave in a little bit at impact, a very small amount. What that does is it keeps the ball from compressing so much that it absorbs all the energy of the blow.
That may not make sense at first when you think about it. You would think you would want it to be as hard as it could, but think about hitting a marshmallow. If you hit a marshmallow with a golf club it's not going to go anywhere. The simple reason is, the marshmallow is soft. It's going to absorb all the energy and it's just going to smash on the face.
The golf ball too, because it's relatively soft, is actually going to compress a lot as well. What you want to do is actually absorb some of that with the club face giving in, and that allows you to transfer more energy to the ball.
That's why that's so important. When we determine the sweet spot is higher or lower on the face, if we look at any of these faces here that are marked with the little dots where we've marked the loft and the sweet spot on here, it's no longer in the exact center of the club face.
Now we've got it actually moved higher on the face. If you find some that tend to err towards the heel a little bit - and this is very common now, because a lot of club manufacturers are moving weight to the heel to make it easier to fight a slice because the toe will turn over a little bit faster through impact if there's more weight in the heel. This is going to help the average golfer, who tends to slice the ball.
Now we've got issues where, if the sweet spot is moved over toward the heel even a couple of millimeters we're not going to get maximum COR.
Long story short, where the center of gravity of your club face is, is extremely important to getting the maximum launch characteristics for your driver.
The trick is, you can actually change this position. You have to pull the head off the shaft to determine this. You can put it on a pen or anything like this that I have set up here. Once you determine where that is, you can actually use lead tape or rat glue or those types of things.
It's best to leave this to your club builder, but if you have a very experienced club builder who understands how this stuff works you can start to maximize it.
Then you can also start to find that, if your sweet spot is a little bit higher on the face and it has too much loft for you; say you're looking for a true 8° of dynamic loft at impact with the actual club head - we're not talking about changing the shafts and those types of things at this point - but your driver actually has 10° of loft. What you can do is put rat glue or lead tape on the head.
Most people use the glue on the inside because it's aesthetically more pleasing, but you can start to move the center of gravity higher and lower, left to right, and those types of things to get the loft that you're looking for at impact, through changing the center of gravity.
Bottom story is, it's a complex subject but the important thing is for you to start to understand that, first of all, the sweet spot is not always in the center of the face.
You may be hitting it right on the screws, where you think it's dead center in the face. One, you may not be getting the true loft that you think you're getting, and two, you may not be hitting it with the proper amount of spin because if it's lower on the face than where the center of gravity is, you're going to get more spin than you need.
For the average golfer it's not such an issue, but for the higher club head speed guys it's a huge deal.
Long story short, don't believe everything that you read, for starters, and also start to do your own investigation on your club heads.
If you have a club builder that can pull a head for you and mark the sweet spot for you, and you start to get an understanding of what the actual loft is on your sweet spot, you're going to have a lot better understanding on how to get maximum distance for your driver swing, for your setup in the future, and that's what you're looking for in helping to maximize your driver distance.