Drivers are "interesting" because:
In my opinion, the driver is the first place to consider graphite
even if you wouldn't have them in any other club. The reasons are based
the two factors above:
- They are always played off a tee, and
- They are the only club where maximum distance is THE
- Since maximum distance is THE consideration, it pays to
lightweight components. Go for the lightest swingweight you can control
and, keeping the components light, pad out the length of the club to
- Of course, stick with a club length you can control. If
you reach your maximum length of control before you're up to the
swingweight you can control, then you can start adding weight back into
- If you need to add weight, weight added in the shaft
increases strength and/or torsion resistance, or decreases cost.
- If you need to add weight, weight added to the clubhead
increases momentum transferred to the ball at impact (that is,
- Where you choose to add weight will affect the balance point of the
club. Adding weight in the shaft will raise the balance point, while
adding weight in the clubhead will lower the balance point. There is a
mostly untested hypothesis around (Monte Doherty's MOI Balance Index -- MBI) that
might be restated as: raising the balance point promotes a draw while
lowering the balance point promotes a fade.
But doesn't adding length to the shaft put changing
requirements on the lie
angle of the clubhead? Well, yes. And frankly, few component clubheads
flat enough lie to accommodate as much as one inch of extra length. I
none that will handle two inches and still lie properly. Still, the
lack of loft of a driver means that lie angle error does not contribute
a lot to the simple directional error of the face. That only happens if
you scuff the ground before your clubhead gets to the ball. Note that:
- The ball is sitting up on a tee, so the scuff probably
won't happen in the area of impact.
- But... for maximum distance, you should be hitting the ball
on the upswing. That means that the bottom point of the swing should be
several inches behind the ball -- before impact. So an early scuff is a
For this reason, I like a V-sole or keel sole driver. It is
the ultimate in
sole "rocker", If you scuff the ground at the bottom of your swing, the
contact is directly under the center of gravity even if the lie angle
wrong. This advantage is not theoretical; I have seen it work for me
others for whom I've built drivers. A fat hit with a keel-sole driver
little distance, but surprisingly little and it still goes straight.
Keel soles used to be common in the 1990s (the original Callaway Big
Bertha had one, and the feature was widely copied). But driver heads
today have twice the size (460cc instead of 230cc), and I don't know of
any with keel soles.
Lets look at all the clubhead features that have been sold as
improvements, and evaluate how much of an improvement they really are:
- Jumbo clubheads
- The USGA and R&A rules have limited clubhead volume
to 460cc. This is much bigger than drivers were in the 1990s when this
page was first written. Today, almost all driver heads on the market
push the 460cc limit. This increases the peripheral weighting, which
them more forgiving. They also give more confidence to some golfers,
though they are negative images to other golfers. They do have one
danger: increasing size without increasing weight results in a weaker
structure. No responsible designer would make the clubface
substantially weaker, so the sole and especially the big, rounded crown
of the clubhead is made weaker instead. The result is increased danger
of denting it in handling (not in the normal use of hitting the ball),
only cosmetic for most dents, but not all. Another problem with
maximum-volume heads is air resistance possibly hurting clubhead speed.
Which brings us to...
- Aerodynamic clubhead shape
- There may be something to this, but I'm a skeptic. Until a
rocket scientist (literally) comes along and explains it to me, I'm
going to believe that spoilers, turbulators, and airfoil shapes are
advertising gimmicks. Mostly, but perhaps not completely. I have done a
back-of-the-envelope calculation, and here is what I concluded. (Bear
in mind that I am an engineer. I know the fundamentals, but I'm far
from an expert on compressible fluid flow, which is what this is about.
My study was slightly more than scribbles on toilet paper; it did
involve solving a differential equation in Excel, but it was nowhere
near what an expert could do.)
- There may be as much as 4mph of clubhead speed lost to
air resistance by a maximum-volume driver swung to an impact speed of
- I doubt that much more than 1mph can be recovered from
that by aerodynamic shaping of the clubhead, but lets say 1.5mph to be
- That would provide an extra 5-6 yards at most. Not to
sneeze at, but not to spend hundreds of dollars on either IMHO.
- This is a biggie. Since I first wrote the Club Design
Notes, more and more players are "lofting up", and driving distance is
still going up. In the 1990s,
John Daly could generate enough clubhead speed to get his huge
from a 7-degree clubface. But today's big hitter, Dustin Johnson, uses
a 10.5-degree loft. And most of us need more loft for our maximum
distance. Here's a table I put together using TrajectoWare Drive software.
for Maximum Distance
For a serious technical discussion of how loft affects
driving distance, I have a detailed
article on the subject.
With the arrival of super-jumbo titanium and 15-5 steel
it was possible to find unusually large
lofted clubheads that were
intended to "go with" these big drivers. (Unfortunately, these are hard
to find today.) For instance my wife has a
very slow swing. Her "driver" is a super-jumbo 5-wood with a 200cc
-- easily the size of the "jumbo" driver of the mid-'90s. It's a very
easy hitting club, and gets the ball up in the air even though her
clubhead speed is very low.
OK, digression for a true
story. In the mid-'90s, we visited my wife's aunt in
Florida. She lived in a senior community with an executive golf course,
and played golf almost every day. She was very athletic when she was
younger, and was frustrated because her senior friends were hitting
good drives while she was hitting short worm-burners. I looked at her
driver and asked her, "What made you buy this?" She told me a good
golfer in the community had gone to advise her when she bought her
clubs. He knew that the Taylor Bubble was a great driver and they had
this one at a great price; he told her to get it. Well, it had a loft
of 9.5°, and here is a lady in her 70s trying to get it off the tee. I
told her to try my wife's tee club, which I made for her from a 21°
big-head 5-wood. She immediately started hitting drives better and
farther than her friends. At the end of the week, my wife's club stayed
in Florida, and I had to make her another one. (I did take a 9.5°
Bubble home, with her blessing. It's in my garage somewhere, I'm sure.)
So consider the golfer's swing speed -- and accuracy --
carefully in choosing a driver. Unless you're talking about a low
handicapper with a lot of clubhead speed and the ability to square the
clubface well every time, the best loft is probably several degrees
higher than you would have guessed.
- Face angle
- Every metalwood head has (or should have) a specified face
angle such as "1 degree open", "2 degrees closed" (or "hooked"), or
"square". I don't believe that selecting a face angle is the right way
to treat a golfer's slice or hook. Tom Wishon of Golfsmith disagrees.
You're welcome to decide for yourself.
- In my 2008
technology forecast for the golf industry, I projected that a
significant advance in solving the combinatorics problem in
clubfitting. The fitters would not need to stock a club with every
possible specification; some of the specs might be adjustable, and some
of the components might be interchangeable. This has come to pass, but
hardly limited to a clubfitter's tool. In 2017, many of the popular
commercial drivers come with significant adjustability. It isn't clear
that the owners of these drivers are sufficiently knowledgeable to do
effective self-fitting. Well, I'm sure some are, but many are either
leaving it as it came from the store or twiddling it and hoping
something will help.
- There are several adjustments available on drivers in
2017: shaft adapters, adjustable weights,
and hosel angle.
adapters allow you to interchange the shaft attached to
the clubhead. "You" means the clubfitter; at least that was the
original intent. But a lot of commercial drivers today are sold with
the adapters in the heads. If "you" -- this time the owner of the club
-- want to try a reshaft, just have a shaft of the desired model made
your flex with your favorite grip and the adapater for your driver
head. At that point, you can swap shafts back and forth to your heart's
content. And no torch nor shaft puller were ever involved in the entire
can take the form of weights sliding on a track in the sole, or screws
of various weights that screw into various spots on the clubhead. You
can vary the amount of weight (especially with the screws) and the
placement of the weights. There is typically up to 15-20 grams of
weight available for adjustment.
- If you adjust the amount of weight, you have up to
perhaps 10 swingweight points to play with. That's a lot of adjustment
- If you adjust the placement of the weight, you are
really trying to move the center of gravity. The intention is to change
the dynamic loft at impact (which it can do, just a little) or the
spin, due to gear effect. Tom Wishon has long maintained that it takes
30-40 grams of moveable weight to make a significant difference in
spin, and built his adjustable clubs accordingly. My computer
analyses agree with TaylorMade's assertion that even 15 grams
moved from toe to heel can affect ball flight significantly. But -- my
caveat here -- "significantly" is not enough to fix a slice; if you
have a bad slice, you may not even notice the difference the weight
change is making for you.
angle purports to adjust the loft, lie, and face angle.
How does it work? There is an insert in the hosel bore, which has its
own bore for the shaft. But the insert's bore does not share a
centerline with the hosel bore; it is something like 2° different from
the hosel bore. So, depending on the way you turn the insert in the
hosel, the shaft may be leaning 2° flat, upright, rearward, or forward,
or some combination thereof.
Tom Wishon has made a very good video
showing how the adjustable hosel really works.
- It is easy to see how this would affect the lie angle.
Just turn the adapter so the shaft is 2° flat or 2° upright. In
between? Well, you'll have to accept a change in the fore-and-aft tilt
of the shaft, along with the desired change in lie angle.
- If the shaft is tilting fore and aft, that's loft --
right? Well, maybe. If you set up with the clubhead hovering behind the
ball, rather than resting on the ground, then that is exactly loft.
- If you're setting up and allowing the clubhead sole to
rest on the ground in its flattest position, the fore-and-aft
adjustment did not affect loft at all. With the clubhead soled, the
loft is simply the loft built into the clubhead, not the one you dialed
on the hosel adjustment. In order to make this happen, the clubhead
rotates a little to settle into its "soled" position -- so the
adjustment is really about face angle, not loft at all.
- Weight placement
- Completely apart from the ability for the purchaser to move
the center of gravity of the clubhead, consider the ability of the
designer to place the CG in the first place. In particular, it
is desirable to get the CG of a driver as low as possible; if
you doubt this, or want to see the conditions under which it is true,
see my article
on exactly that subject.
Some of the modern driver head designs go to great lengths to lower the
CG. This consists of two steps:
up some discretionary weight, by making the structural
shell (face, sole, and crown) lighter overall. Some approaches to this:
the discretionary weight
by placing it as low in the
clubhead as possible. Usually this is accomplished by beefing up the
sole with thicker steel. It does help the strength of the club as well
as making up the weight low in the club. Another approach is to make
the sole, or part of the sole, out of tungsten, which is more than
twice as heavy as steel. This is expensive; fabricating and bonding
tungsten is harder to do than with steel or even titanium. TaylorMade
did it with the original Rescue hybrid: a thick sole of tungsten and
lightweight crown and face of titanium. The Orlimar fairway woods also
advertised this feature, but it was just marketing. The tungsten
"inserts" were just tungsten foil on the sole weighing a few grams.
- Use a lighter (really, greater strength-to-weight
ratio) material for the shell. Clubhead manufacturers thought they were
doing just that in the 1990s when they went to titanium. Then the race
to get the largest volume of clubhead took over. Today, at the legal
maximum of 460cc, the clubhead needs
titanium just to keep its structural integrity at the 200 grams or so
that a driver should be. But note that Jeff Summitt used exactly that
approach with the XS Titanium 3-wood in 2013. Since a 3-wood
has a much smaller volume than a driver and somewhat larger ideal
weight, that freed up about 80 discretionary grams, and the result is a
very effective clubhead.
- Reinforce the structure of the head in ways that more
weight can be shaved from the shell than you used for reinforcement.
Having seen Callaway's 2017 commercials for "Jailbreak Technology", I
believe that is what the vertical bars are for behind the face. They
prevent the crown and sole from buckling by attaching the crown to the
sole with steel just behind the face. Thereforce, any flex is the face
is just in
the face, not aided by weakness in the shell behind the face.
- Use different materials for different parts of the
clubhead -- strongest for the face (which absorbs a major shock), still
pretty strong for the sole (which may bang on the ground -- but see step #2), and least
strong for the crown (which shouldn't hit anything, unless airling
baggage handlers are gorillas). That is why you see composite crowns on
metalwoods, especially drivers. They can be made light and very thin,
because they need to remain rigid but only under relatively small
- Not a performance improvement in a driver! Square
grooves, V grooves, or no grooves at all: it just doesn't matter. The
ball is compressed on the clubface for long enough so the friction
between ball and clubface results in no slippage by
the time the ball departs. All the spin, in both vertical an horizontal
planes, will be imparted no matter what kind of grooves or non-grooves
the driver has.
fact, grooves may hurt performance. No, I'm not talking about spin,
although much of modern driver analysis says less spin gives more
distance. I'm talking about Coefficient of Restitution, AKA spring face or
trampoline effect. Grooves can limit the strength of the clubface, if
you make the face really thin. So it is easier to build a high-COR
clubface if you leave off the grooves.
Last modified May 17,