By Britt Lindsey, Vice President of Technical
Services
You can't open a golf magazine, look at a golf website, or shop
in many of the golf catalogs without coming across an article or some kind of
information related to Launch Angleand Driver Performance. In fact, the latest
release of a new driver by one of the big name brand golf companies features a
weighting system that is specifically designed to manipulate not only launch
angle, but directional control as well. Distance and directional control are
the two most important things most golfers ask for in a driver, in that order
(although I would argue that directional control is the key to lower scores).
So, distance is king and if you believe everything that is being said, launch
angle is the key to maximizing distance. If that is true, what is the optimum
launch angle?
First, it is important to realize that for every swing speed and
loft angle there is an optimum launch angle that will produce maximum distance
- the problem is, there are so many variables it is impossible to guarantee the
optimum launch angle will occur on every drive for any golfer. It is also very
important to understand the relation ship of club head speed to launch angle
and the distance a golf ball will travel. And, it is important to understand
the different types of flight the golf ball can actually achieve. The whole
idea of optimizing launch angle to maximize distance is nothing new. In the
book " The Search for the Perfect Swing" Alistair Cochran and John
Stobbs observed "Increasing the angle at which you drive the ball off will
add to the distance it goes only if you do it without either reducing the
ball's speed off the clubface or increasing its spin." We can draw from this
that a player that swings the club with sufficient clubhead speed
("without... reducing speed") can increase distance with a higher
launch angle ("Increasing the angle") and lower spin
("without... increasing spin").
The key point here is that any increase in distance due to
launch angle and spin is dependent on the clubhead speed. Lower swing speeds
benefit from more spin, not less spin, to help optimize trajectory and flight
time for increased distance, due to the lift that the spinning ball generates.
The technology for measuring spin rates and launch angles has really come a
long way since the 1960's and now is available to almost any golfer who seeks
it out. However, it is important to understand that the High Launch, Low Spin
craze is not for everyone. In fact, it doesn't even apply to most golfers. Yet,
we get information that leads us to believe that specific driver heads, based
on mechanical testing or computer modeling, will produce specific launch angle
characteristics or have a specific launch angle profile for any golfer that
tries it. That's simply not true!
The Facts Are:
1.
Higher launch angle and lower spins rates can produce longer
carry distances for players with swing speeds in excess of 85-90 mph. It takes
this speed, at a minimum, for the golf ball to achieve an aerodynamic flight.
Aerodynamic Flight is controlled by aerodynamic forces such as lift and drag,
and by gravity. At the higher swing speeds, lift and drag forces of the golf
ball actually give the ball a "gliding" element. However, the reason
for the desire for High Launch and Low Spin for higher swing speeds is this:
Higher spin generated at higher launch angles and higher speeds will make the
lift force and drag created work against the forward line of flight momentum
(i.e., distance). Ballistic Flight is the other kind of flight a golf ball
achieves. It is basically controlled by gravity alone.
2.
Swing speeds below 85 mph will benefit from a high launch angle
and a high spin rate. The reason - the more spin, the more lift generated, which
can help the ball stay in the air longer and carry longer. At these lower
speeds, the drag and energy lost in creating spin are offset by the improvement
in distance caused by the increased time in the air.
3.
The loft of the club is only one of many factors that effect the
launch angle and ultimately the total distance a player can hit a driver. Other
factors are: tee height, ball type, shaft type, weather conditions, turf
conditions, ball position, face material, the materials characteristics, face height,
vertical roll of the face, ball contact point on the face, and the center of
gravity location of the head. If you look at turf conditions, hard and dry
verses plush, a high launch scenario may not be the optimum. Where there is a
condition for a ball to roll,the desired launch conditions to maximize distance
change, sometimes dramatically. In conducting launch test with players, the
data gathered can give insight into how to optimize distance. But it must be
understood that many shots are required to gain a pool of data before any real
conclusions can be drawn. It must also be remembered that unless the player
being tested can achieve very consistent contact and swing speeds, the results
will vary a lot from shot to shot. Another point to make here is that in
robotic testing, although repeatability can be achieved in the contact point
and clubhead speed, the swing of the robot does not simulate that of the
majority of golfers. Even if the robotic swing could be made to emulate most
swing types, few golfers could approach the repeatability of contact point and
clubhead speed. Therefore, data based solely on results from robotic testing do
not indicate what will happen in the real world.
Launch monitors are
useful tools in evaluating real golfers, on any given shot, to determine if the
launch conditions and spin rate are within the parameters needed to optimize
distance. However, fitting the basics of loft, club length, shaft weight and
flex, and observing trajectory, ball flight characteristics, and the understanding
of a player's ability and needs will achieve a fit that optimizes distance and
direction control. Launch monitors are a great addition to the fitting process
but are not a be-all, end-all method for fitting or determining driver
performance.
I hope this
information will help you understand what effect launch angle and spin rate
have in determining the performance of a driver. Also, I hope you now have a
better understanding of the benefits and limitations of launch monitor testing
in determining the right driver for any given golfer.