Using Launch Monitors
by: Britt Lindsey - VP 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:
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.
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.
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.
Sample computer readout of Launch Angle evaluation data.
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