It’s common knowledge that wedges should produce spin. It is difficult to find explanations for how the grooves on a wedge produce spin. Most people say grooves increase friction. Does that mean a wedge with extreme friction would be excellent? To find the answer, we built a sandpaper wedge and tested it against a normal wedge.
Researching why wedges have grooves yields a wide assortment of differing answers. Therefore, for this section, we will stick to the cold hard facts. Nearly everyone agrees that grooves were originally introduced to deal with the grass and debris that comes between the clubface and the ball. For example, a club without grooves would perform like racing slick tires. These tires perform exceptionally well on clean dry tracks. However, in wet or dirty conditions particulates prohibit the tires from making adequate traction with the road. This is the same problem faced by golfers. Therefore, club manufacturers have carved grooves into the surface of wedges to give the debris a channel to escape. This is comparable to the patterns on normal road tires. Now, if the grooves just provide more traction then why does the USGA care about the type of edges the grooves have? This is because the grooves provide spin characteristics. Specifically, how they accomplish this is not adequately explained by manufacturers. Nonetheless, there are some solid theories.
My theory is the spin a wedge imparts on a ball has everything to do with the friction the club creates against the ball. Hence, grooves create friction when the surface of the ball encounters the sharp edges of a groove. This contact creates friction and the ball generates spin. The grooves also channel water and residue away from the surface of the ball. However, this experiment is in dry weather so this attribute will not matter. I theorize that the more friction the face of the wedge has, the more spin it will inevitably transfer to the ball. By adhering a textured surface of sandpaper to the face of a wedge the ball will have a much lower launch angle, more backspin, and a shorter rolling distance.
We acquired two slightly used Alister Mackenzie Limited Satin Wedge. Both wedges are 52-degree wedges with the same bounce angle. We attached a piece of 140-grit sandpaper to the face of one of the wedges. This sandpaper was attached with two-part epoxy resin. We chose this resin because normal glues would not withstand the high impact of a golf wedge. We then went to the Player Performance Studio at Haggin Oaks to use the TrackMan system. Utilizing this system, Calvin Carpenter, a teaching professional, hit 3 sets of 3 balls with each wedge. We analyzed the results of the TrackMan and made a determination on the purpose of wedge grooves.
The results of this experiment are incredibly interesting. The sandpaper wedge had 62% more spin than the stock wedge. The sandpaper wedge averaged a spin rate over 10,000 rpm. Likewise, the launch angle for the sandpaper wedge was 21% lower than that of the unmodified wedge. The landing angle for the sandpaper wedge was also less than that of the stock wedge. As for consistency, the sandpaper wedge again came out on top.
Our conclusion is that friction has a direct relationship to spin. Increasing friction increases spin. Our high-friction and grooveless wedge performed better than its stock counterpart. This strongly supports every point in our hypothesis. While the sandpaper wedge may be inferior in very wet or high debris situations, in dry conditions it is unarguably superior. However, on our ninth swing with the wedge, the sandpaper tore. Additionally, because we used a strong two-part epoxy it would be difficult to replace the sandpaper with a new piece. It would require a more durable design for this to useable on the course. Nonetheless, this experiment hopefully shed some light on how a wedge works.