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The Troon Connection: Where the Koehler Sole Was Born

The Troon Connection: Where the Koehler Sole Was Born

How a trip to Scotland stimulated the creation of the most versatile wedge sole in golf.


     As we all watch the best golfers in the world tackle Royal Troon this week in The Open Championship, we at Edison Golf feel a special connection, as this fabulous Scottish links course is where the versatile Koehler Sole design was first put to the test.

     Here’s how Edison Founder/CEO and Director of Innovation Terry Koehler tells that story.


     In 1990, I made a once-in-a-lifetime golf trip to Scotland with my older brother, Fritz. I had been designing putters for nearly a decade but had not yet turned my attention to wedges. Little did I know this trip would have life-changing impact on my life and golf career.

     The trip began with a late afternoon round on the New Course at St. Andrews, where I began to see that my mainstream brand sand wedge was just not well-suited to the firm turf he found there. As our trip progressed through a round at Carnoustie the next day, my frustrations compounded, though I was able to put together a solid round of 73 at “Hogan’s Alley”.

     That afternoon, as my brother and I toured the village of St. Andrews, we stopped into Auchterlonie’s Golf Shop; it was there I spotted a grinding wheel and had an idea. After introducing myself and gaining permission to use the grinder, I returned to the hotel to retrieve my sand wedge and headed back to Auchterlonie’s.

     The vision I had was to grind much of the bounce off the main part of the sole, then grind a very aggressive bounce into the leading 1/3 of an inch or so of the sole. Removing metal almost all the way up to the first groove gave the juncture a crazy look, so I then did considerable grinding at the bottom of the hosel to make it look acceptable at address.

     Of course, after removing all that metal, the swingweight was remarkably reduced, so I purchased some lead tape and began to pack it thickly behind the center of the clubhead. It was pretty ugly, of course, but my vision for the first “dual bounce sole” was prototyped.

     The next morning, we made our trek across Scotland to the west coast, where Royal Troon was next on the agenda. Driving on the left side of the road for the first time was quite harrowing, but we made the trip without incident, though we did have a few close calls.

     Teeing it up on Royal Troon was where this new prototype “dual bounce sole” wedge would be put to the test . . . and it performed as hoped. The tight fairway lies were no longer a challenge, and the wedge performed admirably out of the bunker as well.

     My brother and I shared the wedge and were consistently amazed by how well it handled nearly any kind of lie we encountered. The unexpected ‘bonus’ was the penetrating trajectories and amazing spin, especially on the shorter-range pitch shots, as result of dramatically raising the center of mass (CG) of the clubhead.

     Our caddies were also intrigued and asked where I got such a strange “Igor-looking” wedge. After telling the story about how the idea had come to me in St. Andrews the day before, the caddies each took some shots with the wedge and gave it their full “thumbs up”.

     This new wedge idea continued to impress us through our following rounds at Turnberry and back to the Old Course at St. Andrews.

     Upon my return home to San Antonio, Texas, I began to shift my focus from designing putters to perfecting this new wedge sole design. I would purchase used wedges and grind and weld and test . . . a process that took several years . . . until I felt like I had perfected the design.

     On April 15, 1994, I was awarded U.S. Patent #5,301,944 – Golf Club Head With Improved Sole.

     Over the next thirty years, this design has been continuously tweaked and improved, and has been incorporated into wedges I have created for Merit Golf, Reid Lockhart, Eidolon, SCOR, Ben Hogan and now Edison. It has been known as the “Dual Bounce Sole” and the “V-Sole” by those brands, but at Edison, it’s simply “the Koehler Sole”, and it has earned a loyal following of tens of thousands of golfers through those three decades.

     The simple fact is that the Koehler Sole eliminates the confusion over bounce and grinds and gives you a wedge that never met a lie or swing path it couldn’t handle.


To experience the performance of “the Koehler Sole” and other Edison technologies, take advantage of Edison’s 100% Risk Free Trial – www.EdisonWedges.com.

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