Drivers: Gear Effect in Titanium vs Persimmon

I sure miss the sound of persimmon. I was reading an article you have online that said when we use titanium we lose the gear effect that persimmon offered. Is that true?

Also, will the oversize wood heads provide any advantage? I am not a big hitter (230ish) so I would guess that the COR and other benefits of the new titanium drivers offer distance advantages. I play a titanium 450 cc driver and only 43.5″ shaft for control. Thanks for your book, Just Hit It.

–Bob, Virginia


I am pleased you enjoyed my first book “Just Hit It”. It was fun to write and allowed me to express some of my philosophical beliefs about our wonderful game. Our latest book is “The Fundamentals of Putting,” an instructional book which will walk you through the fundamental mechanics – based on scientific principles — allowing you to know why you are putting well — if you are — or to help you do so if you are not.

Reference persimmon vs. big titanium drivers; I too miss the sound of persimmon but I can tell you that the gear-effect is alive and well with the big titanium heads.

These large heads have a higher MOI (Moment of Inertia) than the smaller woodenheads and thus do not twist as much on off-centered impacts. It is this twisting of the drivers and even fairway woods, on off-centered impacts, that cause the gear-effect. It still happens, but not as severely with the big titanium heads

To explain the gear effect, imagine two meshed gearwheels (cogs) – a small one representing the ball, and a big one representing the driver head. If the centers of these two cogs are on the same line as the head path, then you will have sweet spot impact and there is no twisting of the head (big cog) during impact. If the small cog (the ball) is NOT on this line – e.g. a toed shot – then the big cog (the driver head) will twist in a clockwise direction making the small cog twist in a counterclockwise direction. This is the gear effect. In the case of an impact on the toe of a driver, the ball will have sidespin and the flight will be a slight draw. Similarly, an impact on the heel will result in a slight fade 🙂 – not a duck hook or a banana slice 😦

The same phenomenon works on impacts up or down the face taking away some backspin on high impact points, and adding backspin on low impact points. The difference in total backspin could be as much as 800 rpm or more depending on how high or low impact is on the face.

Let me assure you that as handsome as some persimmon heads are they deserve a place on your mantelshelf rather than in your bag.

The high MOI of the titanium driver heads and the higher COR (Coefficient of Restitution) will really help you. Because you are using a 43.5 inch driver you will improve your accuracy and in most cases, you will hit the ball farther taking advantage of sweet spot impacts. Some of the longer drivers — up to 47+ inches – should be sold with snakebite kits.


Please let us know how the new technology in titanium drivers has helped your game. Make a comment by replying below.

6 thoughts on “Drivers: Gear Effect in Titanium vs Persimmon

  1. Thanks, Frank, that clears up a lot.
    Those of us who acquired whatever skills we have in the years before perimeter-weighted irons and hollow-headed metal woods learned a different game. I never tried to hit a straight shot, relied on my ability to draw it with ease and fade it when necessary. Ever since I used my first “Pittsburgh Persimmon” my game went downhill. Playing with the very perimeter weighted Ping Eye2 was a nightmare.
    The final blow was the advent of the quality solid ball. Not having a heavy center of gravity, but rather a weight evenly distributed within the core means the little suckers just don’t spin much, compared to a balata ball.
    What all this means is that the game has become HARDER for players like me who were never strong enough to be considered long hitters.
    I still have my old Citation driver and 3-wood (with the brass back-weight that provides even more gear effect) and Wilson Staff ‘Fluid Feel’ irons, with the sharp leading edge. But I can no longer generate enough clubhead speed to spin the long irons, especially with the modern ball.

  2. I have noticed 3 changes in titanium versus persimmon driver heads. Whether these observations are solely due to titanium, or are part of the a synergistic combination of titanium heads and longer graphite shafts, I’m not certain.

    (1) I am able to hit the ball substantially higher. There is a tree in one of our fairways that I used to have to go around that I can now easily carry. (2) I have much less sidespin with the titanium. When I go back and hit a persimmon driver (just for fun) I find I will hit bigger hooks or slices than with titanium. (3) I’d guess that due to all around factors of weight, length and more optimal weight distribution, I hit the ball farther. At age 66 I still hit it as far as I did at 36 with persimmon.

    Play well!


  3. I still prefer to hit a persimmon. I only use a modern driver if I am playing in a competitive round. If I am practicing or playing a round for fun I will hit persimmon. In fact I still carry a persiommon 4 wood that I use all the time off the tee. With modern irons, I can use a 3 or 4 iron in place of the 4 wood, I just find it more fun to hit a persimmon.

    • Cyd……good for you. I still play persimmon drivers. I’m not a long driver…220 in the heavy northwest, but I hit the persimmon just as far as the titanium. For me it’s just way more fun to hit real wood. I’m not great, just average, but the feel of persimmon is all the difference.. At times I outdrive my balloon swinging friends with it.

      • One more comment. I think the new balls are 90% of all the new distance, not the club. However, the huge ti face is way more forgiving. Still, they sound like kicking a garbage can.

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