# Driver Head Weight and Club Length

Dave Tutelman -- October 28, 2012
This has been a hard article to write. Danny Seng asked a question on Spinetalk, and I promised to look at it when I had the time. The day after I started work on it, Hurricane Sandy hit coastal New Jersey and I was without power for three days. In fact, I was doing runs with SwingPerfect and TrajectoWare Drive at the moment the lights went out. (We were lucky. A lot of my local friends were without power for a lot longer, some for almost two weeks.)

Then, when I was able to get back to it, I realized (a) that the question was much bigger than the limited inquiry that Danny had made, and (b) the models were giving results that mostly didn't agree with one another, nor did they agree with some of the anecdotal evidence that is around for us to look at. It took a lot of work, additional calculation, and even making and using my own long driver -- and even a second pass at the article after it was posted -- before I was satisfied I understood what was going on.

What is the best clubhead weight for a driver, the weight that gives the best ball speed? Actually, that is the question that originally got me into golf analysis in the early 1990s. I recognized the tradeoff that:
• A heavier head will probably result in less clubhead speed, but...
• A heavier head at a given clubhead speed will definitely transfer more momentum to the ball.
So where is the balance between speed and mass?

I did quite a bit of forgettable mathematics on the problem -- remember that this was my first foray into golf physics -- before discovering Cochran and Stobbs' excellent book. The answer was there. The problem itself is obvious, and had been solved before the book's first publication in 1968.

In this article, we look at various approaches to using clubhead weight (sometimes in conjunction with club length) to get the maximum distance out of a driver.
• Change the clubhead weight and keep everything else about the club the same.
• Physical reasoning says we might get more distance if we change the club length, as we change clubhead weight to keep the club feel the same.
• Bernie Baymiller's use of lighter heads and longer shafts.
• An overly simplistic computation, to give an optimistic estimate (upper bound) on how much we might gain.
• A more precise computer simulation study, with variations of length and headweight for constant MOI, variation of length alone, and variation of headweight at the maximum legal length.
• What (if any) swing changes are necessary to assure that the clubface is square using the longer driver?
• A comparison of studies of the longer driver.
• Finally, let's look at empirical experience, mostly anecdotal but a few careful studies as well.
• It may be difficult to manufacture high-quality driver heads at less than about 190 grams.
• A few clubfitters who have experimented with lighter heads, especially to allow longer drivers, conclude that lighter and longer drivers give much more advantage than my studies say. But more clubfitters believe that it takes a great deal of skill to consistently get satisfactory results from a longer driver, more skill than most golf participants possess.
• And speaking of professional competitors, what about the sport of Long Drive? We see a lot of longer clubs there. I have opinions from some prominent LDA competitors.
• I went ahead and added my own anecdotal evidence. I built myself a long, light driver and tried it on the course, as well as taking detailed data using a launch monitor. Perhaps it is reassuring that my performance was more like the computer model. And I learned a lot in the experience.
My conclusion is that the longer driver works for some golfers, but certainly not all. Analysis and some experience show that there is a potential gain of perhaps 10-15 yards for those who can hit the sweet spot consistently. Unfortunately, if you can't do that, you will lose distance on average, not gain it. There are those that claim gains much more than a dozen yards, some more than 30 yards; they either incorrect in their estimates or are swinging the club quite differently than their normal-length driver.

Last updated Jan 18, 2013