Lets be Frank


Visit the Gas Station

What is going on here? A nitrogen-filled driver matched with an ultra-thin clubface whose sweet spot is as big as the face? Can this be true? Please give me your thoughts on the benefits and drawbacks of such a club. Thanks, Frank.
' Dave

The USGA has made some silly and questionable equipment rules changes over the past several years, but when it comes to measuring the performance of a driver with regard to Spring-Like Effect'or, in tech-speak, Coefficient of Restitution (COR)'it is very efficient and will not place on the conforming list of drivers a club which exceeds the limit. Almost all of todays drivers are at or just below the limit.
The COR dictates the ball speed by measuring the efficiency of the impact between two colliding bodies; in this case, the driver and the ball. If this exceeds the limit at a specific clubhead speed then the club is considered non-conforming and will be placed on the non-conforming list.
If the COR is at the limit, the club cannot generate more ball speed than other clubs at this limit for the head speeds used to test the club. If you want to know if this club conforms to the rules, rather than wade through the listings, call the manufacturer or better yet call the USGA at 201-234-2300 and ask for the Test Center.
Hope this helps. And, should you purchase one of these drivers, remember to go to the gas station to fill up your driver before each round.

Increase Speed with Swing Weight?

Thanks for your information every week. Theres nowhere else that we can get this kind of help. Keep it coming!
I am aware that swing weight is dependant on the weight of the clubhead in relation to the grip end, therefore my question:
I just went from a swing weight of D5 and D6 in my old TaylorMade clubs, with Dynamic Gold S300 shafts, to D4 in my new Mizuno irons that have a new 103-gram graphite shaft. Will my swing speed increase and affect my distance because of the swing weight reduction and'I presume'the overall weight of the new clubs?
' Don

Thanks for your comments about the weekly column. It would be good if you can get as many of your friends as possible to sign up as Frankly Friends, so we can help grow the game and persuade the USGA to consider the vast majority of golfers when making its rules changes, instead of an elite few.
As far as the difference in swing weight from a D6 to a D4, I can assure you that you will not be able to detect any difference in performance. Some of the best golfers in the world are not able to detect a change in performance of a two-point change. You will find a significantly greater difference in performance between the two sets of clubs than in their swing weight.
Swing weight is a static balance, and based on the amount of weight needed, hung from the very tip of the clubs grip end to get it to balance on a sharp edge (fulcrum) positioned at 14 inches from the end of the grip. As you can imagine, a heavier grip on your club will require less weight added to its butt end to get it to balance on the scale. So this small change will alter the swing weight
Similarly, if you wear a glove, this is the same as if it were part of the grip. Wearing it on your hand or wrapping it onto the grip makes no difference except to the swing weight scale. A glove on a grip (or on your hand) will decrease the swing weight of the club by about 5 points. Going a little further, wearing a wristwatch will also change the inertia of the system'equivalent to changing the swing weight of the implement'which dynamically includes your hands.
The bottom line is that swing weight is a good guideline in matching clubs, provided its not abused by counter weighting. Swing weight and overall weight have been successfully used for some time to match clubs, but it is a static balance and not a dynamic one as the name implies, so a couple of points difference is nothing to be concerned about from one set to another.
Good luck with your new set.

Please note: By submitting your question to Frank you will automatically become a Frankly Friend so you can stay up to date with his golf equipment Q&A. You may unsubscribe at any time.
Frank Thomas, inventor of the graphite shaft, is founder of Frankly Golf, a company dedicated to helping golfers. Frank is chief technical advisor to GolfChannel.com. He served as technical director of the USGA for 26 years and directed the development of the GHIN system and introduced the Stimpmeter to the world of golf. To email a question for possible use in an upcoming Let's Be Frank column, please email letsbefrank@franklygolf.com
Frank Thomas