From what I have read and learned, MOI is the measure of the resistance to twisting in the clubhead. What difference does this make when the shaft of a driver torques from 3 to 6 degrees? It would seem that the torque in the shaft would make any twisting in the clubhead itself insignificant.
You are right the MOI (Moment of Inertia) is the measure of the resistance to angular acceleration (twisting during impact). For more on MOI please click here. The time that the driver and the ball are in contact during impact is about .000450 of a second.
To put this into perspective it takes about 0.1 of a second to blink your eye, which means that you may have 222 impacts in this time. If you shoot par that is about three rounds of golf even though contact between the ball and the putter is a little longer than a driver.
During this time there is an average force of about 1,600 pounds being transferred to the ball. This is what is required to accelerate the ball from zero mph to 160 mph in .00045 of a second. During this time the shaft plays no part in the impact. In fact it might just as well not be connected to the club head after the ball and the club first meet. If the ball makes contact with the sweet spot then the MOI of the head is not important. But if you miss this sweet spot then the club head will twist and the rate of rotation is dependent on the MOI of the head and nothing to do with the shaft.
This is a new twist on MOI for some of us.
Hope this helps.
Hello Mr. Thomas,
I play to a 4 handicap and like most golfers would like to achieve more distance with my driver. I have been on several launch monitors and been told different things about where the ball should be impacting the club face to achieve the most distance and performance of the club and ball.
I consistently hit the ball in the center of the club face about 90% of the time and have been told that I need to impact the ball above the equator on the club face in order to achieve more distance. When impacting below or at the equator of the club face, I am now putting a opposite gearing effect on the ball, thus making it not go as far.
I have spent many hours at the range with impact tape on the club face, tried different tee heights and ball positions, but still impact in the center of the club face.
My question to you is: does that make any sense to you and is it correct? If the information I was given is correct, could you please give me some advice on how to achieve the high impact on the club face.
The best place to hit the ball is always on the sweet spot generally in the center of the club face because this is where you are going to get the maximum trampoline effect from the high COR which all drivers are now designed to have (for more information on COR click here).
If the distance you are getting with your drives is not to your liking then you must check to see if your launch conditions are optimum for your head speed. If not and you are launching the ball too low then the first thing to do is change the loft to launch the ball higher. This will increase spin, which you may not want to do but you have to compromise.
If you are close to the correct launch angle and the spin is a little too high, then move the impact point higher on the face which will decrease the ball speed a little but get closer to optimum launch conditions by decreasing the spin because of the vertical gear effect. Most of us find it hard enough to find the clubface, never mind a particular spot on the face.
This impact location technique is a tweaking or fine tuning process when everything else has been done and adjusted. The difference in distance may only be a few yards so dont expect a significant change.
Teeing the ball higher is a standard technique to change the impact location on the face. You must be adjusting your swing each time you tee the ball higher, which is natural but try to keep the same swing and pretend the ball is teed lower than it is. I dont know how else to help you with your sweet spot problem. Boy! The rest of us would love to have your problem. I hope I didnt miss the sweet spot on the answer.
I had a question about wedges. I carry the normal pitching wedge and a 60 deg. lob wedge. I changed to a 54 deg. sand wedge, in theory, to keep an equal distance between wedges. One of the guys I play a lot of golf with carries a 50 deg. wedge, for a gap wedge, and no lob. I thought that the pitching and 50 are too close in distance but he swears by it, and after hitting it a few times I got a little confused. I guess my question is what would be the best sequence of wedges to carry?
Since manufacturers started cheating on the unwritten standard of lofts for specific numbered irons about thirty five years ago, clubs have been gradually getting stronger. This was started for marketing purposes to show how much better one club was than its competitor because it hit the ball farther but nobody told us the loft was three or four degrees stronger.
This resulted in clubs becoming extinct like the story about how They all rolled over and one fell out and the little one said roll over and they all rolled over and again one fell out etc. This is exactly how, in order the 1-iron and then the 2-iron and soon maybe the 3-iron are on the extinct list. The club that didnt roll over was the Sand Wedge which stayed in place. The loft of the SW is and has always been (for 50 or more years) about 55 degrees. Todays PW which used to be 51 degrees is 46 degrees and I have seen some at 44 degrees.
This has created the gap between the PW and SW so I recommend you fill it up with a Gap wedge or two. I have a 52 and a 56 with 14 degrees of bounce which I use as my SW and back off the PW for those 90 to 100 yard shots. I also open my SW for those occasional flop shots from very soft fairways or rough. Opening a SW with 14 degrees of bounce on firm fairways or hard pan usually results in the ball landing close to the cart girl on the next tee. Not a way to score well.
I suggest that you realign and have about 4 degrees difference between your wedges; with the PW at 46, GW 50 , GW 54 and a SW 56 or 58 with 14 degrees of bounce. The GW54 should have only 6 to 8 degrees of bounce so you may be able to use it for the flop shot. The Lob wedge is an extra club which requires you drop a club somewhere else.
Hope this fills the gap.
Frank Thomas, inventor of the graphite shaft, is founder of Frankly Golf, a company dedicated to Helping Golfers. Frank is Chief Technical Advisor to The Golf Channel and Golf Digest. 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 firstname.lastname@example.org