Question:
Dave, Could u go into the square grove vs v groove thing again? 
Why the smiley?
You know very well why.. Cuz, when we were at Golfworks our tour guide looked at you like you were a sheep with anthrax when you asked about which cast clubs had square grooves.. Didn’t he say all but the ones specifically described to be made with v grooves, which until this year were about 2? I must admit I tried to help by saying – "are "U" grooves and square grooves the same thing?" – to which he replied – "yeah" then furrowed his brow like I was some kind of an idiot.. I must admit, it was one of the great moments of my life.. Thanks, Rick Do you agree with the calculations for the given offsets? I think I have proved to myself that the physics of the body with the proper swing create even more offset than I had previously thought. — —
Response:
Dave, Could u go into the square grove vs v groove thing again?
Why the smiley? I just asked that you do your homework and be specific. Come back with facts (like WHICH OEMs, other than Ping, have square grooves) and I’m sure we can have a perfectly reasonable discourse. But, here is some- thing I’m working on now..
— snip — (Actually, I knew Rick was working on that, and he knew I knew it. Last Friday at Dynacraft, he had a chance to try it out on Jeff Summitt, while I and a number of other RSGers watched and listened.) I’ll preserve as much of Rick’s original post as my news software will allow, at the end of my post. Summarizing what he says: - The clubface turns over when the forearms/wrists turn the club over at the bottom of the swing. - If you assume: (1) the clubface rotates about the shaft axis, and (2) it rotates 90 degrees in 1/100 to 1/200 second, that generates a significant additional velocity of the clubface as it strikes the ball (up to as much as 20 mph, depending on the numbers you assume). PRO: - It does explain your Ping experience. - One of the bigger hitters I know believes part of his distance is due to "wrist turnover". CON: - I can’t believe this happens in 1/200 second. I’m still having trouble at 1/100 second. Where did you get these numbers? I’m willing to listen to reasonable data. - Due to the bowing of the shaft to a toe-down position (and also to inertial effects), the axis of rotation AT THE GRIP (where wrist turnover is actually happening) is not pointing at the hosel, but much closer to the center of the clubface. So I tend to believe that the rotation is more nearly about the CG of the clubhead than the hosel axis. This would greatly reduce the effect you cite. I believe the second point was also made by Jeff Summitt, in different words. (Wasn’t that when you started describing an experiment using a pre-curved shaft? Or was that something else?) Anyway, my mind is open on this, but the burden of proof is clearly on the theory and not its converse. Cheers! Dave – Hide quoted text — Show quoted text -Just made an overlenth (1.5") 1 iron Ping Zing 2 copy with TT graphite s300 Gold shaft. Given that it was a cast Ping – I’d have promised decreased distance with less spraying of shots. But no! Once I learned how to swing it, it was straight as an arrow and 15 yards longer than my Apex Grind 1 iron (.5" overlength). .5" overlength is an advantage, but if you look at the PZ head design you see that the sweet spot is at least 3/8 inch further away from the shaft than the ground blades. The hosel is long gooseneck going far from the shaft before the clubhead expands from it. This leads to an added clubhead speed caused by the increased distance the sweet spot travels around the shaft axis during the forearm turnover part of the swing. Here are my computations on the forearm turnover effect.. my Apex Grind 1 iron has its sweet spot 5/8" out from the shaft.. the PZ has its sweet spot 1" out from the shaft.. (Please look at a Ping Zing and see how the hosel turns and stretches all parts of the clubhead away from the shaft axis very quickly.) Turnover of the (not wrist) forearm: (Check it out, it is the region between your elbow and wrist that turns 90 degrees, along with maybe 15 degrees from your shoulder (but this isn’t a kewl swing thing) that allow "wrist" turnover.) Anyway way, this turnover is hopefully the very last part of the swing, very relaxed and using the golfers body parameters for its consistency. It’s snappy and lasts only about 1/100 to 1/200 of a second for most golfers with reasonably good to professional quality swings. To get the sweet spot out that 3/8" further it takes a lot of added weight out there on the end of the clubface. This added mass leads to a slower turnover for people of normal forarm width and strength. For people like John Daly – a maximal "sweet spot speed" might be accomplished with an even more stretched clubhead with a sweetspot even 2" outside the centerline of the shaft. Stocky wrists and Popeye-like forarms are required to swing a club like this day in and day out. Here is another key – given that the arm/shaft angle isn’t 180 degrees – *ouch* – you have even more leverage and turnover speed than you might suppose. Here again, stonger-wristed folks have an advantage. So we have a turnover of 90 degrees in about 1/100 sec.. The radius of rotation is between 1" and 2" or up to 4" given the "strong wrist", "heavy arm" scenario. At a 1" distance of the sweet spot from the shaft axis, the normal swing with the shaft straight-out parallel to the forearm, and the reasonable 1/100 sec 90 degree rotation at the bottom of the swing, we get.. (most conservative numbers): 90 degrees is 1/4 of the circumference of circle.. total circumference is 2 * pi * r, r = 1" so you get 6.3", divide this by 4 since turnover is only 1/4 of a circle and the answer is 1.55 inch or so. 1.5 inches in 1/100 of a second is the same as a travel speed of 150 inches in one second. 150 inches per sec * 60 sec/min is 9000 inches per min.. 9000 inches divided by 12 inches per foot is 750 feet per minute. 750 feet per minute * 60 min per hour is 45,000 feet per hour. 45,000 feet per hour divided by ~5000 feet per mile gives 9 miles per hour. This is more than 10% of a normal golfer’s swing speed and the numbers used were very conservative. I’d say pros might get 30 mph of their swing speed from the forearm turnover / sweetspot offset from the shaft- axis effect.
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Response:
<stuff snipped : : Ok, here goes. It’s simple. I promise! : : I think we can agree that on a full shot, the point of a swing is to deliver : the clubhead to the ball at maximum speed. That means zero : acceleration. Think about that. Speed does not equal acceleration. At : top speed, you’ve stopped accelerating, right? <end of stuff snipped Mark, I enjoyed your post. Understood most of it As a certifiable hacker, I must admit that I, like many others (who may or may not admit it) keep seeking that ‘perfect’ driver (or the club or your choice) that will transform my game from a 24.7 handicap index to a single digit! Alas, it isn’t there. Oops! For those who still believe that, I apologize, and I apologize also to those manufacturers/vendors who often help us believe otherwise. At any rate, when I took the game up again this past summer I started spraying my tee shots just like in the good old days. After a couple of lessons, the slice disappeared (some of the shots still go to the right, but now for different reasons – ain’t golf great!) and a nice draw off the tee ensued. Great! Now that I felt I had the cure for my tee shot, I was well on the way to an average of 250 yards off the tee. (To me, the 250 yard tee shot seemed to be the great panacea of golf – 150 yards to the green permits lofted irons to the green instead of long irons or woods.) So the next time I visited Play It Again Sports, I saw one of those Big Brother (a Big Bertha knockoff) drivers. I bought he steel shafted version with a 10.5 degreee loft for about $70. During my next trip to my teaching pro, I pulled out my ‘panacea’ Big Brother club. The teaching pro frowned and said, "This is stiff. You can’t hit this club." After much discussion (and dismay on my part) the lesson continued and the result was the pro’s suggestion that I tee off with the 3-wood and keep the ball in the fairway. A couple of weeks later (while still in pursuit of the perfect driver!) I found an old Head ladies driver, discounted (for the third or fourth time) to $30. When I found out it was a ladies’ driver, I was a little disappointed, but not for long. I bought and proceeded to hit the best, straightest drives I’ve hit in many years (maybe ever?). Convinced that the more flexible shaft was the answer (Harvey Pennick didn’t hurt the issue any either), I had the Big Brother driver reshafted with a ’senior’ shaft. Dyn-o-mite! I’m 52 years old, apparently don’t swing the club all that fast, and my ego is significantly less than years ago (despite what my wife sometimes says). This has been a great experience. Now, when I’m convinced my chipping isn’t killing my game (basically it’s the short game that’s killing my game) I don’t believe I’ll hesitate to fork out significant dollars to have shafts for an entire set of clubs custom-made for me. While swing weights, club-head speed, shaft flexibility, and other parameters may be argued until the cows come home, my personal experience bespoke volumes about the "friendly shaft" aid to my own game. Art Burke Lenexa, KS PS Sorry for the long post.
Response:
Great Post Mark. I don’t mean to nitpick and seem like I’m restating the obvious, but the other critical success factor in the golf swing is to deliver the clubhead to the ball at maximum velocity SQUARE to the target line. (excepting deliberate fades, draws etc…). Thanks again for a great post. Bill Huang
Response:
Do Golf Shafts really affect your golf game that much? I have graphite 100 mph shafts, but my swing speed is about 88, but I hit most of my iron shots straight as hell. I am going to be purchasing Taylor Made Irons(Bubble)-and I was told to get stiff 90’s. Advice please russell
Yes they do. Their all different. You shoud hit them before blowing away the $$$.
Response:
Please excuse my subject line. It’s in jest, like the famous series. Do Golf Shafts really affect your golf game that much? …
((Much deleted to save time and space)) May the merry-go-round force be with you in your search. Let the flames and nit picking begin. :-) Regards, Mark
As an absolute beginner club maker and a pretty near invisible lurker on rsg for the last year or so, I say to Mark Thank You, Thank You, Thank You. Now all I have to do is figure out how to determine which shaft really works. Sometimes I think there are just too many goodies available in the Candy Store. Discrimination in choice is truly a learned art. To all of you, keep the good info flowing and I will, for the most part, just try to absorb it. Thanks Casey Jones
Response:
Now all I have to do is figure out how to determine which shaft really works. Sometimes I think there are just too many goodies available in the Candy Store.
I’ve been dismayed recently with the number of parameters that the manufacturers have been playing with. Too much to keep track of. I’ve had a strong suspicion that most of these are "product differentiators" that make little or no real difference. I had a chance to sit down and talk with Jeff Summitt (co-author of "Modern Guide to Shaft Fitting", one of my favorite club design books) last Friday — thanks for arranging that, Thor. After our discussion, I’m willing to believe that at least some of the new stuff isn’t pure hype, though I still think that most is. When I’ve collected my thoughts from the weekend, I’ll post more. Cheers! Dave
Response:
Mark, may I exerpt (or maybe use whole) your essay in the next edition of the Club Design Notes — with attribution of course? Cheers! Dave
hummina hummina hummina.. Dave, Could u go into the square grove vs v groove thing again? But, here is some- thing I’m working on now.. Just made an overlenth (1.5") 1 iron Ping Zing 2 copy with TT graphite s300 Gold shaft. Given that it was a cast Ping – I’d have promised decreased distance with less spraying of shots. But no! Once I learned how to swing it, it was straight as an arrow and 15 yards longer than my Apex Grind 1 iron (.5" overlength). .5" overlength is an advantage, but if you look at the PZ head design you see that the sweet spot is at least 3/8 inch further away from the shaft than the ground blades. The hosel is long gooseneck going far from the shaft before the clubhead expands from it. This leads to an added clubhead speed caused by the increased distance the sweet spot travels around the shaft axis during the forearm turnover part of the swing. Here are my computations on the forearm turnover effect.. my Apex Grind 1 iron has its sweet spot 5/8" out from the shaft.. the PZ has its sweet spot 1" out from the shaft.. (Please look at a Ping Zing and see how the hosel turns and stretches all parts of the clubhead away from the shaft axis very quickly.) Turnover of the (not wrist) forearm: (Check it out, it is the region between your elbow and wrist that turns 90 degrees, along with maybe 15 degrees from your shoulder (but this isn’t a kewl swing thing) that allow "wrist" turnover.) Anyway way, this turnover is hopefully the very last part of the swing, very relaxed and using the golfers body parameters for its consistency. It’s snappy and lasts only about 1/100 to 1/200 of a second for most golfers with reasonably good to professional quality swings. To get the sweet spot out that 3/8" further it takes a lot of added weight out there on the end of the clubface. This added mass leads to a slower turnover for people of normal forarm width and strength. For people like John Daly – a maximal "sweet spot speed" might be accomplished with an even more stretched clubhead with a sweetspot even 2" outside the centerline of the shaft. Stocky wrists and Popeye-like forarms are required to swing a club like this day in and day out. Here is another key – given that the arm/shaft angle isn’t 180 degrees – *ouch* – you have even more leverage and turnover speed than you might suppose. Here again, stonger-wristed folks have an advantage. So we have a turnover of 90 degrees in about 1/100 sec.. The radius of rotation is between 1" and 2" or up to 4" given the "strong wrist", "heavy arm" scenario. At a 1" distance of the sweet spot from the shaft axis, the normal swing with the shaft straight-out parallel to the forearm, and the reasonable 1/100 sec 90 degree rotation at the bottom of the swing, we get.. (most conservative numbers): 90 degrees is 1/4 of the circumference of circle.. total circumference is 2 * pi * r, r = 1" so you get 6.3", divide this by 4 since turnover is only 1/4 of a circle and the answer is 1.55 inch or so. 1.5 inches in 1/100 of a second is the same as a travel speed of 150 inches in one second. 150 inches per sec * 60 sec/min is 9000 inches per min.. 9000 inches divided by 12 inches per foot is 750 feet per minute. 750 feet per minute * 60 min per hour is 45,000 feet per hour. 45,000 feet per hour divided by ~5000 feet per mile gives 9 miles per hour. This is more than 10% of a normal golfer’s swing speed and the numbers used were very conservative. I’d say pros might get 30 mph of their swing speed from the forearm turnover / sweetspot offset from the shaft- axis effect. (FTSSOFSAE) :) I guess what I am trying to say is that this where a lot of people lose swing speed by keeping their forearms stiff to try to ensure that their shot will go straight, and it is interesting that certain clubs in their design try to promote forearm turnover using offset hosels and outside weighting like the PZ. Clubs might be designed that allow incredible swing speeds based on this effect, but I would guess that the average wrist would not hold up under the strain of swinging such a club with any frequency. Still, it is a better solution than just making a club longer IMHO. Thanks, Rick — —
Response:
I’ve deleted Marks tome on why shaft characteristics are important, to save bandwidth. If you missed it, go back and read it, because…. That was GREAT! Right on the money. Not an untrue word there. (Well, I have a little problem with the paragraph on the "merry-go-round force", but it is a useful visualization tool.) Mark, may I exerpt (or maybe use whole) your essay in the next edition of the Club Design Notes — with attribution of course? Cheers! Dave
Response:
– Hide quoted text — Show quoted text – Please excuse my subject line. It’s in jest, like the famous series. Do Golf Shafts really affect your golf game that much? … Russell’s question nicely illustrates my belief that the vast majority of golfers don’t understand the relative importance of the shaft as a club component. I hope this post reaches some readers who ordinarily would roll their eyes at this type of discussion. I promise no techie stuff. I hope it provides thosse who aren’t given to considering customized equipment to pause and ask if they’ve done all they can do to ensure maximizing their investment in the game. Ok, here goes. It’s simple. I promise!
What an excellent post! These are things many of us know, intuitively, yet do not really pay attention to. Thanks, Mark. Bruce Bruce E. Newman | | Home: (506) 457-9800 Fredericton,NB,Canada | Dreams…screen | Office: (506) 462-6421
Response:
Please excuse my subject line. It’s in jest, like the famous series. Do Golf Shafts really affect your golf game that much? …
Russell’s question nicely illustrates my belief that the vast majority of golfers don’t understand the relative importance of the shaft as a club component. I hope this post reaches some readers who ordinarily would roll their eyes at this type of discussion. I promise no techie stuff. I hope it provides thosse who aren’t given to considering customized equipment to pause and ask if they’ve done all they can do to ensure maximizing their investment in the game. Ok, here goes. It’s simple. I promise! I think we can agree that on a full shot, the point of a swing is to deliver the clubhead to the ball at maximum speed. That means zero acceleration. Think about that. Speed does not equal acceleration. At top speed, you’ve stopped accelerating, right? At perfect impact, all the accelerating is done, kaput, finished. We can’t make it go any faster. A moment later it’s going to be slowing down. If we hit the ball while the clubhead is still accelerating, then we’ve wasted some energy. Our timing is off. The idea of ‘accelerating thru the ball’ is nonsense. That’s a [helpful] swing thought that hopefully prevents you from decelerating prior to impact, which is definitely NOT the goal. How do we accomplish this maximum velocity? With a combination of a few things: Every good swing will be moving the club laterally towards the target at impact. (Despite what you may have heard, the head and body do move away from the ball on the backswing, and towards it at impact). Don’t believe it? Taught that your head should stay still? Hogwash. Check out some of the awesome video sequences on the Golf Channel – they are begining to use some seriously helpful video technology that proves this, among many other things. You can’t seem to avoid slow motion Tigers on golf TV these days. Check him out at impact. He’s throwing himself at the ball (moving lateraly), yet keeps his balance. His swing is technicaly flawless. It’s a good one to emmulate. Every good swing will employ "the merry-go-round" force. I’ll let others scream at eachother about centripital and centrifugal forces. I promised I’d keep this simple. Just think of a yo-yo being swung around in a circle at the end of its string. It doesn’t take much effort to get that bugger going REALLY fast. Powerful force, this merry-go-round thing. Your torso is your finger, your arms and shaft are the string, and the clubhead is the yo-yo. Really. Turn that torso, baby. [Oh boy...I've unwittingly rekindled the epic "SHAFT IS LIKE STRING AT IMPACT" argument of 1995...arrgh] That’s the simple stuff that every good swing has. Here’s SOME of the stuff that every swing has, regardless of how good it is: EVERY SWING WILL: employ a certain rate of acceleration; have a certain duration; have its own mix of forces, in different amounts and ratios; "load" the shaft with energy at different times and in different amounts; "unload" the shaft of energy at different times and in different amounts; see the shaft propel the clubhead to a max speed at some point in time; see the golfer propel the clubhead to a max speed at some point in time; SO THE GOAL BECOMES… The goal is to have maximum shaft-induced clubhead speed at the same time as you’ve attained maximum golfer-induced clubhead speed. Read that again and think about it. It’s about harmonizing with your shaft. Synchronize these points at ball impact, and you’ve given that ball a serious "treatment". Ever wonder why some "effortless" swings result in awesome ball flights? Harmony. Tempo. Maximizing the shaft’s contribution to the swing. "Getting out of your own way". This is why club fitting is a black art, and why there are so many different theories, and why most are resigned to ignore the problem and why some are so obsessed with solving it. And why the vast majority of golfers play with clubs that don’t work for them. It’s not the head that matters, it’s the shaft. Sure, the clubhead’s loft and lie need to be calibrated as well, and matched to the shaft, but the overwhelming critical success factor of a full swing is the shaft. Different shafts will respond to different swings in different ways. The goal is tune your swing to the best of your ability, and then tune your shaft to your swing. I understand that this is a huge over-simplification of the golf swing and our goal. However, I really believe that what I’ve written here drills to the essence of maximizing the performance of our full shots. There is no universal solution to shaft fitting. Some of those offered are madeningly complex. Go boldly into that dark night. There is a solution for you, because your swing is uniquely yours and frighteningly repetitive regardless of what you may think. The path you must take to find YOUR solution is challenging. The rewards are HUGE. May the merry-go-round force be with you in your search. Let the flames and nit picking begin. :-) Regards, Mark
Response:
Do Golf Shafts really affect your golf game that much? I have graphite 100 mph shafts, but my swing speed is about 88, but I hit most of my iron shots straight as hell. I am going to be purchasing Taylor Made Irons(Bubble)-and I was told to get stiff 90’s. Advice please russell