Why size matters as it pertains to distance

[clevited]

I ran calcs again rq. My driver is 335g, 44.5 inches from butt end of grip to middle of face (1.1303m), 120 mph (53.6448 m/s) with .7 for static coeff of friction. I got 137 lbs force each hand. With coeff of friction at .5, which it very well could be, hard to say, I got 191 lbs force per hand. Hopefully I did that right. Its a simple formula but I could be overlooking something.

[Fade]

I think your numbers are on the high side, if you assumed the entire driver weight to be concentrated at the head, and if you assumed that the length measurement from your driver represents the radius of motion.

[clevited]

Correct, I am making an assumption about where the club pivots, the coefficient of static friction between hands and club, and simplifying things with an easily known length. Feel free to run it with some more detailed assumptions. I would be interested to see your results. I might measure my club up later and see what I end up with.

[Pepperturbo]

All depends on where your strength comes from. I am 70, 5'10 - 218lbs of muscle. Last year I was down to 200 and lost some distance. Now that I am back to what's been my normal weight since football days, I am hitting the ball further, 10-20yds further. Little guys like Rory hit the ball a long ways when young because they have speed and quick twitch muscles. As they age, distance will shorten and muscles will slow and NO real muscle strength to back it up.
Depending on age and body composition, size matters. I don't have to swing the club as fast as forty years back, just have the strength to hit the ball hard. At 70 I still have muscle strength that others even in their fifties are loosing or have lost. Working out since youth at the gym is also why I am still effective with long irons.
PS, @chipa mentions TW regret adding weight. What he doesn't mention is that added weight was put on a body structure that wasn't built to hold it, so complications result. I am built similarly to Brooks Koepka only a bit more muscle, larger bones but flexible.

[Fade]

Just for contrast, I will throw something out at the low end, with round numbers: 200 g mass, 100 mph speed, 50" radius: 71 'pounds' total (or per hand if a CoF of 0.5 is used).

[clevited]

Found some numbers I had in a spread sheet for one of my older drivers. I kept the assumption of location of pivot point, and used the R at the club's balance point instead of end of head. Club weighed a little less too. Due to velocity being squared, the hand force needed came down quite a bit. So if we can test the typical coeff of friction for a hand/glove/golf grip, and or the best case coeff and worst case coeff, we could get an idea of how important grip might be for a given swing speed.

 

Edit: Keep in mind, I am not trying to calculate any torque of the grip in the hands from the club head rotating closed, nor the fact that the club is accelerating and decelerating creating forces, nor the effects of impact with the ball. This is just calculated as if the club is at a constant velocity. There are lots of little things that should ideally be accounted for. If a person has the time, they could really nerd this out and get as accurate as possible. I am not volunteering to do that at this time, just trying to create some discussion regarding this thread subject. If someone does have the time, I would certainly love to read about the assumptions made and results.

[SirFuego]

5 Techniques to Improve Grip StrengthBasically, it seems like it's not possible for you to have too much grip strength. The stronger your grip gets, the easier it will feel to hold onto the club. The actual amount of force needed to hold onto the club remains the same, but that might mean you now just need to grip it with a "3" out of 10 instead of a "6". This means that the tension in your swing should decrease as well. It of course benefits you even more hitting the ball from deep rough buried bunker shots.

[clevited]

Great points. I ran a little simulation with my numbers just to see what I would get and check my math. I used a driver I had some numbers for when I built it.

Weight 332 g

Length from butt end of grip to balance point 32 inches (.8128m)

Speed at balance point 87.27mph (39.01m/s)

Head speed 120 mph (at center of club face and measuring 44 inches from butt of club)

My simulation (using Solidworks Motion) matched almost exactly my hand calculations. I bascially just animated a simple pendulum going a constant velocity.

Results of hand calculations are below showing friction coeff of .3, .5, and .7. I am just making guesses here as to worst case scenario (playing with wet or really worn grip) ranging to best case scenario (brand new glove, brand new grip). If this ends up being an accurate estimation, it seems to show that grip strength could be a limiting factor for some and as SirFuego said, you can never have too much. Again, this is only taking into account centripetal force, there are torques and accelerations and impact vibrations in a real swing as well. There is also the taper of the grip I don't take into account. If anyone sees errors or find something different please point it out. Might start another thread if people find this subject interesting enough, but I think it might just be me that geeks out about it.

 

Edit: Just wanted to point out, only the table with .3 coefficient of friction produces grip strengths outside the range of just about every strongman that ever lived, the rest are very within the range of human capability.

 

[cxx]

I took a couple lessons when Golftec was new. They had that device that you strapped on with a large umbilical connecting to the computer and a ballistic camera. Early days. The one thing that they emphasized was hand strength limiting club head speed. Can't remember the numbers but I did get one of those hand exercise gizmos and used it in the car. Anyone remember what their rule of thumb was? I think I remember it conforming to the numbers in the .5 friction table above.

It would seem that the really tacky grips might have a better friction coefficient and require less grip strength.

 

[Yuck]

So fresh grips with twice the friction requires half the hand strength?

[Fade]

I don't know what a reasonable number is for the coefficient(s) of friction. Could it be higher than 1 for a good grip/hand or grip/glove combo? Also, with the skin being pushed into the pattern on - say - a Lamkin Crossline grip, there might be more to it than just friction.

[clevited]

Yeah, I don't know for sure. I simplified a potentially complicated thing to quantify. At the very least, it maybe shows some insight into the value of keeping grips clean and tacky as well as shows there could be value in increasing ones hand strength. This is something where testing a bunch of individuals and sorting their performance by hand strength could be very interesting.

[clevited]

Ok, found an unused grip and had a brand new golf glove to test with. I tilted a board with glove secured to it and grip resting on the glove. It started sliding at 39 degrees (averaged several tries) which translates to around .8 for coeff of static friction. Below is the new table. Based on this, it doesn't look like velocity alone would be enough to cause any average person to limit their speed because of grip strength until you get into the 130s maybe. It does show that if you let your grips get bad, or don't use a glove (grip slipped in my bare hand at around 35 degrees which equates to .7 coeff friction), you could be hurting yourself more than you think. I think I will try to simulate a swinging club more accurately (not with a constant velocity this time but a realistic acceleration rate) tonight or tomorrow to see if anything changes there.

 

[ThinkingPlus]

Rubber on rubber is 1.16. Leather on rubber will be a good bit less.

[clevited]

Ok, ran another simulation with a more realistic acceleration of the club. I still used the pendulum model rather than incorporate any rotation from forearms rolling over, I just don't think that is a huge deal. Anyway, got exact same result. So it looks like hand strength is important but having stronger than average hands isn't necessary to have well above average swing speed. This can vary a lot though depending on if you swing bare handed, use a new or old golf glove, have leather or plastic golf gloves, use leather or rubber grips, have sweat or water on grip etc. I think if we use that .8 for friction as ideal, and .5 perhaps as worst case, I think we kinda can see what can go on. One could even say, a friction coefficient closer to that .7 or .6 value could be a possible average for a typical used golf grip (edit: confirmed old grip and glove I would still consider good to use had friction value of .55). They do accumulate sweat and dirt and skin oils as well as have their textures rubbed smooth. It is hard to say but something to think about. Just for reference, according to topendsports.com (no idea if reputable) an average man's grip strength in his prime is right around 104 lbs, and an average woman's grip strength in her prime is around 74 lbs. A "strong" grip strength for men is 127 lbs, and a "strong" grip strength for a woman is 91 lbs. As was mentioned in an earlier post with a link, the more grip strength you have in surplus, the more in control of the club you might have. Hopefully I didn't bore too many with the geeking out. I had always wanted to look into this and I am rather satisfied now with the results. Wasn't what I had expected as I thought the required strength would be a bit higher but interesting none the less to me. Carry on.

Here are all of the tables in one spot for various friction values should anyone want them.

 

.3 value for friction is generally considered slippery, so this might show why you throw your club in the rain lol.

Then next two tables could represent a typical used grip and glove with friction values between .5 and .8. (edit: tested older grip and glove and got value of .55 so seems average friction might be much lower than the brand new ideal .8)

Friction value for brand new leather glove and brand new rubber grip (not corded or wrapped, just plain rubber with slight texture)

[McCoy135]

Size doesn't necessarily translate to length. I know a lot of big guys that can't hit it out of their shadow and some little guys that can absolutely smash it. We all do, I'm sure.

I think Bryson did what most people don't do, he sequenced his development. He was already flexible, he already had his mechanics optimized and he's was already very efficient in his swing. He then added a lot of strength while maintaining all of these other things. Everybody seems fixated on his 2 shirt size increase, but look at the difference in his lower body. His base is incredibly strong which allows him to generate a ton of rotational speed and still be able to maintain balance and control.

It's pretty amazing that he figured out how to do that and that he has the athletic ability execute it.

[smashdn]

You guys about to get lost deep, deep in the weeds.

[ThinkingPlus]

Fortunately we have a copy of the Principia to guide us through.

[SirFuego]

I might regret opening this potential can of worms, but wouldn't taper on the grip also make it easier to hold onto the club, thus requiring less grip strength? Does the fingers wrapping around the grip create some sort of "Chinese finger trap" effect (I'm sure there is a more formal term for this and I'm not even sure it's the right "concept", but that's as close as I can think of) where (effectively) the coefficient of friction is also increasing as the speed increases?

Also, I've seen videos of guys like Vijay Singh and Fred Couples whose right hand is basically off the grip at impact. Not to mention that most golfers only wear one glove. So the lead hand likely needs to work "harder" to hold onto the club than the trail hand, so I don't know that it makes sense to distribute the force equally across both hands from a simulation point of view. I'm not a mechanical engineer, but my day job is writing software simulations of real-world things, so I understand the need for certain simplifications (especially as a first cut), but I always need to question whether or not a model is too simple. "All models are wrong, but only some are useful."

 

[clevited]

You make a lot of good points and I mentioned some of these things in an earlier post. There are certainly more variables than I addressed. I made many assumptions to simplify things as much as possible but still attempt to obtain useful data. We don't really know if one hand has to work harder than the other although I would guess that the dominant hand tends to be the controller of the club for many. One hand is gloved and one is not so yeah, you lose something there. The grip size makes a difference depending on hand size. The type of grip you use, interlocked, over lap, baseball. The taper certainly plays a role but if you have ever swung a club in the rain, taper doesn't do nearly enough imo, slipping is slipping even if just a little. Lots of things can contribute to this but the data I tried to calculate was to get a general idea of "if" hand strength "could" play an important role regarding swing speed of an individual. From what I have found it seems it can but not quite as much as I was thinking. The only way to really test this is to get a bunch of volunteers and control for variables as much as possible and see if there is a direct correlation imo.

[SirFuego]

This was a comment made on another website that is forbidden to be mentioned here (google "SuperSpeed grip strength" and the article on a SuperSpeed case study should show up). If you dig into the comments section, there is a comment by a user named "SUPERSPEED GOLF" (of which is probably safe to assume is legit):It is very important when you gain speed quickly like you did in your case to also make sure that your body can support and stabilize this new speed. In your case, we would test your grip strength. Research shows that most tour players have significantly stronger grip force than most amateur players. This doesn’t mean that they grip harder, just that their potential for grip strength is greater. For example a tour player may average somewhere in the 55-60 PSI range when tested for max with a golf grip sized dynamometer. Most amateurs will test for a max around 30 PSI. We find tour players usually grip with about 50% of their max (this changes throughout different parts of the swing), so their effective grip strength is about 25-30 PSI. Most amateurs cannot maintain this as it is near their max potential.

It might give you something more to work with to see how realistic those forces are.

[clevited]

Interesting. I found what you were talking about. Just from some quick estimates, I am not sure how they got those pressure numbers. Relatively speaking however, I am sure they are accurate but from what I can calulate is the area of the grip the hands act on, that is some superman grip above and beyond most of the worlds strongest men. I could certainly be over estimating the effective surface area being gripped and or the maximum grip pressure that can be applied to a smaller diameter object compared to most dynamometers including the rather standardized grip trainers. Either way, what they are saying seems to give some credit to my initial suspicions and does reinforce the importance of hand strength in the golf swing. Thanks for posting that.

[clinkinfo]

It really is this simple guys. Your all making it way complicated. Sosa and McGuire did steroids to get bigger so they could rotate harder and the bat would go faster. If you get Schwarzenegger big, you can’t get into the correct positions anymore, so there’s a line you can’t cross. What that is for each person, is probably slightly different.

[clinkinfo]

Your Weight is not the same as strength. He would hit it further if he was STRONGER. His weight isn’t relevant except as a “measure” of strength when that weight is clearly muscle

[Jifmoli]

Correct, it doesn't. It would if the mass moves in the direction of travel. But his body isn't behind the direction of the club head, the club rotates around the body and pivots around the wrist. he just rotates faster now.

But his swing has changed as well: wider stance, comes in shallower and uses his legs much more (dipping). Personally I think it is great how he transformed and he must have bodybuilding genes to pack on that much muscle that fast, wow.

[BenSeattle]

I'm no physicist but to my way of thinking there are a number of factors that contribute to a long drive. In no particular order:

A solid hit

A technically sound golf swing (correct sequence: weight shift, turn, late hit, etc.)

A club that fits

Fast-twitch muscle fibers

Strength

Mass

Some of these ingredients can be worked on, such as technique and strength. Fast-twitch muscle fibers? Perhaps not so much. Still, speed isn't everything. It was written that a grain of sand traveling at the speed of sound wouldn't even knock a golf ball off a tee -- there's no mass behind the contact. Haven't we all seen, at least once, some big guy, a football player with minimal golf skills, take a swipe at a ball and just KILL THE THING? Lots of muscle, perhaps some speed and TONS of mass. Is Bryson generating more clubhead speed? Unquestionably, but as pointed out earlier, the dude is swinging out of his shoes.... BECAUSE TODAY HE CAN -- and without fear of injury. Now, you combine that with the added mass which 40 pounds provides and you're going to get a player who has increased his distance considerably. However, in my book this bulking up won't work for everyone and here's just one reason why: Dechambeau's golf swing. His swing is barely past three-quarters; if he tried to go past parallel his big upper body wouldn't get him get there. Therefore, the long, flexible swinger today who decides to Get Big, might just find himself restricted by a large chest, shoulders and arms. And will likely spell getting shorter....despite the additional mass. (But at least you'll look great at the beach!)

[indianagolf2]

Need all aspects of the game. Jordan spieth won because of his accuracy and putting. Short game and putting are critical if your not long.

[indianagolf2]

Ben jackson golf rhode island teaches clubhead speed. Hes mid 70s and swings 113mph..heck he might even be 78.

[chippa13]

Rory is tiny by comparison and crushes it. Good form trumps all.

[garyt]

Or the fact that the added strength allows him to swing that fast now and still keep it on the planet?