Swing Speed x Smash factor = Ball Speed

[timchump]

Is the above formula correct for example a 100 mph swing speed with a maximum smash factor of 1.5 equals a ball speed of 150 mph.

The reason i ask is i bought a swing speed gadget about a month ago

http://www.youtube.com/watch?v=rWk_0BJHpBQ

When i do practice swings without a ball, with a driver, i'm averaging about 90 mph occasionally get it into the mid 90's

but as soon as i start hitting a golf ball my average goes up to around 105 mph and i occasionally get it above 110 mph.


I thought the device maybe measuring the ball speed when i start hitting balls.

So my question is following the above equation is the ball speed measured as soon as it leaves the club face?

For example, when the ball is 1mm away from the face it is travelling at 150 mph?
(if this is the case the device surley can't be measuring the ball speed)

or does the ball accelerate to 150 mph? at some point later in its flight
(in which case the device might be measuring ball speed)

physics was never ,my strong point but i don't think it is the second option

I just can't understand why my practice swing speeds are so different to my actuals?

 

[Ethan]

It might be more properly said that smash factor = ball speed/swing speed, since smash factor is a measure derived from two observed measures.

Both speeds are based on the speed when the club or ball pass the measuring instrument, which is positioned to capture that very close to the point of impact/ball teeing position, often within a foot or so. But the ball loses speed quickly thereafter, so by the time it hits the ground it is closer to 50mph.

On your query about why the practice swings and actual swings differ, the obvious answer is that the swings are different. A device measuring your clubhead speed doesn't know or care if there is a ball in the way, so the difference must simply be that you swing harder at the actual ball.

A more interesting experiment would be to find out how well you maintain a high smash factor as you swing harder. You might find that as you swing harder, you lose smash factor and still only get the same ball speed. In which case you are better off swinging easier.

 

[timchump]

Thanks Ethan

So the formula is correct albiet rearranged.

And the device is measuring my swing speed when it increases with my "actual" swing, thats good to know.

Yes the swings are obviously different then.

Given my objective, with either swing is to get a high reading the difference is quite big imho

I would do the experiment you suggested but unfortunately i only have a £70 swing radar not a £35k trackman at my disposal

i think my actual swing in the main i have good strikes as i don't get wild left or right movements in the air, if i get a freak high reading the ball does tend to accelerate higher to an apex and drop, an average reading looks more like a rainbow flight

I guess i could measure the distance of my shots but i think there are too many other variables in this, - difficult for me to do accurately

Perhaps I'll to post up vids of my practice and actual swings hopefully to get peoples views on why the difference is soo much.....

 

[Ethan]

Thanks Ethan

So the formula is correct albiet rearranged.

And the device is measuring my swing speed when it increases with my "actual" swing, thats good to know.

Yes the swings are obviously different then.

Given my objective, with either swing is to get a high reading the difference is quite big imho

I would do the experiment you suggested but unfortunately i only have a £70 swing radar not a £35k trackman at my disposal

i think my actual swing in the main i have good strikes as i don't get wild left or right movements in the air, if i get a freak high reading the ball does tend to accelerate higher to an apex and drop, an average reading looks more like a rainbow flight

I guess i could measure the distance of my shots but i think there are too many other variables in this i think, - difficult for me to do accurately

Perhaps I'll to post up vids of my to different swings get peoples views on why the difference is soo much.....

If you can measure ball speed and swing speed, you can check if adding swing speed also adds ball speed, ideally 1.5mph ball speed per 1mph swing speed.

 

[timchump]

i can't... at the same time on the same swing which is the point right?

unless i can find a way for my device to measure ball speed

then i would have to buy another one, maybe worth it?

i would have to calibrate them, or check they are giving the same readings at least


i think next time im down the range i'll see if i can set it up to measure ball speed, then i might buy another and have my own budget trackman set up, well for speeds and smash factor

could be fun lol

 

[MashieNiblick]

I have an interesting book from 1995 called "Golf the Scientific Way" which has a lot of articles about various aspects of the golf swing and equipment. It has an article about the relationship between practice swings and real swings based on an analysis of 40 amateur golfers' swings. One of the findings was that for most of these players, when swinging without a ball, their swing speed relaxed by about 10%.

Another interesting finding was that most players didn't square the club face as much when making practice swings.

This was all with the technology of the time, using speed sensors and a special club. Don't know if there are more recent studies on this using more modern technology.

Nice to get it out again and see the adverts for Tommy Armour Silver Scot 855's, Rextar Balls and Ben Hogan Edge irons.

 

[timchump]

I have an interesting book from 1995 called "Golf the Scientific Way" which has a lot of articles about various aspects of the golf swing and equipment. It has an article about the relationship between practice swings and real swings based on an analysis of 40 amateur golfers' swings. One of the findings was that for most of these players, when swinging without a ball, their swing speed relaxed by about 10%.

Another interesting finding was that most players didn't square the club face as much when making practice swings.

This was all with the technology of the time, using speed sensors and a special club. Don't know if there are more recent studies on this using more modern technology.

Nice to get it out again and see the adverts for Tommy Armour Silver Scot 855's, Rextar Balls and Ben Hogan Edge irons.

that is interesting, backs up what i'm experiencing



i think perhaps focusing on the ball to hit, concentrates achieving a high speed in the right part in the swing, instead of aimlessly swinging the club on the practice swing

thanks for the reply,

im going to see of if i can find anything else on the internet about this phenomenon

 

[Region3]

I briefly had access to a device that measured my swing speed, and had the idea that I could guesstimate ball distances for easy, normal and flat out swings if I measured the club speeds for each of them without a ball.

I thought I was swinging as if a ball were there, but when I got to measure my ss with a ball in the way, it was the same as the flat-out-can't-possibly-swing-any-harder swing without a ball.

I would argue until I'm blue in the face that my practice swing was the same as my real swing UNTIL I proved it myself that it wasn't.

Very weird.

 

[timchump]

thanks gary

that pretty much sums what im experiencing, on my practice swing to get a high reading i literally throw my lower half at the ball, as hard as i can, what i "think" is a powerful swing, -if i'm lucky i get a reading in the mid 90's

as soon as i hit a ball it is consitently around 100- 105, and if i go for one i can just get it above 110

it's bizaire