Bubba
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mgranato
New
The calculation is achieved by taking ball speed & dividing it by clubhead speed - and the numbers shake out. Maybe 1.5 max is an urban legend
You guys are forgetting a big part of the equation with smash factors well above 1.50.
At the Atlanta tour stop, we saw one lessonee routinely put up 1.56 - 1.58 smashes.willgolfer
New
which part?
willgolfer
New
Re:?
FROM A TRACKMAN EMPLOYEE (allegedly)
I just wanted to add our comments to this debate going on about Trackman and Smash Factors. First of all, both the ball speed and the club speed in all versions of TrackMan software are measured. However, in version 2.1 and earlier versions, we sometimes measured the club head speed closer to the heel resulting in a lower club head speed by up to 5-6 mph. This has a dramatic influence on the smash factor:
Let us assume the correct club head speed is 100 mph and ball speed is 148 mph (S.F. 1.48). If the club head speed is recorded erroneously as 94 mph this would produces a smash factor of 1.57! In order to prevent this phenomenon which almost solely happened on drivers, we have in version 3.0 and 3.1 a mechanism gets rid of club head speed readings that have too high smash factors. In version 3.0 this “soft limit” is 1.48 where it is 1.50 for version 3.1. The absolute upper limit for smash factor is 1+COR, but this would require a very heavy club head (there exist no upper limit) compared to the ball weight (there exist no lower limit) and the impact should be a centre impact that puts no spin on the ball. For realistic club head weight of 215 g and a ball weight of 45.9 g for a low spin rate of 2000 rpm the upper limit for the smash factor will theoretically be (1+COR)*0.805, which for COR of 0.83 gives 1.474.
So when I say a “legal” driver and ball can not exceed 1.50 this is not 100% true, but for all the drivers and balls I know about it will practically be impossible to exceed 1.50 for smash factor.
Remember also in all this that the accuracy of the club head speed when using a TrackMan is +-1 mph. At 100 mph club head speed this could make a smash factor appear as anything between 1.465 to 1.495. Smash factor is a very sensitive ratio.
Furthermore, recall that the club head speed measured by the TrackMan is referred to the centre of the club face, which is not necessarily where the ball is impacted. If you move 10 mm towards the toe the club head speed will typically be 1.4% higher. This can also skew the smash factor a small amount.
In our next newsletter (approximately 2 months from now) we will be discussing the smash factor in more details, since this has really made people talk. If you wish to receive this newsletter, please go to our website to sign up for it.
I just wanted to add our comments to this debate going on about Trackman and Smash Factors. First of all, both the ball speed and the club speed in all versions of TrackMan software are measured. However, in version 2.1 and earlier versions, we sometimes measured the club head speed closer to the heel resulting in a lower club head speed by up to 5-6 mph. This has a dramatic influence on the smash factor:
Let us assume the correct club head speed is 100 mph and ball speed is 148 mph (S.F. 1.48). If the club head speed is recorded erroneously as 94 mph this would produces a smash factor of 1.57! In order to prevent this phenomenon which almost solely happened on drivers, we have in version 3.0 and 3.1 a mechanism gets rid of club head speed readings that have too high smash factors. In version 3.0 this “soft limit” is 1.48 where it is 1.50 for version 3.1. The absolute upper limit for smash factor is 1+COR, but this would require a very heavy club head (there exist no upper limit) compared to the ball weight (there exist no lower limit) and the impact should be a centre impact that puts no spin on the ball. For realistic club head weight of 215 g and a ball weight of 45.9 g for a low spin rate of 2000 rpm the upper limit for the smash factor will theoretically be (1+COR)*0.805, which for COR of 0.83 gives 1.474.
So when I say a “legal” driver and ball can not exceed 1.50 this is not 100% true, but for all the drivers and balls I know about it will practically be impossible to exceed 1.50 for smash factor.
Remember also in all this that the accuracy of the club head speed when using a TrackMan is +-1 mph. At 100 mph club head speed this could make a smash factor appear as anything between 1.465 to 1.495. Smash factor is a very sensitive ratio.
Furthermore, recall that the club head speed measured by the TrackMan is referred to the centre of the club face, which is not necessarily where the ball is impacted. If you move 10 mm towards the toe the club head speed will typically be 1.4% higher. This can also skew the smash factor a small amount.
In our next newsletter (approximately 2 months from now) we will be discussing the smash factor in more details, since this has really made people talk. If you wish to receive this newsletter, please go to our website to sign up for it.
I guess Trackman isn't always 100% correct. Check out Furyk's "highest" smash factor for the year:
Yes,
OR
someone inputed the wrong value on the form
faux_maestro
New
That response you posted from the Trackman employee implies that the numbers doesn't contradict the science/theoretical max. smash factor. It implies that there are errors in calculations. There is a big difference.
Brian Manzella
Administrator
I've seen DEAD CENTER HITS up around 1.58. HOT HEAD you see....
No.
No.
That's why there is a COR Limit. But they test .001% of drivers.
Probably.
You are a barrel of monkeys.
Steve Greffen
New
The radar systems do track the sweetspot of the club for club head speed, so if a player were to strike a ball near the toe the club head speed would measure slower than it actually was (the toe travels faster than the center and heel of the club). The real club head speed would be faster resulting in a faster ball speed making the smash factor higher for this situation. Made sense to me along with many others that heard it.
Yes faux, nice deductions. BUT, there is no theoretical max theoretically (changing the equipment, even marginally, changes everything) and there is no absolute measurement. So, at the end of the day, it's all an approximation, and inexact science. But a very useful inexact science.
mgranato
New
Cheating? Not at all! Our responsibility as a conforming player is to buy a driver on the conforming list. Period. It is not to by a driver on the conforming list then send it to the USGA to have it's COR tested.
Steve Greffen
New
...or if the club head speed you use for measuring the smash factor is less than what you actually deliver to the ball. Measure the middle but actual from the toe. Measuring 112 mph from the middle, actual delivered from the toe 115. Use the middle to calculate your smash factor and you start exceeding the threshold of 1.5.
There are unscrupulous people around who buy a driver from the conforming list and then "shave " the face thinner for a higher COR.The only way you can tell it's illegal is by testing it.
Don't quite understand the logic here.Trackman is setup to monitor the sweetspot or the middle of the club.It doesn't monitor the part of the clubface where the ball contacts.
Let's say the ball contacts the extreme toe of the club.The clubhead speed at that point may be faster(but I doubt 3 mph faster),however you won't be getting the same COR so ball speed won't be the same as if you hit the middle,so you really should not get a higher smash factor reading.
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