Smash Factor and Spin Loft

Smash factor – The ratio between the ball speed and the club speed.

As a parameter, it is an expression of the player’s ability to generate ball speed based on a given club speed. Technically, the smash factor says a lot about the centeredness of impact and the solidity of the shot - there is a strong correlation between the degree of centeredness at impact and the obtained smash factor.

Here’s an example. If the player swings his club at 100mph and the ball speed is 140mph then his smash factor will be 1.40But if the golfer could obtain a smash factor of 1.48 with a more controlled swing having a lower club speed of 98 mph, the ball speed would be increased to 145 mph – i.e. an additional 5 mph ball speed by swinging slower. Since 1 more mph ball speed (all other things equal) will generate 2 more yards carry, an extra 10 yards is added to the drive in this case by swinging with more control! Further, the more controlled swing will most likely have a very positive effect on dispersion.

Hitting the ball well will improve your ball speed /smash factor this is where most amateur golfers go wrong by trying to hit the ball hard they loose control and make more off centre hits. From a coaches perspective it would be easy to help the pupil improve their ball striking rather than increase their club head speed.

So what is the highest smash factor you can achieve?? Well there are other factors that will influence smash factor. One is coefficient of restitution between club and ball (COR) and the other is Spin Loft. But tour players try and head for around 1.47

This then tells us that if you were to swing a heavy club at the same speed as a lighter club the ball will go further. Usually though a heavy club is swing slower and there may be a loss of control. It’s worth having a play with one club to experiment how this effect you as an individual. Everyone has a different strength.

The USGA and R&A set a limit for the coefficient of Resistance (COR) to 0.83.

Spin Loft – The angle between the club face orientation (actual loft) and the club head direction. (Attack angle)

SPIN LOFT = Dynamic (”delivered”) Loft —(minus) Attack Angle

We have a driver with 10° of loft.

If we have a level strike, with a delivered loft of 10° (no forward or backward lean), the spin loft will be 10°.

If we have a forward leaning shaft of 2°, and a delivered loft of 8° (because in this example, we are delofting the 10° head), and a downward strike of 2°, we have the same damn spin loft of 10°.
If we can accomplish a forward lean of 2°, and a upward strike of 1°, and a delivered loft of 8°, we get a SPIN LOFT of 7° and more ball speed, thus a higher smash factor.

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