Gleicht Backspin Sidespin aus?

Kann Backspin Sidespin ausgleichen? Diese Behauptung wird immer wieder aufgestellt. Schon 1994 hat das Golfforum Alastair Cochran dazu befragt.

Can backspin counteract sidespin?

Q: What is the reason for the fact that a ball which was hit with a very lofted club doesn´t curve as much as a ball hit with a club that has very little loft? Is it the fact that a lot of backspinn really compensates the sidespinn, as it is usually explained, or is it the fact that a ball hasn´t got as much width the more you get to the bottom of it, so that the point of contact can´t be so far off center? Or is it a combination of both?

Alastair Cochran:

The answer to your question about lack of slice or hook curve an a very lofted club is quite complicated, which requires a three dimensional model (or matheniatics) to explain. Here is a very brief summary.

Basically the „usual“ explanation is close to being correct. The amount of pure sidespin – spin about a vertical axis – is much smaller for a 9iron swing that is, say, 3° off square, than for a driver or a 1 iron.

Let´s go back to basics: A shot with any club where the face is not square to the swing dlrectlon imparts spin, which can be regarded as having three components:

  1. Spin about a horizontal axis at right angles to the flight – we call it backspin

  2. spin about a vertical axis sidespin, and

  3. spin about a horizontal axis along the direction of play – I call this „rifling“ spin, like a rifie bullet.

A shot with any club where the face is square to the line of the swing imparts neither sidespin nor rifling spin – just backspin. With a driver this may be 3000 rpm, with a 9 iron 8000 rpm.

A shot wich a driver that is 3° non square (out to in perhaps) will impart 600 800 rpm (slicing) sidespin, and only 50–80 rpm rifling spin. A similar shot with a 9 iron would have perhaps 200 rpm sidespin and about the same amount (200 rpm) of rifling spin.

These are just informed guesscs an my part but they should not be far wrong.

Not only does a 9 iron shot have less sidespin than a drive hit with the same amount of club face error, but it also travels more slowly. The sideways force exerted by the air (because of the spin) increases as the speed of the ball increases – in fact it is approximately proportional to the square of the speed – if the speed doubles the force multiplies by four. A 9 iron shot sets off at less than 2/3 the speed of a drive, so the sideways force on it, for the same amount of sidespin would be less than half (2/3 squared = 4/9). Add this to the fact, as I have already said, that the sidespin on the 9 iron is less, then the sideways force on the sliced 9 iron is much less than on a drive.

Noch keine Kommentare

Kommentar verfassen