The sweet spot on your racquet's stringbed where impact with the ball does not produce uncomfortable vibrations is called the node of the first harmonic.
Difficulty: Easy
Time Required: 5 minutes
Here's How:
- Place an ordinary index card against either of the faces of your racquet handle that are parallel to the plane of your strings.
- Position the index card so that 2/3 of its length extends beyond the end of the racquet butt.
- Apply a piece of tape perpendicular to the boundary between the edge of the index card and the racquet handle, extending one inch onto each surface.
- Hold the racquet with the butt pointing straight up.
- Apply another piece of tape that starts on the (horizontal) butt cap and then makes a 90-degree turn upward and attaches to the lower middle of the index card. Leave a little slack.
- Hold the racquet loosely, butt end up, between your thumb and forefinger, 6 inches below the butt end.
- Bump the butt end of a second racquet against your stringbed, causing the first racquet to swing back and forth like a pendulum.
- Bump near the tip of your racquet and note that the index card buzzes loudly.
- Bump near the throat of your racquet and note that the index card buzzes, but less loudly than at the tip.
- Keep bumping the stringbed in different locations. Your harmonic sweet spot is the area of your stringbed in which bumping does not make the index card buzz.
Tips:
- If you can't produce a buzz anywhere, this does not, unfortunately, mean you have the world's biggest harmonic sweet spot. You probably taped the index card too tight.
- Hitting the harmonic sweet spot can greatly reduce arm fatigue and irritation.
- See the links below for how to find your other two sweet spots.
