The rule
A new ball dropped onto a hard floor from 2.54 m must bounce between 135 and 145 cm. That is the test drawn above, with the lines where the rules put them.
Nº 15 The shelf
Ball tube
A padel ball is pressurised, and from the moment the tube is opened it starts to lose that pressure. The rules say how high a new one must bounce. Drop one and see.
The drop test
Drop it from 2.54 m.
Dropped from254 cm
Bounce0 cm
A new ball must bounce135 to 145 cm
Drag the ball up and let go · or press the space bar to drop it from 2.54 m
Pressure
Inside the felt is a rubber core held above the pressure of the air around it. Opening the tube starts a slow leak that no ball escapes, and the bounce falls with it.
Up high
Thinner air outside the ball lets the same pressure push it higher, so above 1,000 m the rules allow a ball that bounces between 121.92 and 135 cm.