travlerajm
Talk Tennis Guru
Snapback is actually a misnomer.
In the 5ms that the ball is in contact with the string surface, it compresses and then decompresses.
In the case of a topspin groundstroke, the ball pulls downward on the mainstrings as it compresses.
Then as it decompresses, it starts to pull upward on the mains as the ball’s surface starts to move upward faster than the stringbed due to its rotational moment of inertia. If the main strings are locked, then they are not free to travel upward with the ball’s surface, so they will exert a downward frictional force on the ball. This downward frictional force limits topspin.
But if the mains are not locked, the downward frictional force acts for a much shorter period. This allows the ball’s surface to continue to accelerate longer, generating more ‘overspin’ before it leaves the stringbed, resulting in much higher rpm.
So strings that can ‘snap back’ do generate more topspin, but it has nothing to do with how fast the mains snap back when you pull down in them with your fingers.
In the 5ms that the ball is in contact with the string surface, it compresses and then decompresses.
In the case of a topspin groundstroke, the ball pulls downward on the mainstrings as it compresses.
Then as it decompresses, it starts to pull upward on the mains as the ball’s surface starts to move upward faster than the stringbed due to its rotational moment of inertia. If the main strings are locked, then they are not free to travel upward with the ball’s surface, so they will exert a downward frictional force on the ball. This downward frictional force limits topspin.
But if the mains are not locked, the downward frictional force acts for a much shorter period. This allows the ball’s surface to continue to accelerate longer, generating more ‘overspin’ before it leaves the stringbed, resulting in much higher rpm.
So strings that can ‘snap back’ do generate more topspin, but it has nothing to do with how fast the mains snap back when you pull down in them with your fingers.