This week, a pasta inspired racket design….
On Saturday July 2nd at 2.59pm I was repeatedly refreshing my web browser trying to secure a Wimbledon Centre court ticket. My luck was in, that and being able to quickly pass the “I’m not a bot” ticketmaster test, meant I was the proud owner of a pair of tickets. What followed was a glorious Sunday of tennis and a train ride home leaning about racket design!
Most players favour a criss-cross design, with perpendicular strings (vertical and horizontal) woven together. However, in 1977 a new rage of “double strung” or “spaghetti” rackets caught on. These rackets had two sets of vertical strings tied together, so if one moved they all did. In between the vertical strings were only 5 horizontal strings which importantly were not woven into the vertical strands. In places where the horizontal and vertical strings lay on top of one another, plastic clips were inserted to enhance the amount the strings could slide. The result was a racket surface which could move a considerable distance.
When impacted with a ball, if one vertical string moved sideways then they all did. As the vertical strings sprung back, because the movement was tangential to the direction of the incoming ball, the strings not only pushed the ball back away from the racket but also gave it considerable spin. Players started to notice the success of the modified spaghetti rackets and began to swap over. In the US Open, the little known Mike Fishbach converted his own racket to be “spaghetti style” by using blind cord – and went on to win his match (tennis.com).
However, the pasta inspired racket was to be short lived, by 1978 the double strung racket design was banned. Interestingly, whilst today’s players must have rackets with interwoven strings, the strings are made of polyester which naturally moves and bounces back, allowing similar levels of spin. If not controlled the spin can lead to the ball exiting the racket at a higher angle, travelling higher over the net and out the back of the court (physics.usyd.edu.au).
At the back of a cupboard I do have a tennis racket. Whilst I’ve always enjoyed a game I never been any good; maybe it’s now time to take the blinds down and try some DIY modifications? On the other hand, perhaps I should just enjoy the second week of Wimbledon with some strawberries and cream. Yep, the seconds one wins, Game, Set and Match!
For a more detailed look at the physics of tennis balls and strings check out the paper by R. Cross, Impact of a ball on a surface with tangential compliance, Am. J. Phys. 78, 716-720 (2010).