Friday, June 19, 1998 Published at 16:23 GMT 17:23 UK
Racket science and the hard sell
The changing shape of the tennis racket, 1930 - 1998
It's that time of year when life imitates sport, when inspired Wimbledon watchers dust down their tennis gear, fight to book a court and try to reproduce that Agassi ace they just saw on TV.
For sales, technology is the key word.
Wilson, the world's largest racket manufacturer, is promoting its Hammer titanium-enhanced range this year. Slazenger are pushing their Phantom Tour Braided series featuring a "unique Optimum Mass System which increases mass at key points to give a higher percentage of controlled shots".
Palms, paddles and polymers
Tennis was not always so hi tech. The ancient Greeks and Romans used their bare hands to play the forerunner of tennis, hence the French name Jeu de Paume (Game of the Palm). Over 2,000 years, the racket evolved from a hand glove to a wooden paddle, or battoir , and finally into an oval frame strung with sheep gut.
Metal rackets were introduced in the 1970s. They were made of aluminium and fibreglass and the heads expanded to increase the sweet spot, the area at the centre of the racket where the frame is best balanced and the strings work in harmony.
Today, metal frames have been replaced with man-made organic fibres like Kevlar, graphite and epoxy resin with reinforced boron carbide. Professional racket heads have grown by 75% since the 1970s. Rigid frames can propel the ball up to 30% faster and thermoplastic dampers in the shaft absorb vibrations and reduce the risk of "tennis elbow" injury.
Even if the dazzling statistics and physics jargon fail to impress, companies resort to name-dropping.
That's all well and good for tennis manufacturers but the International Tennis Federation is worried.
The sport's governing body says that space-age materials threaten the spirit of the game, creating super-fast servers like Greg Rusedski, whose famous 140mph serve is almost impossible to return.
But there may be little the ITF can do. The group admits it spends more time debating racket technology than any other issue. By the time the organisation makes a definitive ruling, sports scientists are likely to have served yet another technological ace.