How do racket strings perform, why do they break and how often they should be replaced ???

 Some string facts;

• Squash strings are made of natural gut, nylon or aramid fibre.
    
• Strings are always losing tension because the inner molecules are continually moving apart and this “Creep” continues until it breaks.
    
• Strings break for two reasons – when they rub against each other and wear away until one of them gets too thin and breaks, or when the string cannot stretch enough on ball impact, usually near the edge of the racket.
    
• Strings work by absorbing the incoming ball impact and then sending it back with as much velocity as possible. The more elastic the string, the more speed on the return journey.
    
• Thinner strings will be more elastic, will break quicker, thicker strings will be generally more durable but less able to return the ball fast.
    

String Materials

Natural Gut – At one time the ONLY string about and rarely used these days due to its high cost and short life. It comes from the cow and goes through a long laborious process (hence the expense) where it is cut, stretched, dried, twisted, polished and finally given a polyurethane coating to protect it from harmful moisture that swells the fibres and unravels everything.

Some professionals like natural gut because it performs best of all until the moment it breaks, because the ongoing “creep” effect is almost nil and the shots will retain their accuracy.

Nylon –Accounts for about 99% of all strings, is not affected by water, is not too expensive and comes in either a “multifilament” that copies natural gut or a “solid core” nylon that will perform well until it breaks.

Many professionals use this cheaper solid core nylon a lot as they will restring often anyway due to the “creep” effect causing them to lose control. Nylon is a material that bonds onto other nylons very well, so it is easy to blend together various combinations of elastic fibres and durable wear layers to give different playing experiences.

There have been some exciting new strings come onto the market which offer high playability with good durability. The thinner gauge strings such as Tecnifibre X-One and Ashaway’s Powernick18 are good examples of either very good playability with good durability or good playability with very good durability.

What you gain with one string, you tend to lose something else. Each will have their own following because they suit different types of play. 

Polyester – Designed for tennis players who break strings each week, either because they hit the ball so hard, maybe with heavy topspin or because they play on clay courts where the clay particles chew up the softer nylon.

Durability is the advantage and no polyester has yet been developed that will allow a reasonable amount of playability for the much lighter squash ball.

Aramid Fibre – Usually called Kevlar, an ultra strong string that is used for body armour, not good for the arm and is rarely seen.

Fischer have used this string for the central six mains in some rackets.  
 

String Tensions

Think of yourself jumping up and down on a trampoline. In the middle, where the bed is softer, your feet sink in deep into the trampoline bed and you can get really good height but no real confidence of where you are heading!

If you stray out towards the edge of the trampoline bed you end up with little bounces as the bed is stiffer, cannot get so much height but feel more in control.

This is exactly what happens on a racket stringbed. A low tension will allow the ball to sink in deep, create POWER and propel it a long way. High tension means more CONTROL over the flight of the ball.

This is because the ball spends less time on the strings (ball dwell) before leaving.