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Poly . Zero Poly
Poly , Zero Poly™ and the Dynamics of Spin
By Steve Crandall Vice President , Sales & Marketing Ashaway Racket Strings
In tennis these days--much like politics--spin is all the rage . Everybody wants to improve their " up and down " game , and play like the top pros with " heavy balls " that drop like stones just inside the base line . And to generate that spin many are also emulating the pros by using the same " high tech " high-performance polyester strings , aka " gut on steroids ." But what they ' re fi nding , unfortunately , is that polyester strings don ' t work as well for them . They feel like they have to work much harder with these strings to get less ; and get worked over pretty hard by them in return . One fellow likened playing with them to " hitting a brick wall with a baseball bat ."
So is polyester all it ' s cracked up to be when it comes to spin , and is it the right string for you ? The answer is yes , and no .
Previously , we talked about how stiff polyester strings are and how--in addition to rattling your teeth when you hit the ball with them--they actually generate less power than other string materials like gut and the new Zero Poly™ materials like Polyketone / Zyex ®. So then , how is it possible for a string that generates less power to also generate more spin ?
Back in 2011 , Crawford Lindsey and company at Tennis Warehouse University studied spin extensively , and published a number of highly technical reports on the mechanics and physics of spin on the TWU website . Their comparative study , Which Strings Generate the Most Spin , concluded that polyester strings do indeed generate more spin : on average , about 25 % more than nylon and 7 % more than natural gut . But they also point out that :
1 . The player has by far the larger role in generating spin . Racquet head speed , angle of racquet , and angle of swing basically trump all other considerations . Other non-equipment factors include incoming ball speed , angle and amount of topspin . 2 . While string material , tension and stringing pattern do play a role , the key factor in this regard is lateral string movement and snap-back . Polyester simply moves laterally more easily than nylon or gut , and thus produces more spin .
But , they ask in a follow-up report , String ' Snap-Back ' and Spin , " What is it about the string / material that makes it move and stretch laterally ? The candidates from TWU string properties testing would suggest stiffness , tension loss , and slipperiness as the main candidates . Polyester is stiffer , loses more tension , and is slippery . The stiffer material may be more able to overcome inter-string friction or move faster ; the lower tension decreases interstring friction enabling more movement ; and slipperiness ( low coefficient of friction--COF ) also lessens inter-string friction . These may all act in interactive combinations to facilitate string movement and snap-back ."