Originally Posted by treblings
thanks, i think i get that.
where does rough poly come in(as in alu power rough or msv hex,...)
in regard of spin? in the mains? is that what you mean by sharper?
Rough poly is exploiting the ball-string friction parameter. The higher this is, the greater the spin potential. The lower the string-string friction, the greater the spin potential. Interestingly, we have two counter examples to look at then using the same set of data. A stiffer string, according to TWU data, is more likely to be a better spin string. Thereby poly will provide more spin potential than synthetic gut or multifilaments. However, a moreelastic
string will also provide more spin potential. These two concepts are not the same. To make it more clear, let me define the two. Stiffness is the ability for a material to not deform or to resist deformation when under stress. Elasticity is the ability for the material to return to its original state after being deformed by stress. So, we're at an impasse: we want a string which does not deform under stress, but one which when it does deform, it returns to its original shape. This is why polyester is so popular for spin. It is very stiff, but yet it has a surprising amount of elasticity.
Once that elasticity is gone from usage, then the string's performance is lessened. If you have a rough string which can hold onto the ball while the string is deforming, you can return more energy to it. BUT! If the sliding friction is too high, or the friction trumps the string's elasticity, then it doesn't matter as much. That's why while natural gut is overall the best for spin next to poly, it still suffers from high string-string friction. Therefore, you want something with elasticity in the mains that bites onto the ball and something smooth in the crosses so that the mains can move more freely. This is the reasoning behind the gut/poly hybrid. If you put a rough poly main with a smooth poly cross, you can theoretically get similar results: you get great stiffness from the mains, and good ball-string friction, and low sliding friction just like with gut/poly.