Originally Posted by ChicagoJack
Cool. Thanks for the heads up. I figured that tension loss was a factor, I just had no idea the disparity, it's a huuge deal it would seem. I'm flowing the actual tension / pre test digits into the list now. I will keep the reference tension (62 lbs) and swing speed (fast) so that the parameters of the two indexes remain consistent. When I get those three sets of digits all stacked up, somebody a whole lot better at math than I am, ought to create some sort of formula to assimilate the implied meanings of the three factors (hint hint)
Nice work getting the actual testing tension into your table. It seems to me that, all things being equal, a copoly that loses less tension beats one that loses more. Unfortunately, the only copolys that hold tension at all well are the stiffer ones - 4G (the new champ), Bab Hurricane Feel, 4S, etc. If I used a really heavy racquet with high swingweight I would pair those with natural gut. But since I use a 12 ounce frame with moderate SW, and am always looking for some extra comfort and pop, I focus exclusively on the soft copolys. And one of the benefits of those is that you can raise the tension of the gut somewhat, which helps with snapback, I feel. I've been using budget guts strung around 55 pounds in a 95 and have found the gut to bag out and stop snapping back before it breaks, which is unacceptable
Probably I wouldn't have this problem with Klip or Pacific guts, but I would really like a slippery cross soft enough to string at 60 pounds, which is the tension where gut is the most powerful (highest energy return and fastest snapback).
BTW, the large number of nylon strings with low COF in your table is interesting. I think we can conclude that when strung fresh these guys would make great crosses with gut mains. But we know from the Japanese studies that notching kills the snapback mechanism, and as far as I know all nylon strings notch and dent. The possible exceptions might be the flat Gosen strings - Powermaster and Compositemaster.