ERSA Pro Stringer Magazine 6 - 2019 prostringer 6-2019 | Page 25

www.ersa-stringers.com STRING TEST ISOSPEED PROFESSIONAL 1.20mm - STRING TEST   If you want to try something different from all the other strings on the market, something "hybrid", with a multifilament ribbon structure, with the low dynamic stiffness of a multifilament string but with the static stiffness of a monofilament string, you can't do anything else but test the classic Isospeed Professional. This string is built using an uncommon material for string production, polypropylene, bonded in a unique structure that permits the ribbons to move within the core increasing power and the resilience response of the string. A final pre-stretch treatment and wax coating give the filament good stability and the ability to generate a lot of spin for a "multifilament" hybrid string. The static stiffness is quite high, higher than other multifilament at the same tension going from 0.80 to 0.90kg/mm; the graphic trend is almost linear and similar to natural gut more than a polyammide-polyurethane string giving the string a fast response and a very lively ball exit from the stringbed. The dynamic life is near to the top (25-30 hours of play) and you can use the string until you break it or when the tension loss has become significant. 25 ERSA PRO STRINGER // ISSUE 6-2019