Originally Posted by SandV
Noooo, the K Factor 90 stiffness is 67.
Fed's racket checked for stiffness on a RDC machine came out to 65. http://www.hdtennis.com/grs/pro_racq..._wilson_n.html
Wilson PS (2014) 90 - Wilson Pro Overgrip - 12.9 ounces
Wilson Gut 16 / Luxilon ALU Power Rough 16L 50/47 pounds