This killed me.. haha so good
oh man, I remember seeing a physical copy of that in a pro shop a long time ago. A very long time ago ...The 6.1 name is rooted in the stiffness index before it became a line of racquets.
From https://au.wilson.com/pages/the-history-of-the-wilson-pro-staff-tennis-racket:
STIFFNESS INDEX: In the late 80’s and early 90’s, Wilson’s engineers developed a system known as the “SI SYSTEM” where “SI” standing for “Stiffness Index”. This system is a measurement of a racket’s flexibility and stability. The 90’s graphic below paints a visual, but in a nutshell, the lower a tennis racket’s SI, the more stiff, while the higher a racket’s SI, the more flexible. Stiffer rackets produce more power while flexible rackets produce more control.
In Wilson’s current racket lines, Ultra is the most stiff at a 3.9si while Clash rackets are the most flexible, topping out at 11.2si. For reference, the most popular Pro Staff’s typically have measured around a 6.0si, which is considered an ideal blend of flexibility and stability. The new Pro Staff v13 line measures in at a 5.5si. All important to note as you look through every Pro Staff ever, as you’ll notice SI was used to differentiate the models in the 90’s and early 2000’s.
S.I. has also been referred to by Wilson as "Swing Index". High swing index numbers corresponded to longer swings and the opposite for low index numbers.The 6.1 name is rooted in the stiffness index before it became a line of racquets.
From https://au.wilson.com/pages/the-history-of-the-wilson-pro-staff-tennis-racket:
STIFFNESS INDEX: In the late 80’s and early 90’s, Wilson’s engineers developed a system known as the “SI SYSTEM” where “SI” standing for “Stiffness Index”. This system is a measurement of a racket’s flexibility and stability. The 90’s graphic below paints a visual, but in a nutshell, the lower a tennis racket’s SI, the more stiff, while the higher a racket’s SI, the more flexible. Stiffer rackets produce more power while flexible rackets produce more control.
In Wilson’s current racket lines, Ultra is the most stiff at a 3.9si while Clash rackets are the most flexible, topping out at 11.2si. For reference, the most popular Pro Staff’s typically have measured around a 6.0si, which is considered an ideal blend of flexibility and stability. The new Pro Staff v13 line measures in at a 5.5si. All important to note as you look through every Pro Staff ever, as you’ll notice SI was used to differentiate the models in the 90’s and early 2000’s.
I’m about a 2.1 right now.The 6.1 name is rooted in the stiffness index before it became a line of racquets.
From https://au.wilson.com/pages/the-history-of-the-wilson-pro-staff-tennis-racket:
STIFFNESS INDEX: In the late 80’s and early 90’s, Wilson’s engineers developed a system known as the “SI SYSTEM” where “SI” standing for “Stiffness Index”. This system is a measurement of a racket’s flexibility and stability. The 90’s graphic below paints a visual, but in a nutshell, the lower a tennis racket’s SI, the more stiff, while the higher a racket’s SI, the more flexible. Stiffer rackets produce more power while flexible rackets produce more control.
In Wilson’s current racket lines, Ultra is the most stiff at a 3.9si while Clash rackets are the most flexible, topping out at 11.2si. For reference, the most popular Pro Staff’s typically have measured around a 6.0si, which is considered an ideal blend of flexibility and stability. The new Pro Staff v13 line measures in at a 5.5si. All important to note as you look through every Pro Staff ever, as you’ll notice SI was used to differentiate the models in the 90’s and early 2000’s.
Is that you Jim?
