Jack Kramer ProStaff…update!
Many of you have probably never seen a Jack Kramer ProStaff racquet. That is one advantage I have by being old! This is the definitive wooden racquet produced by Wilson many years ago and to find a good one is rare. I have a couple brand new ones but I didn’t expect to see two (2) come in for stringing!
I put Tecnifibre MultiFeel 16 gauge in both at a reference tension of 45 pounds. These are, by the way, for a really good junior player to use for stroke production training. He loves them!
To put these racquets into perspective here are some specifications compared to the new Wilson BLX ProStaff Ninety. I will call these the “Kramer” and the “Ninety”. The Kramer is 27 inches long, ditto the Ninety. The Kramer weighs 13.3 ounces, the Ninety 12.6 ounces. The head size of the Kramer is 69.6 square inches and the Ninety is 91.1 square inches.
The Kramer has a stiffness of 24.0! Yes, I checked it several times. The Ninety has a stiffness of 63.0. Both have an ERT SBS of 36 but the Kramer has an effective stiffness of 16.1 and the Ninety an effective stiffness of 29.9! It is easy to see why there were fewer arm issues during the wooden racquet era.
The down side of flexibility is the reduction of power available from the racquet. The Kramer checks in at 19 compared to 46 from the Ninety.
So, it is not hard to see why new racquets are better suited to most players. The ball will make it to the net!