Originally Posted by db10s
This sounds so cool... May I ask "how" do you do it? I'm overly intrigued.
You can use a Babolat RDC to test swing weight, balance point, flexibility, and string bed stiffness.
For spin, we shoot a ball at the string bed at varying angles/spins/paces and use a special camera that shoots at 240 FPS (or something absurd like that, can't remember off the top of my head.) There also is a machine that is kind of like a radar gun that measures RPM (revolutions per minute).
When we (and most people) product test, the idea is to have as much of the test controlled, so you can tweak specifics variables to understand their effect.
Durability is less exciting, but involves putting stress on products until they break.