I ran across an intresting experiment, these guys built a test platform that they mounted on the mirror bracket of a pickup to test how much force was required to move a flight control
it had a deflection gauge and a scale hooked to the control horn they drove down a runway at speed up to 80mph I was suprised at how little force was reqired to hold it at 45 degrees I wish I had saved it
can't recall the numbers bit it was way less then what you hear people say you need