Mike,
I'm 6' and went with the 16" screen. If you look at Robert's picture, there are 4 holes on each side of the actual screen that give you a bit of up and down adjustment. They also include some chrome plugs to put in any holes that are left open.... I started out with a National Cycles screen and it was like going from a Yugo to a Cadillac when I got the Windvest....