I am 6'. I started out with the 8", but the wind still hit the top of my head. Jumped up to a 12" and love it. I wear a 3/4 helmet and can hear my music just fine. Have to turn it down at times because it is to loud.
“Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats.”
― H.L. Mencken