Strange how you all answered with top speed numbers when I mostyly scare the hell out of my pillions with lean angle and corner speed. No I haven't ever dragged knee with a pillion (just cause it is hard to hang off with your wife shrink wrapped to your back) but I do let her feel the lean, step kids too.
She rode in a straight line up to my 600's limit 145-150. Had no adrenaline at all. So she asked for a road race ride and I obliged.