High speed windscreen I too have the tall screen and the lowers and on the way back from Traverse City on U.S. 23 south between Milan, Mi and Dundee, Mi I ran mine to the ignition limiter in 5th (eating a V-Rod) that got frisky. I believe that's around 140 or so and the windshield didn't even quiver nor did the lowers. I did however. Next exit I had to get off and use the mens room.
I have this thing for terminal velocity whether it's a farm tractor, snowmobile, bike or my lawn mower. When exploring terminal velocity on a public road you have to keep an eagle eye out for Barney Fife.
I'm exhibiting diligence in not getting a full power tune installed though I'd like to do a radar run and see what she'd do on top end. I'd imagine that the limiting factor with a full power tune would be the windshield. I know 140+ is obtainable but do get an additional 30 and squaring the wind resistance factor makes it non practical with a windshield installed. I can't imagine hitting a bee or horsefly or any bug at 170 without a windshield. It would be tantamount to a big sucker punch right in the kisser.