I wear Rx glasses, sorry, no goggles.
On the MC, I wear a 3/4 helmet with a face shield. 90 MPH down the highway, no problem.
On the MB, I wear a DOT half helmet no face shield.
20 MPH is a good speed on my MB.
Any faster and you have to pay too much attention to the bike and the road anyway and you can't see all the people smiling at you. Actually, 15 is better. Coaster brakes work good at 15.
After all, it's a lot of work to pedal at 15 right?
I rode past 3 cops today at 15-20, didn't raise an eyebrow -