Rode over to a 55mph state route this morning going south for coffee on my 155cc, 2018, Liberty.
Waited for clear traffic and gave it the beans.*
I saw 64MPH on the speedo - tires properly inflated - probably - no wind, no breakfast. 265lbs, a touch over 6'3" - sitting bolt upright like a man reading the New Yorker on the loo. About as aerodynamic as a box of Rice Chex. Might have been 3 or 4 better than last tested - few yrs ago.
Big/wheel scooter stable.
Stig
* of course, this being Ohio I soon collected a tailgater out of nowhere. Blinding in my mirrors. I adjusted the L mirror - but one cannot do that at 60mph with the throttle mirror and a car in your tail light.