Added,,
Plan on leaving the governor in it, as the gearing is 4.86 - 1,, & the tires are 14.25+ O.D.
Mine on the GPS does 38.2 mph ''so far'',, & my gearing is 5 -1 , with the same back tire, & governor in it.
Fred's ought to hit 40 ''no problem'', with the governor still in.
Far as I' am concerned,, my bike is ''quick as Hell'' for a block or so,, & 38 - 40 mph on these little suckers is ''plenty'' fast.
Thinking Fred's is going to kick that up a notch or so,, plus his bike is going to be around 5 lbs. lighter than mine, plus he weighs around 40lbs. less than me.