I'm not that optimistic. I don't think the drivetrain is up to high efficiency, even if the gearing and aero were all sorted out.
Cruise rpm is about 3500 at 60 mph.
This thing is sposta weigh about 700 lbs., so with fuel and me it's pushing 1/2 ton. I should try to figure the frontal area- it's gotta be massive. And to make matters worse, I really need to fit the taller aftermarket windshield (that's sitting in MN
) as now I need to crouch down to get out of turbulence. Of course even better from an aero perspective would be to lower the seat so that the std windshield becomes the right height for me. But the seat is nice and cushy and I ain't gonna mess it up. Plus, my legs will only fold up so far.
I'd expect a noticeable gain if auto tires were fitted. It just doesn't seem to coast all that well and I don't think aero is the culprit. I know the brakes aren't the culprit either- well, any worse than any old disc brake is.
I think averaging a sorta consistant 40 would be a miracle.