It is my understanding that most electric motorcycle companies use the adopted "city cycle" standard when providing their advertised maximum range figure. That standard has a lot of stop and go riding, which I seem to recall averages out to about 30 mph during the cycle. So great for city scooters, but not so good for freeway-legal motorcycles. I think Zero's range estimates for "combined" city and freeway travel and for steady freeway riding are pretty reliable in perfect conditions with a solo rider, on level ground riding in calm wind and warm temperatures. But as we all know, most of our riding is not accomplished during perfect conditions.
Tesla uses 65 MPH. I think motorcycles should use the same standard. But as I said before, just tell me the useable capacity of the battery. No need for a range spec and there are too many variables to get an accurate range.
I like to keep my Energica screen on KWs. That way, I can see how much load I am putting on the battery. IIRC, it is a 11.7 KWH useable. So if I stay at a 11.7 KWH power draw, I should be okay for an hour of riding.
All this stuff can be figured out with simple math. No need for a range spec or battery charge times.
Use 5 times the KWH to figure out the freeway range. IOW, 11.7 KWH times 5=58.5 miles of freeway range.
Easy city riding is easier. Just move the decimal over one place. 11.7 KWH is 117 miles of range. Make adjustments for conditions (weather, weight and such) from there. Better than any range spec, IMO.
-Don- Reno, NV