Calculating the highest, possible speed you can get

Edit: Another way to calculate it:

speed: v(km/h)=n(r/min)*2rπ(m)*60/1000, n=load RPM, r=tire radius.

For speed less than 100KPH, consider the Windage Resistance & Rolling resistance.

the load RPM is appr 0.9 * no-load RPM. v(km/h)=0.9*n(r/min)*2rπ(m)*60/1000

For over 100KPH, V=0.85*RPM*2rπ*60/1000