It’s not a speed monster, thats for sure; I have a three-speed hub under the seat.
I don’t know the gear ratios, it just happened that way...
I could have used a few more gears for better power in low speed, starting uphill etc.
Top speed depends heavily on various conditions, me for example....
With this setup and the electric assist the cruising=top speed is about 25 km/h (15mph).
In my case there is no need going faster, traveling on potholed roads and/or sharing bicycle lanes with ”ordinary” bikes. If faster then suspension, better brakes etc.
//hp