Usual speed limitation:
36V <40km/h (250W motor)
48V <55km/h (500W motor)

Usual riding range with load limitation:
36V 12Ah : 20km
36V  18Ah : 40km
48V  12AH  : 15km
48V  21Ah  : 40km

Speed & range governed by Voltage, Ampere Hour & Wattage