The Stromer is tailored for riders of all types and skill levels. The patented "dual power system" allows for power-on-demand riding (limited to no pedaling), with a top speed of 20 mph and a range of up to 20 miles. Feel like pedaling? Just switch to pedal-assist mode and let the state-of-the-art torque sensor augment your pedaling efforts with motor assistance. Pedal-assist mode allows for 45+ mile range. Charging is easy with their patented removable battery system. Simply unlock the internal battery storage case on the frame, remove the battery, and charge up with any 115V power outlet (onboard charging is also available).
E-bikes mostly use motors and battery options from a few major suppliers: Bosch, Yamaha, Shimano, and Brose. A few other brands exist, but are less reliable or powerful. Some, like the Yamaha system, have more torque and others are quieter. But generally all four make good options. Look for motor output (in watts) which will give you an idea of total power. But watt hours (Wh) is perhaps a better figure to use—it takes into account battery output and life to give a truer reflection of power.