Like the Currie, the Rayos has a lot of torque, independent human and electric drive systems, and a drive system that freewheels when not in use. The electronics shut the motor off at 80% battery discharge to avoid a full discharge (which really shortens the life of lead-acid batteries). The Rayos is an 8-speed bike that uses standard bike parts. Seats, handlebars, brakes and other non-electric parts can be found at a supercenter or bike store. Electric parts can be obtained from Rayos dealers.
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).
For many bikes, battery range is more important that total power (because they're all pretty powerful). You want a bike that delivers a range long enough for your rides at the power levels you want. Most e-bikes will have three to five levels of assist kicking in anywhere from 25 percent of you pedal power to 200 percent boost. Consider how fast the battery takes to recharge, especially if you'll be using your bike for long commutes.