The way they work is pretty simple: The motor kicks in with extra assist when you pedal, and there are different levels of assistance. That's it. Just turn it on, pedal, and go! You can also turn the assist mode off and ride it like a regular bike. And e-bikes stop assisting at a certain speed (in the U.S., it's 20 mph or 28 mph depending on class) for safety, of course.
Certainly not for the entry-level e-bike buyer, those who need to strap cargo to their back now have a new option with the Riese & Muller Load option, with full cargo space on the front of the bike. While over $6,000, the full-suspension bike has adjustability to allow for differing loads. Safety features include LED headlights and premium components abound.
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.