How electric bicycles work?

How e-bikes work is by assisting your pedaling. Electric bikes are everyday bicycles with an added battery-powered electric motor. Although capable of pushing you along without your help, electric bikes perform noticeably better when you pedal. The average "couch potato" who normally rides at 10 mph can ride at 15-20 mph using the same effort.  He can also expect a range of 10 miles, with a recharge time of several hours. Do you remember that easy pedaling after you get your bike up to speed? That's the cruising feeling you get all the time with an electric bike.

Power, when activated by a switch on the handlebar (power-on-demand) or in response to your pedaling (ped-elec), gives you an immediate, nearly silent push. When you release the switch (or stop pedaling), the motor coasts or "freewheels" - like when you stop pedaling a regular bike. Standard bicycle hand brakes and gearing round out the controls.

"Power-on-demand" means just that - no pedaling required! Although all electric (or "electric-assist") bikes are designed to work with your pedaling, power-on-demand allows you to break the rule.  Most systems offer a variable speed control, although some are simply on/off (like the yellow switch pictured). A "ped-elec" won't deliver motor power unless it senses you are pedaling.  And it's "power output to pedal pressure" ratio  is often adjustable.   Most people find 400-watt motors adequate for their needs, although folks with steep hills may want more power.  Some bikes offer through-the-gearing power assist - i.e. the force of the motor goes through the bike's gearing system - which provides better hill-climbing and top-end speed than direct drive systems with the same size motor.

Electric bikes come in two basic designs - adaptive and purpose-built. The adaptive type starts with a bicycle and adds a drive system to it. A purpose-built e-bike is designed from the ground up. Adaptives are less expensive, less stylish, and may require installation (allow 3 hours if you're familiar with tools; otherwise your local bikeshop mechanic will charge about $75). Purpose-builts generate interesting designs and features (like brake-activated tail lights).  Users of both types enjoy easy acceleration, hill climbing, and cutting through headwinds. Rechargeable batteries, usually sealed lead-acid, provide power for the electric drive motors. Charging costs less than 5¢ of electricity from common 110 VAC wall outlets. Charging times vary widely due to charger output and battery capacity, but you can expect to recharge in less than 8 hours with most stock chargers.  Quick chargers are available.

Mopeds differ from e-bikes in that they generate more speed, risk, range, expense, pollution, and legal issues. Top speed of mopeds is limited by law to 30 mph.  Often, a driver's license and registration is required.  An electric bike, which by law is limited to a top speed of 20 mph, reduces the risk of serious injury.  It's shorter range of 8-20 miles is plenty for errands and short commutes.  E-bikes are the cleanest motorized vehicles - both in terms of air pollution and noise.  If you own a bike, you can motorize it for as little as $400.  Or buy a purpose-built e-bike for up to $3000.  Either way, you can ride your e-bike without a driver's license, vehicle registration, or insurance.