In a friction drive motor, a small, solid wheel rotates against the side of the tire in order to drive it. The first motorcycles used the same concept, with a motor mounted above the front wheel. The problem is that the drive rubs at the side of the tire. It's inefficient, and it quickly wears the sidewall away. Tires need to be replaced every couple hundred miles. For this reason, you'll seldom see electric bikes with this type of drive anymore.
If you have dynamo-powered bicycle lights, you already own an electric-powered bicycle! Consider: as you pump your legs up and down on the pedals, you make the wheels rotate. A small dynamo (generator) mounted on the rear wheel produces a tiny current of electricity that keeps your back safety lamp lit in the dark. Now suppose you could run this process backward. What if you removed the lamp and replaced it with a large battery. The battery would kick out a steady electric current, driving the dynamo in reverse so that it spun around like an electric motor. As the dynamo/motor turned, it would rotate the tire and make the bike go along without any help from your pedaling. Hey presto: an electric bike! It may sound a bit far-fetched, but this is more or less exactly how electric bikes work.
An e-bike is identified as a "motor assisted cycle" (MAC) in British Columbia, which differs from electric mopeds and scooters, which are "limited-speed motorcycles." Motor assisted cycles must: have an electric motor of no more than 500 W; have fully operable pedals; not be capable of propelling the device at a speed greater than 32 km/hr [19.9 mph]. The engine must disengage when (a) the operator stops pedaling, (b) an accelerator controller is released, OR (c) a brake is applied. A driver's license, vehicle registration, and insurance are all not required. A bike helmet must be worn.
State law defines a motorized pedalcycle as a motor-driven cycle equipped with operable pedals, a motor rated at no more than 1.5 brake horsepower, a cylinder capacity not exceeding 50 cubic centimeters, an automatic transmission, and a maximum design speed of no more than 25 miles per hour. Subchapter J of Publication 45 spells out the vehicle requirements in full.
Maryland defines an "electric bicycle" as a vehicle that (1) is designed to be operated by human power with the assistance of an electric motor, (2) is equipped with fully operable pedals, (3) has two or three wheels, (4) has a motor with a rating of 500 watts or less, (5) and is capable of a maximum speed of 20 miles per hour on a level surface when powered by the motor. (Senate Bill 379, approved by the Governor 5/5/2014, Chapter 294.)  This legislation excludes "electric bicycle" from the definition of "moped", "motorized minibike", and "motor vehicle", and removes the titling and insurance requirements required for electric bicycles under prior Maryland law.
Visually, the Pedego City Commuter Classic Electric Bike is stunning – a smart blend of yesteryear's style and today's technology. Pleasantly high handlebars, a sprung seat, and lovely Schwalbe Fat Frank tires make it very comfortable. Stopping is taken care of by powerful disk brakes, front and rear. Lights are included, as is a useful cargo rack. From an e-bike standpoint, the Pedego Classic City Commuter sports a reliable, hub-mounted motor driven by a 36-volt, 10-amp battery. There's a digital display with a trip computer, odometer, speedometer, pedal assist level, and battery charge information.
Range is a key consideration with electric bikes, and is affected by factors such as motor efficiency, battery capacity, efficiency of the driving electronics, aerodynamics, hills and weight of the bike and rider. The range of an electric bike is usually stated as somewhere between 7 km (uphill on electric power only) to 70 km (minimum assistance) and is highly dependent on whether or not the bike is tested on flat roads or hills. Some manufacturers, such as the Canadian BionX or American E+ (manufactured by Electric Motion Systems), have the option of using regenerative braking, the motor acts as a generator to slow the bike down prior to the brake pads engaging. This is useful for extending the range and the life of brake pads and wheel rims. There are also experiments using fuel cells. e.g. the PHB. Some experiments have also been undertaken with super capacitors to supplement or replace batteries for cars and some SUVS.
The drivetrain begins with pedals which rotate the cranks, which are held in axis by the bottom bracket. Most bicycles use a chain to transmit power to the rear wheel. A very small number of bicycles use a shaft drive to transmit power, or special belts. Hydraulic bicycle transmissions have been built, but they are currently inefficient and complex.
Toe-clips and toestraps and clipless pedals help keep the foot locked in the proper pedal position and enable cyclists to pull and push the pedals. Technical accessories include cyclocomputers for measuring speed, distance, heart rate, GPS data etc. Other accessories include lights, reflectors, mirrors, racks, trailers, bags, water bottles and cages, and bell. Bicycle lights, reflectors, and helmets are required by law in some geographic regions depending on the legal code. It is more common to see bicycles with bottle generators, dynamos, lights, fenders, racks and bells in Europe. Bicyclists also have specialized form fitting and high visibility clothing.
To be honest, this bike is really designed for city commuters or kids riding around the suburbs. The fact that it’s foldable will let you carry it on the bus, on the train or even on the plane. It’s just not designed for heavy riding, long distances or tough terrains. If you want something sleek and fabulous at a fraction of the cost of most other e-bikes, this baby’s for you.
As is the case with any e-bike assembled from Chinese parts, Wing has its share of clones that can be found for sale on sites like IndieGoGo and Kickstarter. For example, the Danish company Strom Bikes has a model for city biking that also looks incredibly similar to Wing’s Freedom — and is apparently several hundred dollars cheaper too. This is also commonly found with electric scooters, with startups buying Chinese-made models and rebadging them for sale in the US.
In some countries mixed systems, i.e. pedaling and/or using a throttle is legal. In EU countries and Switzerland this is not the case. I.e. you can buy an electric scooter, but this is not considered to be an e-bike in the moped / light scooter category. That kind of hack is probably more difficult, unless the original design has been modified to fit with (s)Pedelec specs. E.g. The Ezee models are of that kind and modifications to revert to the original does not seem to be too difficult...
Pedelecs are much like conventional bicycles in use and function — the electric motor only provides assistance, for example, when the rider is climbing or struggling against a headwind. Pedelecs are therefore especially useful for people in hilly areas where riding a bike would prove too strenuous for many to consider taking up cycling as a daily means of transport. They are also useful for riders who more generally need some assistance, e.g. for people with heart, leg muscle or knee joint issues.
Bicycles are popular targets for theft, due to their value and ease of resale. The number of bicycles stolen annually is difficult to quantify as a large number of crimes are not reported. Around 50% of the participants in the Montreal International Journal of Sustainable Transportation survey were subjected to a bicycle theft in their lifetime as active cyclists. Most bicycles have serial numbers that can be recorded to verify identity in case of theft.
Electric-assisted bicycles are treated as human-powered bicycles, while bicycles capable of propulsion by electric power alone face additional registration and regulatory requirements as mopeds. Requirements include electric power generation by a motor that cannot be easily modified, along with a power assist mechanism that operates safely and smoothly. In December 2008, The assist ratio was updated as follow: