After you decide which style of e-bike you want, consider the class. In the U.S., there are three classes defined by the type of assist and how fast the motor will propel you. Most electric bikes sold are class 1 or 3. Class 1 bikes have a motor (max 750w) that assists while you’re pedaling, up to 20 mph. Class 3, also known as “speed pedelec,” can also have up to a 750w motor, but it can assist you up to 28 mph. Both are allowed in most states and cities without requiring a license. Class 2 models have throttles that don’t require the rider to pedal in order to get a boost. They’re allowed on most streets, bike lanes, and paths, but are less popular than the other classes and not covered much here (because not only do we still love to pedal, we also prefer the greater distances that pedal-assist bikes can cover).
The Freedom’s motor is more powerful than the VanMoof Electrified S — 350w vs 250w — but the VanMoof is technologically superior, with touch-sensitive display, enhanced security system, and an “invisible” lock built right into the rear hub. The Dutch-made bikes are also more expensive: VanMoof’s Electrified X2 and S2 list for a discounted $2,598, while Wing’s e-bikes are available now for an “early bird” price of $1,295; if you order later, it’ll cost $1,695 — which is still almost $900 less than the VanMoof.
Geared Hub Motors – Most pre-built e-bikes use brushless geared hub motors. These motors have internal planetary gears that help transfer power from the motor to the wheel. Because of the internal gearing, these motors provide excellent torque but are limited in top speed. On the plus side, the improved torque means better take-off power and hill climbing ability. Plus, less wattage is required to get the motor turning and they’re typically small and lightweight. On pre-built e-bikes, these motors range from 200w-500w and go up to 20mph. But some aftermarket kits can be as powerful as 1000w, with increased top speeds and huge amounts of torque (ideal for extremely hilly terrain). Besides lower top speeds, these motors tend to be expensive and it’s possible the gears will eventually wear out and need to be replaced (this is highly unlikely, they las quite a long time). Good examples are Ancheer bikes.
Range is a key consideration with e-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.[36][37] Some manufacturers, such as the Canadian BionX or American Vintage Electric Bikes,[38] have the option of using regenerative braking, the motor acts as a generator to slow the bike down prior to the brake pads engaging.[39] 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. E-bikes developed in Switzerland in the late 1980s for the Tour de Sol solar vehicle race came with solar charging stations but these were later fixed on roofs and connected so as to feed into the electric mains.[40] The bicycles were then charged from the mains, as is common today. While ebike batteries were produced mainly by bigger companies in past, many small to medium companies have started using innovative new methods for creating more durable batteries. State of the art, custom built automated precision CNC spot welding machines[41] created 18650 battery packs[42] are commonly used among Do-it-yourself ebike makers.
“Changes in production and consumption patterns are a crucial element of the sustainability agenda. Communication between product developers and users, and user integration in product development, can serve as a means for organizational as well as individual learning processes, resulting in sustainable product development. [...] Improved methods, such as INNOCOPE (innovating through consumer-integrated product development), tested in this study with a cycle manufacturer and resulting in a new product, a pedelec, are needed for effective communication, activating consumers and enabling them to promote sustainability goals. Through co-operative product development processes key factors facilitating and obstructing the adoption of sustainable innovations may be identified. Such processes can enhance the emergence and diffusion of sustainable product innovations and different forms and bodies of knowledge can be combined. Integrating users' contextual everyday knowledge of the product with the technical knowledge of companies may lead to mutual learning, technical innovations and changes in consumer behaviour.” (Hoffmann, 2007).
Attitudes to electric bikes have changed in recent years. For a long time they were seen by cyclists as 'cheating' and by non-cyclists as being just like a bike, but uglier and far more expensive. This new breed of best-in-class electric bikes feel more natural, look more normal, and people are coming around to the idea that a ride with the convenience of a bike but without all the sweat and effort is a Very Good Thing. 

If you are a regular bicyclist who wants to add some excitement to your rides or wants some help with those hills, a full sized electric bike is the way to go. If you are considering a bike as a means of transportation more than an outlet for amusement, then a smaller, folding electric bike is the convenient choice. In each category, consider the speed and range you want, as these factors impact price.
It is very important that sensors work well and that they are integrated/tuned for good usability. Although ebikes do need some initial mental adjustment from riders, some model do much better then others, e.g. most testers seem to prefer the TDS Impluse over the Stöckli E.T. over the Stromer (which model?) with respect to reactivity. Of course, usability is subjective and some people may prefer one behavior over an other. However, cheap bikes may be just plain bad and this is why test driving is important.
Before you start shopping around for a new e-bike, the first thing you should ask yourself is, “how do I plan on using an electric bicycle?” How far do you plan on traveling? What type of terrain will you be traveling on? How much assistance do you need? Do you plan on pedaling – or do you want the bike to do all the work? Is this bike for daily commuting or casual riding? How fast do you need to go?
Parliament has decided to approve the speed pedelec – a type of super electric bike that can reach speeds of up to 45 km/hour – for riding on cycle paths. Danish Parliament has decided that as of July 1 2018 those operating the super bikes only need to have turned 15 and wear a helmet, while the licence and number-plate demands will no longer be in play. [38]