Rear-Mounted Hub Motor, installed on the rear wheel, are more common on pre-built bikes because they’re easily installed at the factory. For a conversion, it’s a little harder to install than a front hub motor because of the chain, gearing and derailleur. Plus, you may be limited to a 6 or 7-speed freewheel. However, rear wheel drive will provide more torque and is less noticeable than a front hub.
There is however still confusion over the various legislations involving Electric Bicycles. This stems from the fact that while places like the US and Canada offer some Federal regulation, the legality of road use is left to the various States or Provinces and then complicated further by municipal laws and restrictions. Further more there are a range of classifications and terms describing them, "Power-assisted bicycle" (Canada) or "Power assisted cycle" (United Kingdom) or ”Electric pedal assisted cycles” (European Union) or simply "electric bicycles", and as such in some cases have varying laws according to their respective classifications in some places.

To operate a motorized/electric-assisted bicycle on the streets or highways a person must have a valid driver’s license or a motorized bicycle permit. A person under the age of 16 operating a motorized/electric-assisted bicycle under a motorized bicycle permit is subject to restrictions of no passengers (a parent or guardian my ride if the motorized/electric assisted bicycle is equipped with a seat and footrests for a passenger), no night driving, driving on any highway marked as an interstate, must wear a helmet, foot rests for passengers (if designed for passenger(s). A motorized bicycle permit is available to persons of at least 15 years of age who have passed the motorized bicycle test or passed a motorized bicycle course. A motorized bicycle would need the same coverage as a motorcycle would in this state. An electric-assisted bicycle would not need coverage.
During the course of its evolution, the Specialized Levo has helped shape the world of eMTBing. When it was introduced, it set the benchmark in riding dynamics and integration. Now Specialized has completely redesigned the bike and put it on 29″ wheels. The integration has been improved yet again, the battery capacity has been increased and the handling has been refined. We were thrilled with our first test ride. Anyone looking for a new bike next year for maximum trail performance should definitely take a closer look at the new Levo! We’re already looking forward to our big group test of the best bikes of 2019 early next year.

Whether squeezing onto the 4 train or pedaling through Lower Manhattan, I notice a few curious glances at the bike with the big battery in the center of the frame. This is not surprising; e-bikes are huge practically everywhere but the US. According to the latest figures from the Confederation of the European Bicycle Industry, e-bike growth in the UK is up from 40,000 units in 2016 to 63,000 in 2017.
Electric bikes are becoming a convenient and fun way to commute around a city, but they can be pricey. The average e-bike can cost $3,000, with some models getting up to $5,000 or more. But these prices are dropping, as new models come onto the market — and if you don’t mind giving up some of the glossier, high-tech features like embedded digital displays, retractable cable locks, and and theft tracking and recovery, you can find a really good quality e-bike for under $1,500. 

Even with cheaper or heavier bikes, once you accept that you are really meant to pedal gently and let the motor do the work, non-speed freaks will get into it. E-bikes are great for commuting and for places that aren't pancake flat. They'll pull you away from the lights quickly, iron out hills and stop you getting sweaty, so you can bin the Lycra and ride in jeans, a suit, or a winter coat.
A "class 1 electric bicycle," or "low-speed pedal-assisted electric bicycle," is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 20 miles per hour. (2) A "class 2 electric bicycle," or "low-speed throttle-assisted electric bicycle," is a bicycle equipped with a motor that may be used exclusively to propel the bicycle, and that is not capable of providing assistance when the bicycle reaches the speed of 20 miles per hour. A "class 3 electric bicycle," or "speed pedal-assisted electric bicycle," is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, (no throttle) and that ceases to provide assistance when the bicycle reaches the speed of 28 miles per hour, and equipped with a speedometer. Local government ordinances are allowed to permit or ban any class of electric bicycles on dedicated bicycle paths and trails, with Class 1 & 2 permitted, and Class 3 banned, by default.

An electric bicycle also known as an e-bike is a bicycle with an integrated electric motor which can be used for propulsion. Many kinds of e-bikes are available worldwide, from e-bikes that only have a small motor to assist the rider's pedal-power (i.e., (pedelecs) to somewhat more powerful e-bikes which tend closer to moped-style functionality: all, however, retain the ability to be pedalled by the rider and are therefore not electric motorcycles.

An electric bicycle is a bicycle with an electric motor used to power the vehicle, or to assist with pedaling. In many parts of the world, electric bicycles are classified as bicycles rather than motor vehicles, so they are not subject to the same laws as motor vehicles. Electric bicycles are one type of motorized bicycle. However, electric bicycles are defined separately and treated as a specific vehicle type in many areas of legal jurisdiction.
The federal Consumer Product Safety Act defines a "low speed electric bicycle" as a two or three wheeled vehicle with fully operable pedals, a top speed when powered solely by the motor under 20 mph (32 km/h) and an electric motor that produces less than 750 W (1.01 hp). The Act authorizes the Consumer Product Safety Commission to protect people who ride low-speed electric vehicles by issuing necessary safety regulations.[63] The rules for e-bikes on public roads, sidewalks, and pathways are under state jurisdiction, and vary.