To qualify as an electric-assisted bicycle under state law they need to have a seat and fully operable pedals for human propulsion, meet federal motor vehicle safety standards, an electric motor that has a power output of not more than 1,000 watts, maximum speed of not more than 20 mph (electric motor and human power combined), disengages or ceases to function when the vehicle’s brakes are applied, two or three wheels
China's experience, as the leading e-bike world market, has raised concerns about road traffic safety and several cities have considered banning them from bicycle lanes.[2] As the number of e-bikes increased and more powerful motors are used, capable of reaching up to 30 miles per hour (48 km/h), the number of traffic accidents have risen significantly in China. E-bike riders are more likely than a car driver to be killed or injured in a collision, and because e-bikers use conventional bicycle lanes they mix with slower-moving bicycles and pedestrians, increasing the risk of traffic collisions.[2]
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.
As of May 19, 2009, Nevada amended its state transportation laws to explicitly permit electric bicycles to use any "trail or pedestrian walkway" intended for use with bicycles and constructed with federal funding, and otherwise generally permits electric bicycles to be operated in cases where a regular bicycle could be. An electric bicycle is defined as a two- or three-wheeled vehicle with fully operable pedals with an electric motor producing up to 1 gross brake horsepower and up to 750 watts final output, and with a maximum speed of up to 20 miles per hour on flat ground with a 170-pound rider when powered only by that engine.[106]
Torque sensors and power controls were developed in the late 1990s. For example, Takada Yutky of Japan filed a patent in 1997 for such a device. In 1992 Vector Services Limited offered and sold an e-bike dubbed Zike.[9] The bicycle included NiCd batteries that were built into a frame member and included an 850 g permanent-magnet motor. Despite the Zike, in 1992 hardly any commercial e-bikes were available.
Firstly there's a magnetically-fired locking pin in the rear wheel, triggered by kicking a button on the hub. This is fairly secure in itself and almost impossible to remove without destroying the bike. In London, we'd pair it with a more traditional bike lock so there's a more obvious visual deterrent, though a LED matrix screen on the frame does issue a warning to would-be tea-leafs.

Introduction A quick of note of my experiences riding a Moustache Dimanche eBike, kindly provided by Fully Charged, on a spectacular 4 day trip, coast-to-coast across Italy. Overall, an amazing experience in terms of the quality of the ride, the scenery and the new experience of quite painless climbing of the many steep hills. I … Continue reading The joys of crossing Italy coast 2 coast on an eBike – by Andreas Credé

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.