The bicycle's invention has had an enormous effect on society, both in terms of culture and of advancing modern industrial methods. Several components that eventually played a key role in the development of the automobile were initially invented for use in the bicycle, including ball bearings, pneumatic tires, chain-driven sprockets and tension-spoked wheels.[10]
The body is made from light and durable aluminum. The handlebar comes with simple controls to let you accelerate, brake, monitor battery life, operate headlights and of course…sound the horn. There’s even an USB point that will let you charge your iPhone or Android on the go. The bike can reach a top speed of 10mph. Feel the wind in your hair as you zoom up and down hills and past all that city traffic…
Would an e-bike that used a trailing generator to power the electric motor still be considered an e-bike? The purpose of the generator is allow greater distances to be traveled and all day riding. The gen-set that I am looking at uses a 49 cc gas engine with a 12 volt generator, this would be from the ground up build using a 1 hp electric motor. This seems to stay within the state laws of AZ. where I reside. Thanks for your thoughts.
Both land management regulators and mountain bike trail access advocates have argued for bans of electric bicycles on outdoor trails that are accessible to mountain bikes, citing potential safety hazards as well as the potential for electric bikes to damage trails. A study conducted by the International Mountain Bicycling Association, however, found that the physical impacts of low-powered pedal-assist electric mountain bikes may be similar to traditional mountain bikes.[68]
Step-throughs were popular partly for practical reasons and partly for social mores of the day. For most of the history of bicycles' popularity women have worn long skirts, and the lower frame accommodated these better than the top-tube. Furthermore, it was considered "unladylike" for women to open their legs to mount and dismount—in more conservative times women who rode bicycles at all were vilified as immoral or immodest. These practices were akin to the older practice of riding horse sidesaddle.[citation needed]
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

Chart: Electric bicycles are rapidly becoming popular. This chart shows the growth in sales of what the manufacturers refer to as "electric power-assisted cycles (EPACs)" in European countries over the last decade. Over 1.6 million electric bikes were sold in Europe in 2016 alone, which is about 7 percent of total European bicycle sales. What this chart doesn't reveal is that the bikes are much more popular in some countries than others: four countries accounted for 70 percent of all the sales (Germany, 36 percent; the Netherlands, 16 percent; Belgium, 10 percent; and France 8 percent). Data sourced from the report "European Bicycle Market: 2017", courtesy of CONEBI (Confederation of the European Bicycle Industry). These are the newest figures available at the time this article was last updated (September 2018).
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.[55] Subchapter J of Publication 45 spells out the vehicle requirements in full.

I like this little electric "scooter" a lot. I do think the rear wheels should be a bit further apart for added stability. I have also found it is too easy to "spin out" the front driver wheel when going up an incline or crossing a grass area. The user and assembly manual is minimal and could use considerably more information and more and better illustrations.

The two most common electric motor styles used in today’s e-bikes are hub motors and mid-drive motors. The Freedom uses a hub motor, which was located in the center of the rear wheel. Hub motors typically don’t offer the same natural maneuverability as the increasingly more common (and more expensive) mid-drive motors because their weight is concentrated in the rear of the bike. It can be jarring when the motor prevents you from going faster than the allotted speed, especially when cruising downhill, but 20 mph is the legal maximum for e-bikes in the US. (In the EU, it’s even lower: 25 km/h, or 15.5 mph.)

The basic shape and configuration of a typical upright or "safety bicycle", has changed little since the first chain-driven model was developed around 1885.[7][8][9] However, many details have been improved, especially since the advent of modern materials and computer-aided design. These have allowed for a proliferation of specialized designs for many types of cycling.
In the United States electric bikes have seen slow but steady growth since the late 90’s and as a result, in 2001 congress was lobbied and passed the first and only bill to define ebikes in federal law. This law, 107-319, exempts electrified bicycles with operating pedals using motors under 750 watts limited to 20 mph from the legal definition of a motor vehicle.2.
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 electric bicycle dubbed Zike.[7] The bicycle included Nickel-cadmium batteries that were built into a frame member and included an 850 g permanent-magnet motor. Despite the Zike, in 1992 hardly any commercial electric bicycles were available. It wasn’t until 1998 when there were at least 49 different bikes. Production grew from 1993 to 2004 by an estimated 35%. By Contrast, according to Gardner, in 1995 regular bicycle production decreased from its peak 107 million units. Some of the less expensive electric bicycles used bulky lead acid batteries, whereas newer models generally used NiMH, NiCd and/or Li-ion batteries which offered lighter, denser capacity batteries. The end benefits usually varied from manufacturer; however, in general there was an increase in range and speed. By 2004 electric bicycles where manufactured by Currie Technologies, EV Global, Optibike, Giante Lite, Merida, ZAP.

Some electric bikes claim to use a neat trick called regenerative braking. If you start pedaling the bicycle or going downhill, the spinning wheels turn the electric motor in the hub in reverse and start charging up the batteries. In practice, regenerative braking is nowhere near as useful on an electric bicycle as it is on an electric train or car. An electric bike has much less mass and velocity than either a train or car, so it never gains (or loses) anything like as much kinetic energy when it starts and stops. You'd have to go down an awful lot of hills to charge up the batteries completely and that's usually not practical. And what's the point in pedaling the wheels simply to charge the battery? You might as well have bought an ordinary bicycle to start with!

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.
Power-assist: Also known as pedal-assist bikes, these are the bicycle equivalents of hybrid cars: they're designed to be pedaled quite a lot of the time and electrically powered either when you're tired or when you feel like a bit of electric help (when you're going up hill, for example). Unlike full-power bikes, they don't have hub motors; instead, there's a separate electric motor mounted near the rear wheel and driving it either through the gear sprocket or simply by pressing against the rear tire. Where a hub motor is difficult or impossible to pedal without any power (because you're effectively turning it into a generator), power-assist motors turn easily with little or no resistance when you pedal. That gives power-assist bikes much greater range than hub-motor ones (as much as 80–145km or 50–90 miles).
This is an unofficial guide to the laws governing electric bicycles in the United States as of 2016. It was contributed by a guest writer The Smart Ped`aleck who was paid and remains unaffiliated with any electric bicycle company. It may be updated ongoing and is cited throughout with reference links and attributions at the end. It is designed to be an entertaining starting point for understanding the space, digging deeper and in turn choosing the best electric bike platform for your needs.
Haibike ships the HardNine with 29-inch tires, 180-millimeter hydraulic disc brakes, a 100-millimeter front suspension fork, and a nine-speed Shimano shifting system. The bike’s LCD readout is affixed to the handlebars and displays the current speed, level of charge, remaining range, and current pedal assist mode. The company says the battery can be completely recharged in just four hours, minimizing downtime between rides.