There are individuals who claim to have lost considerable amounts of weight by using an electric bike. A recent prospective cohort study however found that people using e-bikes have a higher BMI. By making the biking terrain less of an issue, people who wouldn't otherwise consider biking can use the electric assistance when needed and otherwise pedal as they are able. This means people of lower fitness levels or who haven't cycled in many years can start enjoying the many health benefits E-bikes have to offer. 
The motor isn’t insanely powerful, but it gets you up to full speed quickly enough. I never felt like the bike was underpowered. The motor does make more noise than a lot of other hub motor bikes I’ve ridden though. There’s a definite whirrr to the motor caused by the internal plastic gears. While all geared motors will have some level of gear noise, this one stuck out more to me than others.
As long as you can do without some of the perks that pricier models offer—like a detailed display unit, integrated lights, and a torque-sensor motor—the August Live! LS is a solid, stable, comfortable, and really freakin’ cute (have you see those polka-dot fenders?) e-bike. Its 8-speed twist shifter, chopper-style handlebar, Touch Down Geometry (for a more laid-back ride), and three levels of assist keep this bike within the realm of “cruiser.” But with a 250-watt Bafang rear-hub motor, a top pedal-assisted speed of 20 mph, and reliable disc brakes, the August is no joke. It’ll get you to the top of relatively steep climbs without forcing you out of the saddle, and it feels super stable on the way back down. It has a battery range of 20 miles, but that’s enough to take it where it’s happiest: tootling along at the beach, around town, and through the park.
Federal law defines the limits of a low speed electric bike, equating it to a bicycle, and bypassing the definition of a motor vehicle only “For purposes of motor vehicle safety standards…” which means that the manufacturers of these bicycles don’t have to meet federal equipment requirements, and are instead governed by the manufacturing requirements of the Consumer Product Safety Act. There is no mention of exemption from other federal, state, and local traffic laws, or exemption from the definition of a motor vehicle for other purposes.3 This means the law applies to the manufacturer’s product and sale, avoiding federal safety requirements applying to a motor vehicle such as brake lights, turn signals and braking specifications. The goal of the law was to give businesses a legal framework to define and sell low speed electric bikes without the more stringent Federal classification of a motor vehicle. Ebikes that meet the criteria are considered a “bicycle”, do not meet the definition of a motor vehicle, and will be regulated by the Consumer Product Safety Commission. The law also grants the commission authority to add safety requirements to this product. The Federal law supersedes all state laws that equate bicycles to ebikes where the state law is more stringent (lower limits) on power and speed.
In summary, federal law trumps all States’ laws. That is true with bicycle law, too. States cannot constitutionally pass legislation that reduces or eliminates Federal laws, they can only pass legislation that enacts additional (tighter) restrictions on its people. States can’t define an ebike a bicycle if greater than 750W/20mph, nor can they define an ebike a motor vehicle if less than the Federal Government’s limit of 750 Watts and a top electric-powered speed of 20 MPH.3This is the Federal definition of a low speed electric bike, which equates it to a bicycle.
Electric powered bicycles slower than 20 km/h without pedaling are legally recognized as a non-mechanically operated vehicle in China. According to "TECHNOLOGY WATCH", this should help promote its widespread use. Electric bicycles were banned in some areas of Beijing from August 2002 to January 2006 due to concerns over environmental, safety and city image issues. Beijing has re-allowed use of approved electric bicycles as of January 4, 2006. Some cities in China still ban electric bikes.
If you are a person who enjoys riding a bike casually at a typical bike path speed (10-15mph), and you like the idea of an ebike push up a hill, against the wind or to relieving a sore knee, then your market for a fully legally defined ebike is very broad and your practical use only has a few limitations. Most ebikes will meet your needs and expectation. I would estimate that 85% of the electric bikes on the market are 100% compliant meeting the federal definition. I encourage you to take the plunge and get a good quality ebike and ride more with assist. Do so with the confidence that electric bikes are here to stay. Coexisting with pedestrians and other cyclist will become a normal part of cycling life.
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!
Electric bikes are a green alternative to driving a vehicle. Studies carried out in several towns and cities show that the average car speed in rush hour traffic can dip as low as 18 to 20 mph. Electric bike speed can be as high as 15 mph. With an electric bike, you can reduce pollution, improve fitness, and still arrive at the same time as your car-bound colleagues.
Controllers for brushed motors: Brushed motors are also used in e-bikes but are becoming less common due to their intrinsic lower efficiency. Controllers for brushed motors however are much simpler and cheaper due to the fact they don't require hall sensor feedback and are typically designed to be open-loop controllers. Some controllers can handle multiple voltages.
However, laws and terminology are diverse. Some countries have national regulations but leave the legality of road use for states and provinces to decide. Municipal laws and restrictions add further complications. Systems of classification and nomenclature also vary. Jurisdictions may address "power-assisted bicycle" (Canada) or "power-assisted cycle" (United Kingdom) or "electric pedal-assisted cycles" (European Union) or simply "electric bicycles". Some classify pedelecs as distinct from other bikes using electric power. Thus, the same hardware may be subject to many different classifications and regulations.
Because e-bikes are capable of greater speeds for longer periods of time than standard bikes, you want extra control. Wider tires provide traction and some bump absorption with little penalty. You also want strong brakes to slow you (and all that extra weight) easily. It’s worth looking at the quality of the brakes and investing in bikes with better ones if you can.
The "Dandy horse", also called Draisienne or Laufmaschine, was the first human means of transport to use only two wheels in tandem and was invented by the German Baron Karl von Drais. It is regarded as the modern bicycle's forerunner; Drais introduced it to the public in Mannheim in summer 1817 and in Paris in 1818. Its rider sat astride a wooden frame supported by two in-line wheels and pushed the vehicle along with his or her feet while steering the front wheel.
The days when eMTBs were defined solely by the power of their motors and the size of their batteries are over. Riding performance has become the most important metric. In that pursuit, manufacturers are increasingly developing eMTBs with less power and battery capacity, which in turn handle more like regular mountain bikes. FOCUS started this movement some time ago with its Project-Y concept and later presented the FOCUS RAVEN² PRO, the first production model in a new category of bikes. However this sporty ride only convinced a handful of riders. Meanwhile, Lapierre and BULLS have both announced full-suspension trail bikes featuring the lightweight FAZUA motor for next year. It remains to be seen how many other brands will jump on board this bandwagon – but the rumour mill has already started rumbling. Moreover, it is only a matter of time before the next motor manufacturer will release its own small, lightweight motor.
However, Emu sells a little foldable number if that's your bag. The Emu Crossbar is for town commuters that require a sweet ride that's backed up by solid Shimano Nexus hub gears and Tektro brakes, which are adequate if not the best on the market. Riding is smooth and easy, with the crank moving sensor doing its best to iron out any gaps in power delivery.
There are two main categories when choosing an e-bike: a pre-built electric bike or a custom e-bike conversion. Prefab electric bikes come in a wide variety of setups and styles and are designed specifically as electric bicycles. With unique characteristics and design qualities, most meet the law requirements which limit power and speed. There is also a variety of options to choose from equipped with different design and different motor and battery configurations to suit different riding styles and preferences: cruisers, commuters, mountain bikes and more. Pre-built e-bikes are clean and sleek in design with all of the wiring and electrical components built directly into the bike. For most people, production e-bikes work great and there’s no need for a custom conversion.
The two most common types of hub motors used in electric bicycles are brushed and brushless. Many configurations are available, varying in cost and complexity; direct-drive and geared motor units are both used. An electric power-assist system may be added to almost any pedal cycle using chain drive, belt drive, hub motors or friction drive. BLDC hub motors are a common modern design. The motor is built into the wheel hub itself, and the stator fixed solidly to the axle, and the magnets attached to and rotating with the wheel. The bicycle wheel hub is the motor. The power levels of motors used are influenced by available legal categories and are often, but not always limited to under 750 watts.
Indian law requires that all electric vehicles have ARAI approval. Vehicles with below 250W and speed less than 30 km/h, do not require certification- hence not following full testing process, but needs to get exemption report from ARAI. Whereas more powerful vehicles need to go through a full testing process following CMVR rules. This can take time and cost money but assures safe and reliable design for Electric Vehicles. These regulations are not promulgated by the Regional Transport offices, and riders are not required to obtain a licence to drive, to carry insurance, or to wear a helmet.
Because the power is applied through the chain and sprocket, power is typically limited to around 250–500 watts to protect against fast wear on the drivetrain. An electric mid-drive combined with an internal gear hub at the back hub may require care due to the lack of a clutch mechanism to soften the shock to the gears at the moment of re-engagement. A continuously variable transmission or a fully automatic internal gear hub may reduce the shocks due to the viscosity of oils used for liquid coupling instead of the mechanical couplings of the conventional internal gear hubs.
Under the Guide Section of EBR, Court has written a full article, dedicated to the new classification approach, which was initiated by the BPSA (Bicycle Product Suppliers Association), supported by PeopleForBikes, and then Calbikes. The initiative was meant to be pro-active with ebike legislation, to establish self-imposed, measurable, distinct classes of electric bikes before states start hearing about anecdotal problems and potentially overreact to the technology with wide sweeping limitations.
Can I legally buy/build and ride an ebike that’s faster than 20 mph? Yes you can, but you need to know that the ebike is no longer considered equivalent to a bicycle and is subject to other state vehicular classifications. The definitions for electric bikes spanning 20-30mph, and 1-2 horsepower ranges, will vary from state to state, resulting in a no-man’s-land consensus about limits for motor vehicle definition. The common label for a 20-30mph, 2-wheeled vehicle with active pedals is a Moped. Other MVA labels include motor scooter, motorbike and dirt bike which may have equivalent power and speed performance, but do not have pedals to assist and move the vehicle.
I would advocate you ride legal within the laws of your state. I would also look into some kind of liability rider or umbrella policy with your home owner’s policy, which covers your personal liability and theft. Get your bike registered; wear your helmet, eye protection, whatever is required by state law so that if an accident occurs and you are at fault, there is no legal recourse. Even if you own a 750W/20mph ebike that meets the definition of a bicycle, any at-fault cyclist may still be denied coverage by stingy insurance companies who want to support their clients. Your health insurance will usually cover your medical bills, but the costs of an expensive ebike may be lost.