Some countries require child and/or adult cyclists to wear helmets, as this may protect riders from head trauma. Countries which require adult cyclists to wear helmets include Spain, New Zealand and Australia. Mandatory helmet wearing is one of the most controversial topics in the cycling world, with proponents arguing that it reduces head injuries and thus is an acceptable requirement, while opponents argue that by making cycling seem more dangerous and cumbersome, it reduces cyclist numbers on the streets, creating an overall negative health effect (fewer people cycling for their own health, and the remaining cyclists being more exposed through a reversed safety in numbers effect).
Range is a key consideration with electric 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. The range of an electric bike is usually stated as somewhere between 7 km (uphill on electric power only) to 70 km (minimum assistance) and is highly dependent on whether or not the bike is tested on flat roads or hills. Some manufacturers, such as the Canadian BionX or American E+ (manufactured by Electric Motion Systems), have the option of using regenerative braking, the motor acts as a generator to slow the bike down prior to the brake pads engaging. 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.
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.
Controllers for brushless motors: E-bikes require high initial torque and therefore models that use brushless motors typically have Hall sensor commutation for speed and angle measurement. An electronic controller provides assistance as a function of the sensor inputs, the vehicle speed and the required force. The controllers generally allow input by means of potentiometer or Hall Effect twist grip (or thumb-operated lever throttle), closed-loop speed control for precise speed regulation, protection logic for over-voltage, over-current and thermal protection. Bikes with a pedal assist function typically have a disc on the crank shaft featuring a ring of magnets coupled with a Hall sensor giving rise to a series of pulses, the frequency of which is proportional to pedaling speed. The controller uses pulse width modulation to regulate the power to the motor. Sometimes support is provided for regenerative braking but infrequent braking and the low mass of bicycles limits recovered energy. An implementation is described in an application note for a 200 W, 24 V Brushless DC (BLDC) motor.
As of 2005, where Federal funds have been used in the construction of bicycle or pedestrian paths motor vehicles including electric bicycles (here defined as having a motor weighing less than Template:Convert) are not permitted unless State or Local regulations permit . This was known as the Transportation Equity Act for the 21st Century (TEA-21), or Public Law 105-178, or by its 2003 re-authorization which expired in 2005 the Safe, Accountable, Flexible, Efficient Transportation Equity Act (SAFETEA-LU).
Like most electric bikes, the Rad Wagon is also fairly heavy, weighing 72 pounds. The last drawback is that it comes in only one frame size (which I imagine helps to keep costs lower) that fits rider heights between 5 foot 2 inches and 6 foot 2 inches. My 6 foot 4 husband, however, can ride the bike just fine, so there’s some wiggle room to this range.
Even the humble bicycle hasn't escaped the clutches of modern technology. A whole herd of new e-bikes with electric motors are taking to our cities' streets. Adding a motor to a standard cycle does ramp up the price significantly, but it takes much of the effort out of cycling, making your commute to the office a sweat-free experience and allowing you to sit back and enjoy your suburban cruise.
It appears Tennessee has not passed any legislation that applies to electric bicycles. Some people think the laws pertaining to a Motorized Bicycle should be used for an electric bicycle. However, a Motorized bicycle would be a gasoline powered device per state law as it is defined as "means a vehicle with two (2) or three (3) wheels, an automatic transmission, and a motor with a cylinder capacity not exceeding fifty cubic centimeters (50cc) which produces no more than two (2) brake horsepower and is capable of propelling the vehicle at a maximum design speed of no more than thirty miles per hour (30 mph) on level ground." 
The European Committee for Standardization (CEN) also has a specific Technical Committee, TC333, that defines European standards for cycles. Their mandate states that EN cycle standards shall harmonize with ISO standards. Some CEN cycle standards were developed before ISO published their standards, leading to strong European influences in this area. European cycle standards tend to describe minimum safety requirements, while ISO standards have historically harmonized parts geometry.
In addition the specific wording of the law may or may not prohibit the use of a "mid-drive" or "crank-drive" motor set-up where the motor drives the rear wheel of the bicycle through the existing chain drive of a bicycle that has multiple gears depending on several points of interpretation of the law. Specifically the interpretation of the wording, "does not require clutching or shifting by the operator after the drive system is engaged". A "mid-drive" or "crank-drive" motor set-up on an electric bicycle does indeed allow the operator to change gears in the power drive system between the motor and the rear wheel of the bicycle. Whether or not such a mechanism which allows the operator to change gears satisfies the wording that requires the operator to change gears is a matter of legal interpretation by the courts. Just as "shall issue" and "may issue" (as in laws governing the issuing licenses) in application of the law have two different meanings (in the first case if you meet the requirements they have to give you the license and in the second they don't have to if they decide not to even if you meet the requirements for the license) whether or not "does not require shifting" outlaws electric bicycles where shifting is possible but is not necessarily required is a matter of interpretation. Thus the legality of electric bicycles equipped with a "mid-drive" or "crank-drive" motor set-up in the U.S. state of Montana is not clearly defined.
In the year 1885, a British man named J.K. Stanley introduced what can fairly be described as the first modern bicycle. His Rover bike had wheels of equal size in the front and back and used a chain connecting the pedals and the rear wheel as a propulsion system. It was often marketed as a safety bike in contrast with the unstable Penny Farthing, and was a smashing success. The company went on to develop motorcycles and automobiles, remaining in business until the year 2005.
Not all e-bikes take the form of conventional push-bikes with an incorporated motor, such as the Cytronex bicycles which use a small battery disguised as a water bottle. Some are designed to take the appearance of low capacity motorcycles, but smaller in size and consisting of an electric motor rather than a petrol engine. For example, the Sakura e-bike incorporates a 200 W motor found on standard e-bikes, but also includes plastic cladding, front and rear lights, and a speedometer. It is styled as a modern moped, and is often mistaken for one.
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.
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.
Some e-bikes operate in pedal-assist only, others have a throttle, and some have both. Generally, pedal-assist only bikes will provide multiple power settings to choose from to help customize your ride, while bikes with both throttle and pedal-assist will have limited pedal-assist options. With these bikes, the throttle provides full control (when needed) while pedal assist is just a secondary option, great on straightaways or open road.
E-bike usage worldwide has experienced rapid growth since 1998. In 2016 there were 210 million electric bikes worldwide used daily. It is estimated that there were roughly 120 million e-bikes in China in early 2010, and sales are expanding rapidly in India, the United States of America, Germany, the Netherlands, and Switzerland. A total of 700,000 e-bikes were sold in Europe in 2010, up from 200,000 in 2007 and 500,000 units in 2009.
Electric motor assisted bicycles have been banned in the State of New York and are not permitted for on-road use. It appears the only known allowance of an electric bicycle is if it is an electric powered moped, at this time. There is a proposed bill to allow ebikes. As of May 2009, Bill A2393("Defines the term electric assisted bicycle") has been passed in the NY State Assembly and its corresponding Bill S4014, sponsored by Senator Thomas Morahan, is before the NY State Senate.
Gearless (Direct-Drive) Hub Motors – Some conversion kits (and bikes) use gearless, direct-drive motors. On this type of motor, the axle that passes through the center of the motor is actually the axle of the motor itself, with the copper windings fixed to the axle. The magnets are mounted to the outer shell of the hub motor. When electricity is applied to the stator a magnetic field is induced that causes the magnets to move. This in turn makes the whole shell of the motor turn and propels the e-bike forward. Even though corrosion will eventually have an impact, this type of motor should last for years since there’s no gearing and no contact between moving parts. They’re also capable of higher top speeds. But since there’s no gears, they have less torque and it requires more power to get the motor up to speed. Most direct-drive hub motors are 350w-500w and reach speeds of 18-25 mph. But more powerful motors can reach speeds of 35+ mph.
Electric-assisted bicycle operators must follow the same traffic laws as operators of motor vehicles (except those that by their nature would not be relevant). The bicycles may be operated two abreast. Operators must generally ride as close as is practical to the right-hand side of the road (exceptions include when overtaking another vehicle, preparing for a left turn, and to avoid unsafe conditions). The bicycle must be ridden within a single lane. Travel on the shoulder of a road must be in the same direction as the direction of adjacent traffic.
Some US companies, notably in the tech sector, are developing both innovative cycle designs and cycle-friendliness in the workplace. Foursquare, whose CEO Dennis Crowley "pedaled to pitch meetings ... [when he] was raising money from venture capitalists" on a two-wheeler, chose a new location for its New York headquarters "based on where biking would be easy". Parking in the office was also integral to HQ planning. Mitchell Moss, who runs the Rudin Center for Transportation Policy & Management at New York University, said in 2012: "Biking has become the mode of choice for the educated high tech worker".