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]
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.
Electric-assisted bicycles are treated as human-powered bicycles, while bicycles capable of propulsion by electric power alone face additional registration and regulatory requirements as mopeds. Requirements include electric power generation by a motor that cannot be easily modified, along with a power assist mechanism that operates safely and smoothly. In December 2008, The assist ratio was updated as follow:
On February 4, 2014, SB997 was introduced by Senator Matt Smith, which seeks to amend PA Vehicle Code to include "Pedalcycle with Electric Assist". In a memo addressed to all senate members, Smith said the definition shall include "bicycles equipped with an electric motor not exceeding 750 watts, weighing not more than 100 pounds, are capable of a maximum speed of not more than 20 mph, and have operable pedals."[128][129]
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.

Electrically-assisted cycles are usually classified as either pedelecs or e-bikes. Under European Union regulations adopted in the UK in June 2003, only power-assisted cycles meeting the pedelec classification are considered to be pedal cycles. The maximum power allowed in the European Union for (pedelec) electric bicycles is 250 W, with a maximum assisted speed of 25 km/h.[15]. To meet the pedelec specification the electric motor must be activated by the rider's pedalling effort and the power must cut out completely whenever the rider stops pedalling. Control of the motor by pedalling is often the key difference between a pedelec and e-bike.
The environmental effects involved in recharging the batteries can of course be reduced. The small size of the battery pack on an e-bike, relative to the larger pack used in an electric car, makes them very good candidates for charging via solar power or other renewable energy resources. Sanyo capitalized on this benefit when it set up "solar parking lots", in which e-bike riders can charge their vehicles while parked under photovoltaic panels.[66]
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.[43]
Your local state may have very definite rules as to what is an e-bike, what is a moped, and what is a motorcycle. While ebikes enthusiast don’t want the motor vehicle label, it is certain that each state will define some power level and speed where that classification will apply. Your best source of information is to go directly to your state motor vehicle department website, and get a copy of the your local state vehicle codes, with NO EDITING. Only recently updated official state vehicle codes will contain all the latest changes to the laws.1 For a link to your state MVA, look here:2

Oregon Law (ORS 801.258]) defines an electric assisted bicycle as an electric motor-driven vehicle equipped with operable pedals, a seat or saddle for the rider, no more than three wheels in contact during travel. In addition, the vehicle must be equipped with an electric motor that is capable of applying a power output of no greater than 1,000 watts, and that is incapable of propelling the vehicle at a speed greater than 20 miles per hour on level ground.[124]
Ebike definition in Colorado follows the HR 727 National Law: Template:Convert e-power and Template:Convert max, 2 or 3 wheels, pedals that work. Legal low powered Ebikes are allowed on roads and bike lanes unless the city or county has passed laws to the contrary (Boulder city bans ebikes over 400W from bike lanes and all ebikes from bike paths) -none -(except Boulder city) have to date. Bicycles and Ebikes are disallowed on certain high speed highways and all Interstates unless signed as "Allowed" in certain rural Interstate stretches where the Interstate is the ONLY means of travel. [35] Unless the locality has specifically passed laws making ebikes illegal on sidewalks or trails, Ebikes are legal. However most business and shopping districts do not allow riding bikes or ebikes on sidewalks. Boulder and a few other cities specifically dis-allow ebikes on their trail systems through legal statute.
While falling gas prices have temporarily halted years of gains in the number of bicycle commuters, more and more of us are using the bicycle to get around. It’s economical, provides good exercise, and is much cheaper than owning a car. But unless you’re in really good shape, you aren’t going to get very far. Enter the electric bike: a glorious new contraption allows us to get around without having to worry about arriving at our destinations a sweaty mess.
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. 

In most jurisdictions, bicycles must have functioning front and rear lights when ridden after dark. As some generator or dynamo-driven lamps only operate while moving, rear reflectors are frequently also mandatory. Since a moving bicycle makes little noise, some countries insist that bicycles have a warning bell for use when approaching pedestrians, equestrians, and other cyclists, though sometimes a car horn can be used when a 12 volt battery is available.[citation needed]
Besides voltage, batteries are rated by amp hours (AH). Although voltage seems to get the most attention, the amp hour rating of the battery is just as important. It is the measure of a battery’s capacity and provides a good indication of the range you can expect from an electric bike. Although lots of factors come into play in determining range (ie: rider weight, terrain, input, efficiency, etc.), a good rule of thumb is range is equal to AH. So under normal conditions, an average rider can expect 10 miles out of a 10AH battery (with no pedaling). With rider input, this number can be dramatically increased, so most 10AH batteries are rated “up to 20 miles” by the manufacturer which assumes pedaling. On pedal-assist bikes (which require pedaling), the range ratings are much higher because the rider is constantly assisting the motor and reducing the current draw.
E-bikes can boost bike usage, offer health benefits and use “an order of magnitude less carbon dioxide than a car traveling the same distance,” according to a 2016 research review published in the journal Transport Reviews.  In fact, access to an e-bike increased cycling trips and distances traveled – and nearly doubled the bike as a mode of transportation, observed one Norwegian study.
Maintenance of adequate tire inflation is the most frequent and troublesome concern for cyclists and many means and methods are employed to preserve pneumatic integrity. Thicker tires, thicker tubes, tire liners (of a number of rather impenetrable devices installed between the tire and tube), liquid sealing compounds squeezed into the tube, and automotive-style patch kits are all used to reliably contain the typical tire pressures of 40 to 60 pounds per square inch that are required for bicycle operation. Thin, light bicycle tires are particularly vulnerable to penetration and subsequent deflation caused by goat's heads and other burs, colloquially known as stickers. Inflation of bicycle tires to pressures higher than typical for automotive use requires special pumps. The complexity of bicycle tire maintenance and repair may cause many to not consider the bicycle for transport or leisure.

Federal law in the United States states that an electric bicycle must have a top speed under 20 mph and a motor which produces less than 750 watts/1 hp. They are not considered motor vehicles by the federal government and are subject to the same consumer safety laws as unassisted bicycles.[11] Their legality on public roads is under state jurisdiction, and varies. See the main Electric bicycle laws article for details on the law in individual states.
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.
The Surly Big Easy is the Cadillac of the bike lane. The company’s new longtail e-cargo bike exudes a “they don’t make ’em like this anymore” stature, thanks to a beefed-up chromoly steel frame rolling on tough 26x2.5-inch tires. And because it’s a class 1 e-bike, you can actually ride it in the bike lane, too. The 7-foot-long, 67-pound bike won’t play well with your third-floor walk-up, so it’s best to think of it as a car supplement or replacement—that’s what Surly intended, anyway, as evidenced by the $5,000 price tag. However, if you’re ready to commit to the cargo bike life, you’ll struggle to find a stronger platform for achieving bike commuter nirvana.

First off we want to apologize for the longer than normal response time and email backlog as much of our team was busy both in the preparation and attendance at the Taipei Cycle Show this past week. We'll be working hard to catch up on that in the coming days and thank your patience and understanding. To all the dealers, vendors, manufacturers, component partners, and general industry friends we met at the show, what a great time and we look forward to exciting pursuits ahead. 

Nevada Electric Bicycle (NRS 482.0287) Bicycle 20 (motor only on the flat with 170LB rider, undefined if pedal assist is allowed to go faster) 750W (it is undefined as to whether this is input or output power, but in the USA, motors are rated on output power at the shaft) No none (use caution here because of "reckless endangerment" laws) no (not a "motor vehicle")
To operate the bike, you have to pedal for a second or so before the thumb throttle becomes active. This is often a cost and energy-saving measure designed into electric bicycles and scooters. Being able to start the motor from rest requires extra sensors and higher battery power. Starting the motor while it is in motion removes the need to install extra sensors in the motor (and thus removes one more possible failure or maintenance issue) and also eeks more range out of the battery by putting the energy intensive initial startup responsibility solely on the rider.

In a friction drive motor, a small, solid wheel rotates against the side of the tire in order to drive it. The first motorcycles used the same concept, with a motor mounted above the front wheel. The problem is that the drive rubs at the side of the tire. It's inefficient, and it quickly wears the sidewall away. Tires need to be replaced every couple hundred miles. For this reason, you'll seldom see electric bikes with this type of drive anymore.

Electric-assisted bicycles, also referred to as "e-bikes," are a subset of bicycles that are equipped with a small attached motor. To be classified as an "electric-assisted bicycle" in Minnesota, the bicycle must have a saddle and operable pedals, two or three wheels, and an electric motor of up to 1,000 watts, as well as meet certain federal motor vehicle safety standards. The motor must disengage during braking and have a maximum speed of 20 miles per hour (whether assisted by human power or not). Minn. Stat. §169.011, subd. 27.
Ride1Up 500 series City is a high quality, classy and stylish electric city bike with great features at a really great price. It is designed for the everyday long-distance rider and it features very nice frame geometry that promotes a comfortable upright riding position. Swept-back cafe style handlebars also provide better comfort over longer distances. You can choose between two throttle options – a twist or a thumb throttle, and there are also 3 levels of pedal-assist, or 9 levels if you get an optional LCD screen. Other features include an integrated LED headlight, removable battery with two keys, and heavy duty kickstand. Also we have to commend the amazing customer service, as the guys that are behind this brand are very passionate about what they do, and really motivated to change the way we get around our communities, by providing high-quality bikes at an unbeatable price.
E-bikes use rechargeable batteries, electric motors and some form of control. Battery systems in use include sealed lead-acid (SLA), nickel-cadmium (NiCad), nickel-metal hydride (NiMH) or lithium-ion polymer (Li-ion). Batteries vary according to the voltage, total charge capacity (amp hours), weight, the number of charging cycles before performance degrades, and ability to handle over-voltage charging conditions. The energy costs of operating e-bikes are small, but there can be considerable battery replacement costs. The lifespan of a battery pack varies depending on the type of usage. Shallow discharge/recharge cycles will help extend the overall battery life.
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.