The recommendation depends a lot on what you plan to use the bike for and how you plan to ride. That said, I would recommend at least a 750 (if not 1,000) watt motor, and, if you want reasonable range, 48 or 52v cells with a minimum rating of 19ah. For shorter rides, you can use a smaller battery. Multiply battery voltage by amp hour rating to get battery watt hours. Divide the watt hours by the motors power rating to get a general idea of how many hours of heavy use you might get. I’d also recommend a mid drive as opposed to a hub drive, or to find a hub drive wheel rated to take your and the bicycle's combined weight.
Whether the terrain is flat or hilly impacts the distance you can travel, as does the weight of the bike, your own weight, the gearing available on the bike, and how much juice you give it. We suggest that a distance of 10 to 20 miles is a realistic expectation. Of course, if you're prepared to do at least some pedaling, you can extend that dramatically.
An electric bike (also called e-bike, power-assist bike, pedelec…) is a fairly conventional bike combined with a battery and motor that helps out when you are pedaling to make it easier to get uphill or completely takes over driving and allows you to cruise along. Top quality electric bikes, along with electric scooters, are revolutionizing the bicycle industry. Not only is riding an e-bike simple and easy, but a rider can significantly extend their range with minimal cost or effort.
In the early 1860s, Frenchmen Pierre Michaux and Pierre Lallement took bicycle design in a new direction by adding a mechanical crank drive with pedals on an enlarged front wheel (the velocipede). This was the first in mass production. Another French inventor named Douglas Grasso had a failed prototype of Pierre Lallement's bicycle several years earlier. Several inventions followed using rear-wheel drive, the best known being the rod-driven velocipede by Scotsman Thomas McCall in 1869. In that same year, bicycle wheels with wire spokes were patented by Eugène Meyer of Paris.[22] The French vélocipède, made of iron and wood, developed into the "penny-farthing" (historically known as an "ordinary bicycle", a retronym, since there was then no other kind).[23] It featured a tubular steel frame on which were mounted wire-spoked wheels with solid rubber tires. These bicycles were difficult to ride due to their high seat and poor weight distribution. In 1868 Rowley Turner, a sales agent of the Coventry Sewing Machine Company (which soon became the Coventry Machinists Company), brought a Michaux cycle to Coventry, England. His uncle, Josiah Turner, and business partner James Starley, used this as a basis for the 'Coventry Model' in what became Britain's first cycle factory.[24]
E-bikes are zero-emissions vehicles, as they emit no combustion by-products. However, the environmental effects of electricity generation and power distribution and of manufacturing and disposing of (limited life) high storage density batteries must be taken into account. Even with these issues considered, e-bikes are claimed to have a significantly lower environmental impact than conventional automobiles, and are generally seen as environmentally desirable in an urban environment.[65]
Thanks for your excellent article. I’ve been riding ebike for about 16 years. My first electric bike was a Meridian pedal assist bike. I just up graded to a new bike. I’m 73, so I wanted a pedal assist bike that had a throttle. I researched for several months and bought what I think is the best bike for the money. It’s a Rad Rover 2017 fat bike. It has a 750 watt mother with a 48 volt 11.6 amp battery. It’s a fantastic bike, that is a lot of fun to ride. You might want to check it out and add it to your list of bikes. Rad Rover also make a city commuter bike, a cargo bike and a folding bike. You can’t beat their price for a quality bike. Thanks again for both of your articles. They were very informative.
This dexterous electric dirt bike is recommended for anyone over the age of 14. It’s fitted with double suspension and big tyres to help you tackle tough terrain. You also get a good selection of gears, that gives you optimal control. The Razor can go as fast as 15 mph on average, and comes with an excellent braking system. The aesthetics are on point, and the racer look is sure to impress. Don’t forget your helmet!
If you are an experienced rider this is actually annoying as hell. Personally, I tend to leave whatever I'm riding in a high gear all the time, because my body is like a powerful machine, and I found the way it slowed my escape from the lights quite disconcerting. For beginners, it could be useful, but it's worth remembering that the whole point of e-bikes is that the motor helps you along anyway, so I do really question the usefulness of this.

Eight provinces of Canada allow electric power assisted bicycles. In all eight provinces, e-bikes are limited to 500 W output, and cannot travel faster than 32 km/h (20 mph) on motor power alone on level ground.[12] In Alberta prior to July 1, 2009, the limits were 750 W and 35 km/h (22 mph), but presently match federal legislation.[13] Age restrictions vary in Canada. All require an approved helmet. Regulations may or may not require an interlock to prevent use of power when the rider is not pedaling. Some versions (e.g., if capable of operating without pedaling) of e-bikes require drivers' licenses in some provinces and have age restrictions. Vehicle licenses and liability insurance are not required. Generally, they are considered vehicles (like motorcycles and pedal cycles), so are subject to the same rules of the road as regular bicycles. In some cases, regulatory requirements have been complicated by lobbying in respect of the Segway PT.
Awesome little machine. My wife loves it. She gets so many people asking her where she got it and that they want one too. I have an 6 speed/ electric bike but she is not comfortable riding it or any bike for that matter but she’s totally comfortable and confident when she rides the swag. Great product. Exceptional quality and cool looking too. You can’t go wrong with this machine for your wife or daughter or whomever wants to ride but doesn’t want anything bulky or to heavy.

A motorized bicycle shall not be operated by any person under sixteen years of age, nor at a speed in excess of twenty-five miles per hour, upon any public highway, private way laid out under authority of statute, way dedicated to public use, or way under the control of park commissioners or body having like powers, within the commonwealth.[99] A motorized bicycle shall not be operated on any way by any person not possessing a valid driver's license or learner's permit. Every person operating a motorized bicycle upon a way shall have the right to use all public ways in the commonwealth except limited access or express state highways where signs specifically prohibiting bicycles have been posted, and shall be subject to the traffic laws and regulations of the commonwealth and the regulations contained in this section, except that the motorized bicycle operator may keep to the right when passing a motor vehicle which is moving in the travel lane of the way, and the motorized bicycle operator shall signal by either hand his intention to stop or turn. Motorized bicycles may be operated on bicycle lanes adjacent to the various ways, but shall be excluded from off-street recreational bicycle paths. Every person operating a motorized bicycle or riding as a passenger on a motorized bicycle shall wear protective headgear conforming with such minimum standards of construction and performance as the registrar may prescribe, and no person operating a motorized bicycle shall permit any other person to ride a passenger on such motorized bicycle unless such passenger is wearing such protective headgear.

Both the Stromer and the Stoeckli are very nice looking designs and easy to handle. Reliability for both does not seem to be up to Swiss standards, e.g. some of the 2012 Stöcklis seem to have bad contacts. However, as of 2013, most of these problems should be fixed. The Cube got criticized for its battery/saddle system, but this has probably been fixed in more recent edition and it has less "punch" then the other's since the motor is smaller (324W?). I don't know about the BH Neo Nitro. Given the relatively low price of the BH Nitro, it may be the best buy in this category if you plan to cover smaller distances (the battery is limited to 9Ah, and Spain's industry does need some help ;) Anyhow, all of these models come with a variety of motors and country-specific modifications. E.g. in France, the BH Nitro comes with a 350W motor and is electronically limited to 25km/h, whereas in Switzerland you either can get a 500W - 45 km/h version or a 250W? - 25km/h version.
For those who missed seeing it live, we've also uploaded a youtube video of our live demonstration of a regular bike being converted over to electric assist. We hope that this helps demystify the process for some considering their first kit purchase. It was a fun opportunity as the owner of the bike was at the show and could ride it away the next day.

Most consumers want an e-bike that will accommodate its motor without being too cumbersome and will remain stable in spite of its electronic components. Some consumers want only the most basic of e-bike features, including lights, a cargo rack/basket, and a water bottle holder. Others are focused more heavily on safety features, such as brake type. And still others are concerned with convenience and portability.
Since cyclists' legs are most efficient over a narrow range of pedaling speeds, or cadence, a variable gear ratio helps a cyclist to maintain an optimum pedalling speed while covering varied terrain. Some, mainly utility, bicycles use hub gears with between 3 and 14 ratios, but most use the generally more efficient dérailleur system, by which the chain is moved between different cogs called chainrings and sprockets in order to select a ratio. A dérailleur system normally has two dérailleurs, or mechs, one at the front to select the chainring and another at the back to select the sprocket. Most bikes have two or three chainrings, and from 5 to 11 sprockets on the back, with the number of theoretical gears calculated by multiplying front by back. In reality, many gears overlap or require the chain to run diagonally, so the number of usable gears is fewer.
The Shift S1 isn’t going to blow anyone away with amazing performance, but it is peppy enough to have a lot of fun on. And if you mostly travel by rideshares like Uber or scootershares like Bird, you can probably pay for the S1 after just a few months of cutting out app-based transportation. It’s hard to ask for too much more from such an inexpensive e-bike.
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") 

At 42 pounds for a size medium frame (exceptionally light for an urban e-bike), this step-through model’s silent, mid-drive Bosch Active Line motor provides pedal assist up to 20 mph. And its 400Wh battery lasts a claimed 30 to a whopping 110 miles, depending on mode, speed, terrain, rider weight, cargo—all the usual stuff. With 26-inch wheels, 2-inch tires, round aluminum tubes, a swept-back handlebar, Shimano Sora 9-speed components, and an 11-32 cassette, the Parkway looks like an everyday, non-motorized city bike at first glance. But with an array of Bosch e-components—motor, battery, and Purion display—it has the zip to take you farther faster.
As long as the electric bicycle meets three criteria it is considered a low-speed electric bicycle, or simply a "bicycle." Three criteria: must travel less than 20 mph on flat ground without pedaling, must have functional pedals and must have less than a 750 watt motor. This is the same criteria as Federal Public Law 107-319. I checked my facts with the law office of Spohn, Spohn & Zeigler at 144 East Center Street, Marion, OH 43302 on August 21, 2009. A low-speed electric bicycle does not require registration, insurance, license plates (tags), or a driver's license. The rules of an electric bicycle are the same as a traditional bicycle. There is some confusion caused by Ohio interchanging the word Moped with "motorized bicycle." If a dealer sells you a bike that follows the guidelines of Federal Public Law 107-319, then you have a bicycle. If the bike has no pedals or has a higher wattage motor than 750 watts or can travel faster than 20mph you have a moped or scooter; Ohio requires tags and registration for mopeds and scooters.

As with all these bikes, the assisted speed is capped at 15mph, but unlike some of them, the Gtech eBike City or its identical (spec-wise) sibling the eBike Sport (this just has a standard frame rather than a step-through one) is light and agile enough for you to be able pedal harder without feeling like the weight is fighting you back down to 15mph. You can even, at a push, use it without the motor on flatter roads.
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.

How do the State Laws relate to the 2001 Federal Law? This is a difficult question to answer and know how they apply to you individually. From the Federal Law, one would hope that your purchased ebike is simply classified as a bicycle, with all the rights and privileges allotted to a normal cyclist. However, State Laws are confusing because they may be more restrictive in parts and add other requirements. About 30 U.S. states still have confusing regulations around them. Either the bikes are technically classified as mopeds or motor vehicles, or they have equipment, licensing or registration requirements that cause problems for riders. Thanks to the People-For-Bikes/Bicycle Product Suppliers Association (BPSA) partnership with local advocacy groups, they have been able to make the case for streamlining state regulations so that e-bikes are essentially treated like regular bicycles.4
Great question… a real world situation from someone doing their best to follow the law but also be realistic about time/distance. What follows is my opinion on the matter based on lots of electric bike riding experience, this is not legal advice. You can probably ride with electric assist across the dirt way with no issues and avoid any negative response that might arise as long as you’re polite to other cyclists and pedestrians and pedal along without going too fast. If someone called you out about it you could easily hop off, walk your bike and explain that you use the assist to help make your commute possible or possibly, like me, you have a knee injury and it’s difficult to pedal through softer terrain like gravel. Another different approach might be to shut the bike off completely before entering the gravel section, you could even take the battery off and put it in a backpack or as mentioned earlier… just walk the bike. Imagine if you had a motorized dirt bike and were just pushing it along a sidewalk… this kind of vehicle definitely is not allowed on sidewalks or most gravel paths like the one you’re describing but if you were escorting it carefully, you’d be honoring the spirit of the law and if an officer or pedestrian jumped out and started questioning you about your “motorized vehicle” it is my feeling that a genuine explanation and apology or request for guidance would go very well. I personally have never had issues riding electric bikes in part because I am thoughtful about how I use them. I do occasionally switch them off and sometimes I get off and walk. I have asked police in many cities across the US what they thought about ebikes and in every case I have received positive interest and support with guidance to ride safe with a helmet and follow traffic laws in the street. I hope this helps and I wish you well, it’s nice that you care enough to ask and I hope you’re treated well by others out on the road. The flip side of this response is that I have been harassed, yelled at and even swerved at by automobiles when riding bicycles and electric bikes. This usually happens in the evening after work lets out when traffic is heavy and I’m riding on the shoulder or in the street (where marked to do so) and I believe it has to do with territory, testosterone and socio-economic standing more so than laws or anything like that.

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. 

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.
Further innovations increased comfort and ushered in a second bicycle craze, the 1890s Golden Age of Bicycles. In 1888, Scotsman John Boyd Dunlop introduced the first practical pneumatic tire, which soon became universal. Willie Hume demonstrated the supremacy of Dunlop's tyres in 1889, winning the tyre's first-ever races in Ireland and then England.[28][29] Soon after, the rear freewheel was developed, enabling the rider to coast. This refinement led to the 1890s invention[30] of coaster brakes. Dérailleur gears and hand-operated Bowden cable-pull brakes were also developed during these years, but were only slowly adopted by casual riders.

The Bulls Cross E8 Step-Thru is an urban bike—a bicycle often used as a primary mode of transportation for those who choose not to own a car. Priced at $3,099, it's solid and durable. The aluminum frame comes in three sizes (45cm, 50cm, and 53cm; I tested the latter). It's got an eight-speed Shimano shifter and a Shimano Deore CS-HG50 cassette. Shimano is a small change for me, as my XO2 uses the SRAM Rival Double Tap shifter, and I really like the action on that. It's got a front suspension with 63mm of travel for a smoother ride, along with Shimano hydraulic disc brakes. Cable runs are all internal, making for a cleaner-looking profile. Rack, fenders, and a headlight all come standard.
In the theoretical electric bike we considered up above, we had the dynamo/motor driving the back wheel directly, simply by pressing on the tire. Most electric bikes work a different way. They have compact electric motors built into the hub of the back or front wheel (or mounted in the center of the bike and connected to the pedal sprocket). Take a look at the hub of an electric bike and probably you'll see it's much fatter and bulkier than on a normal bike. You can read more about how these motors work in our main article about hub motors.

Simple, convenient, cheap, and economical—bicycles are one of the world's favorite forms of transportation. But they're not for everyone. They can be hard to pedal up and down hills or with heavy loads, and elderly or disabled people may find them impossible to manage. In the last few years, a new generation of electric bicycles has begun to revolutionize our idea of environmentally friendly transportation. These new cycles have all the convenience of cars with all the simple economy of ordinary cycles. Let's take a closer look at how they work.