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]

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.

The battery is the pedelec’s power source. It supplies the motor with the electrical energy that is required to provide power assistance when cycling. So it is hardly surprising that there is frequent discussion and “talking shop” about the eBike’s battery in particular. What is the difference between batteries? How far can you go on a fully charged battery? What do you have to remember about storage? Thomas Raica, head of technical customer application, here provides information and advice.


What an experience. I really had no idea what to expect when I first got on. The ride was smooth, and the assisting function was excellent and seamless. It is not like a motorcycle, it is just like a bike with some extra help. I felt completely safe on this bike, as well as comfortable in the seat. Especially in San Francisco with all the hills, going up the ramp felt like I was moving on a flat surface still. For commuters who might be worried about having to change clothes during an arduous commute in on their bike, fear not. This bike makes everything easy, and simple enough that you could ride to work in your work clothes and not fear getting too hot and sweaty. For those who have switched to the bike to decrease their impact on the environment, this bike is a must. Get there fast,
The bicycle is extraordinarily efficient in both biological and mechanical terms. The bicycle is the most efficient human-powered means of transportation in terms of energy a person must expend to travel a given distance.[38] From a mechanical viewpoint, up to 99% of the energy delivered by the rider into the pedals is transmitted to the wheels, although the use of gearing mechanisms may reduce this by 10–15%.[39][40] In terms of the ratio of cargo weight a bicycle can carry to total weight, it is also an efficient means of cargo transportation.
This is one of the most incredible eBikes on the market today! The Riese and Muller SuperCharger Rohloff GX is one of our most popular models and we know they are being put through thousands of miles across the Southeast. From the coastal areas to the Appalachian mountains, we have customers buying and riding these highly engineered eBikes. These eBikes …
There are no ADRs applicable to AA or AB category vehicles. There are ADRs for lighting, braking, noise, controls and dimensions for LA category vehicles, mostly referencing the equivalent UN ECE Regulations. An approval is required to supply to the market any road vehicle to which ADRs apply and an import approval is required to import any road vehicle into Australia.[5]
The Tidalforce Electric Bicycle was an electric bicycle manufactured by Wavecrest Labs from 2003 until the company went out of business in 2006. All models of Wavecrest Tidalforce electric bikes have a 36 volt electric hub motor built into the rear wheel hub and a 36 volt battery pack built into the front wheel hub. Wavecrest Labs manufactured three models of Tidalforce bikes: The Wavecrest Tidalforce M-750, the S-750 Traditional hard tail mountain bike and the iO-750 Cruiser. Any of the three bikes with an X suffix denotes that the motor is a 1000 watt motor without a set speed restriction as compared to the speed limited 750 watt version.

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 Footloose has no chain, however -- it's entirely electrically driven. It takes very little effort to get to your destination, meaning you arrive at work without having broken a sweat. The downside is that when you run out of power, you're not going anywhere. And pedalling from a standstill, waiting for the motor to kick in, is an odd sensation that takes some getting used to.

Photo: This typical electric bicycle, a Sanyo Eneloop (now discontinued), had a range of about 30–55 km (17–35 miles) and a top speed of around 24 km/h (15 mph). Note the 250-watt hub motor on the front wheel and the 5.7Ah lithium-ion battery pack (black, marked "Sanyo," just in front of the back wheel). Picture by kind permission and courtesy of Richard Masoner, originally published on Flickr under a Creative Commons (CC BY-SA 2.0) licence.
"Bicycle" means either of the following: (1) A device having two wheels and having at least one saddle or seat for the use of a rider which is propelled by human power. (2) A device having two or three wheels with fully operable pedals and an electric motor of less than 750 watts (one horsepower), whose maximum speed on a paved level surface, when powered solely by such a motor while ridden, is less than 20 miles per hour.
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.

The Consumer Product Safety Commission(CPSC) stipulates that commercially manufactured low-speed electric bicycles, or tricycles, must have fully operable pedals, an electric motor not exceeding 750W of power and a top motor-powered speed not in excess of 20 miles per hour (32 km/h).[22] An electric bike remaining within these specifications will be regarded simply as a bicycle for purposes of safety standards. This supersedes any state law that is more stringent, but only regarding safety equipment required on electric bicycles and the standard of manufacture they must meet.[23]. The legislation enacting this amendment to the CPSC is also known as HR 727[24].
In a parallel hybrid motorized bicycle, such as the aforementioned 1897 invention by Hosea W. Libbey, human and motor inputs are mechanically coupled either in the bottom bracket, the rear wheel, or the front wheel, whereas in a (mechanical) series hybrid cycle, the human and motor inputs are coupled through differential gearing. In an (electronic) series hybrid cycle, human power is converted into electricity and is fed directly into the motor and mostly additional electricity is supplied from a battery.

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.

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]


If you are a regular bicyclist who wants to add some excitement to your rides or wants some help with those hills, a full sized electric bike is the way to go. If you are considering a bike as a means of transportation more than an outlet for amusement, then a smaller, folding electric bike is the convenient choice. In each category, consider the speed and range you want, as these factors impact price.
The Footloose has no chain, however -- it's entirely electrically driven. It takes very little effort to get to your destination, meaning you arrive at work without having broken a sweat. The downside is that when you run out of power, you're not going anywhere. And pedalling from a standstill, waiting for the motor to kick in, is an odd sensation that takes some getting used to.
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.
To help the rider find the perfect fit, the stem is adjustable. The bike also boasts dynamo powered lights alongside hydraulic disc brakes. The bike will suit riders from 4 ft 10 to 6 ft 5, and also integrates with a child seat. The total weight is 22.5kg, making it admittedly a fairly hefty folder – but that’s fairly uniform across electric versions.

We bought 2 of these to go along with our AW 26"x1.75" Front Wheel Electric Bicycle Motor Kits and they work perfectly! The batteries that came with and were recommended by the wheel manufacturer were "clunky", had to be mounted in hanging bags and just didn't work well. These Li-ion Battery with Battery Holders are sleek, fit our Beach Cruisers perfectly, give us a rack to carry our "beach stuff" and one of the best features is how easy they are to charge! They lock in place when we are out and about, but I can unlock them, slide them both out and take them into the RV for charging when we return. Very happy with these and would recommend to anyone looking to convert their current bike into e-bikes!
It should be noted that the definition as written does not define the power of the motor in Watts as is conventionally done for electric bicycles but rather in brake horsepower. Thus for an electric bicycle, motor kit, or electric bicycle motor that is not rated by the manufacture in brake horsepower but rather in Watts a conversion must be made in the units a conversion which is not given in the code of the law and thus the court will have to consider a factor of conversion that is not directly encoded in the law. Industry standard conversion for Watts to horsepower for electric motors is 1 horsepower = 746 watts.[105] Acceptance of that conversion factor from industry, however, as interpretation of the law is subject to the process of the courts since it is not defined specifically in the law.
I did my commute a few times with the Rattan and while I would never give up my “bike store” e-bike for this, it was a worthy substitute. It never gave out on the big hills, nor did I have to brake because I felt the bike was falling apart. The frame is a little small for 6-foot me but it only comes in one size. I really miss the low rolling drag of having road tires however and this is something that both Rattan and Ancheer could improve upon. I don’t think many people are seriously off-roading with these bikes. Put some Schwalbe Big Bens on there!

If you have dynamo-powered bicycle lights, you already own an electric-powered bicycle! Consider: as you pump your legs up and down on the pedals, you make the wheels rotate. A small dynamo (generator) mounted on the rear wheel produces a tiny current of electricity that keeps your back safety lamp lit in the dark. Now suppose you could run this process backward. What if you removed the lamp and replaced it with a large battery. The battery would kick out a steady electric current, driving the dynamo in reverse so that it spun around like an electric motor. As the dynamo/motor turned, it would rotate the tire and make the bike go along without any help from your pedaling. Hey presto: an electric bike! It may sound a bit far-fetched, but this is more or less exactly how electric bikes work.
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There is a lot of information on the internet about electric bikes. Hopefully you have found lots of useful information right here, on this website. Based on this information, you may already have a preference for a specific electric bicycle and / or (technical) components. Your friends that ride e-bikes can also advise you based on their own experiences. But there is only one way you will know if you really make the right choice: take a test drive. During a test drive you will discover how close the riding experience is to your expectations.
A response to an inquiry made to the Mass DOT/RMV indicates that Massachusetts does recognize the federal low speed electric bicycle Federal Law (15 U.S.C. § 2085) and interprets that to mean these ebikes do not require license or registration. However, some of the materials available on the RMV website do not distinguish between "Motorized Bicycle" and low power ebikes. One form, Bicycle Conversion to Motorized Bike, does document the exemption of low power ebikes.[100]
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The last 8 months we've been wrapping up some long duration testing of Statorade across different hub motor lines and performing experiments confirming its long term stability. These results have us pumped to introduce this motor cooling solution beyond DIY'ers and into wider markets. As an example, have a look at the video we below showing the effect this has on a small direct drive folding bike motor.
In principle, you would use about 100W (your own energy) for moderate pedalling at 22km/h. If you select 300% assistance (high), that will add another 300W and you can pedal almost twice as fast, i.e. about 27km/h (you will encounter increasing resistance from wind). Therefore, if you got a 400Wh battery, you got a range of about 37km at 37km/h. If go more slowly and use less support (200%), then you can drive further, e.g. 60km with a 400Wh battery. (Read more in die Die Schnellen im Vergleich)
On the other hand, the battery doesn’t lock into the bike, which means you can’t just leave it on your bike when you park at the bike rack. Anyone could walk by and simply remove your battery. That seems like an oversight to me, though perhaps the designers assumed that such a small battery would just be easy to take with you. And it is. My wife could probably lose this battery in her purse.
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