There's much less of a sensation of the Electrified S2 'fighting back' once you hit 15.5mph, as well. That's helped by the automatic 2-speed gear box, although this does take some getting used to. Because its cogs are very different sizes you can end up with all sorts of cadence problems as it auto-shifts from high back to low. With practice you can avoid this, or of course you could in theory fit a second cog that's closer in size to the first.
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")
When you have the electric motor turned on, it engages with your first push of the pedals. The difference in acceleration is startling compared to any other bike I've ridden. In Eco mode, I could sprint from 0 to 20mph in about 200 feet/65m. Switch to Turbo, and it's about 150/30m feet. As I mentioned above, you still have to pedal. The difference with an electric bike is the feeling of getting more bang for the buck. And if you want to be lazy, you can. Stay in third or fourth gear and you'll be able to stay around 18-19mph with minimal effort. But if you want to go much faster than 20mph, you'll need to work.
To qualify as an electric-assisted bicycle under state law they need to have a seat and fully operable pedals for human propulsion, meet federal motor vehicle safety standards, an electric motor that has a power output of not more than 1,000 watts, maximum speed of not more than 20 mph (electric motor and human power combined), disengages or ceases to function when the vehicle’s brakes are applied, two or three wheels
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 I am in an area with quite a lot of hills and steep inclines, some very steep, and the motor on the bike handles these hills effortlessly along with pedal assist. I will say I am not fit in anyway and there is no way I would have got up half of the hills I got up if it were not for the 250 watt motor on this bike, the low , medium and high pedal assist options are great and it is easy to assess which option you'll need depending on the hill.The battery was a lot heavier than I expected when holding it, feels like holiding a 3 LTR bottle of coca cola but I can forgive that

At the moment this battery is in stock but for local pickup orders only as we are going through the certification testing required for shipping. We've been keeping the 21700 cell offerings on our radar as they start to catch up with the performance specs of the more mature 18650 series and this year it looks like they are finally making the grade. Expect more from us as the year goes on. 
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]
Electric trikes have also been produced that conform to the e-bike legislation. These have the benefit of additional low speed stability and are often favored by people with disabilities. Cargo carrying tricycles are also gaining acceptance, with a small but growing number of couriers using them for package deliveries in city centres.[51][52] Latest designs of these trikes resemble a cross-between a pedal cycle and a small van.[53][54]

A lot has happened since we founded the very first eMTB specific magazine in 2013. In the beginning, manufacturers simply mounted electric motors on regular mountain bikes, more or more often than not, rather less successfully. Last year a lot of brands focused on the topic of battery integration. There are some exciting new trends and developments headed our way next season, which we take a closer look at below. 

Historically, women's bicycle frames had a top tube that connected in the middle of the seat tube instead of the top, resulting in a lower standover height at the expense of compromised structural integrity, since this places a strong bending load in the seat tube, and bicycle frame members are typically weak in bending. This design, referred to as a step-through frame or as an open frame, allows the rider to mount and dismount in a dignified way while wearing a skirt or dress. While some women's bicycles continue to use this frame style, there is also a variation, the mixte, which splits the top tube laterally into two thinner top tubes that bypass the seat tube on each side and connect to the rear fork ends. The ease of stepping through is also appreciated by those with limited flexibility or other joint problems. Because of its persistent image as a "women's" bicycle, step-through frames are not common for larger frames.
In Israel, persons above 16 years old are allowed to use pedal-assisted bicycle with power of up to 250W and speed limit of 25 km/hour. The bicycle must satisfy the European Standard EN15194 and be approved by the Standards Institution of Israel. A new law, effective January 10, 2019, states that riders under 18 who have no automobile license will need a special permit. [51] [52] Otherwise, no license or insurance is required. Other motorized bicycles are considered to be motorcycles and should be licensed and insured as such.[53] The maximum weight of the e-bike itself cannot exceed 30 kg.[54]

My homeowners (State Farm) covers bikes , but assumes $500 per bike. They will add the bikes as personal property, but the premium is excessive (about $300/year per bike, and we have four bikes). I did increase our personal umbrella liability coverage, and it covers us if family members any sort of accident on our e-bikes that injures us or others or others' property, though only covers $500 each for our own bikes (under the homeowners coverage). It was not very expensive to increase the umbrella policy (as it resulted also in a reduced rate on our car insurance).
In the 1870s many cycling clubs flourished. They were popular in a time when there were not cars on the market and the principal mode of transportation was horse-drawn vehicles, such the horse and buggy or the horsecar. Among the earliest clubs was The Bicycle Touring Club, which has operated since 1878. By the turn of the century, cycling clubs flourished on both sides of the Atlantic, and touring and racing became widely popular. The Raleigh Bicycle Company was founded in Nottingham, England in 1888. It became the biggest bicycle manufacturing company in the world, making over two million bikes per year.[31]
Electric bikes are considered motorcycles in Hong Kong, and therefore need type approval from the Transport Department, just as automobiles. All electric bikes available in Hong Kong fail to meet the type approval requirement, and the Transport Department has never granted any type approval for an electric bike, making all electric bikes effectively illegal in Hong Kong. Even if they got type approval, the driver would need a motorcycle driving license to ride.[35] As a side note, Hong Kong doesn't have a moped vehicle class (and therefore no moped driving license), and mopeds are considered motorcycles too.

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Electric mountain bikes have garnered a lot of attention for their ability to help riders go higher, further, and faster on the trail. As a result, there have been some impressive new eMTB models to hit the market in recent years, making it easier than ever to head off-road. Our favorite is the Haibike SDURO HardNine, which comes equipped with a 350-watt Bosch Performance CX drive and a 500 watt-hour battery. This gives it a range of up to 70 miles, along with a top speed of 20 mph, which is plenty fast on singletrack.
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.

China has experienced an explosive growth of sales of non-assisted e-bikes including scooter type, with annual sales jumping from 56,000 units in 1998 to over 21 million in 2008,[72] and reaching an estimated fleet of 120 million e-bikes in early 2010.[2][73] This boom was triggered by Chinese local governments' efforts to restrict motorcycles in city centers to avoid traffic disruption and accidents. By late 2009 motorcycles are banned or restricted in over ninety major Chinese cities.[72] Users began replacing traditional bicycles and motorcycles and e-bike became an alternative to commuting by car.[2] Nevertheless, road safety concerns continue as around 2,500 e-bike related deaths were registered in 2007.[73] By late 2009 ten cities had also banned or imposed restrictions on e-bikes on the same grounds as motorcycles. Among these cities were Guangzhou, Shenzhen, Changsha, Foshan, Changzhou, and Dongguang.[72][73]
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.
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