In built up cities around the world, urban planning uses cycling infrastructure like bikeways to reduce traffic congestion and air pollution. A number of cities around the world have implemented schemes known as bicycle sharing systems or community bicycle programs. The first of these was the White Bicycle plan in Amsterdam in 1965. It was followed by yellow bicycles in La Rochelle and green bicycles in Cambridge. These initiatives complement public transport systems and offer an alternative to motorized traffic to help reduce congestion and pollution. In Europe, especially in the Netherlands and parts of Germany and Denmark, bicycle commuting is common. In Copenhagen, a cyclists' organization runs a Cycling Embassy that promotes biking for commuting and sightseeing. The United Kingdom has a tax break scheme (IR 176) that allows employees to buy a new bicycle tax free to use for commuting.
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.
Different gears and ranges of gears are appropriate for different people and styles of cycling. Multi-speed bicycles allow gear selection to suit the circumstances: a cyclist could use a high gear when cycling downhill, a medium gear when cycling on a flat road, and a low gear when cycling uphill. In a lower gear every turn of the pedals leads to fewer rotations of the rear wheel. This allows the energy required to move the same distance to be distributed over more pedal turns, reducing fatigue when riding uphill, with a heavy load, or against strong winds. A higher gear allows a cyclist to make fewer pedal turns to maintain a given speed, but with more effort per turn of the pedals.
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")
Electric bicycle fits under the definition of "moped" under Kentucky law. You don't need tag or insurance, but you need a driver's license. "Moped" means either a motorized bicycle whose frame design may include one (1) or more horizontal crossbars supporting a fuel tank so long as it also has pedals, or a motorized bicycle with a step-through type frame which may or may not have pedals rated no more than two (2) brake horsepower, a cylinder capacity not exceeding fifty (50) cubic centimeters, an automatic transmission not requiring clutching or shifting by the operator after the drive system is engaged, and capable of a maximum speed of not more than thirty (30) miles per hour Helmets are required.
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, and reaching an estimated fleet of 120 million e-bikes in early 2010. 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. Users began replacing traditional bicycles and motorcycles and e-bike became an alternative to commuting by car. Nevertheless, road safety concerns continue as around 2,500 e-bike related deaths were registered in 2007. 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.
The frame of an electric bike also has to be slightly different. The main part of the frame (the bit that supports your weight) is usually made from lightweight aluminum alloy: the lighter the frame, the lighter the weight of the bike overall, and the further it can travel before you need to recharge the batteries. The spokes on the wheel also have to be stronger than the thin spokes on a traditional bicycle. That's because the electric motor in the hub spins the wheel with a lot of turning force (known as torque) and, if the spokes were ordinary lightweight ones, they could bend or buckle.
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.
Parliament has decided to approve the speed pedelec – a type of super electric bike that can reach speeds of up to 45 km/hour – for riding on cycle paths. Danish Parliament has decided that as of July 1 2018 those operating the super bikes only need to have turned 15 and wear a helmet, while the licence and number-plate demands will no longer be in play. 
If you are a person who enjoys riding a bike casually at a typical bike path speed (10-15mph), and you like the idea of an ebike push up a hill, against the wind or to relieving a sore knee, then your market for a fully legally defined ebike is very broad and your practical use only has a few limitations. Most ebikes will meet your needs and expectation. I would estimate that 85% of the electric bikes on the market are 100% compliant meeting the federal definition. I encourage you to take the plunge and get a good quality ebike and ride more with assist. Do so with the confidence that electric bikes are here to stay. Coexisting with pedestrians and other cyclist will become a normal part of cycling life.
The days when eMTBs were defined solely by the power of their motors and the size of their batteries are over. Riding performance has become the most important metric. In that pursuit, manufacturers are increasingly developing eMTBs with less power and battery capacity, which in turn handle more like regular mountain bikes. FOCUS started this movement some time ago with its Project-Y concept and later presented the FOCUS RAVEN² PRO, the first production model in a new category of bikes. However this sporty ride only convinced a handful of riders. Meanwhile, Lapierre and BULLS have both announced full-suspension trail bikes featuring the lightweight FAZUA motor for next year. It remains to be seen how many other brands will jump on board this bandwagon – but the rumour mill has already started rumbling. Moreover, it is only a matter of time before the next motor manufacturer will release its own small, lightweight motor.
Geared Hub Motors – Most pre-built e-bikes use brushless geared hub motors. These motors have internal planetary gears that help transfer power from the motor to the wheel. Because of the internal gearing, these motors provide excellent torque but are limited in top speed. On the plus side, the improved torque means better take-off power and hill climbing ability. Plus, less wattage is required to get the motor turning and they’re typically small and lightweight. On pre-built e-bikes, these motors range from 200w-500w and go up to 20mph. But some aftermarket kits can be as powerful as 1000w, with increased top speeds and huge amounts of torque (ideal for extremely hilly terrain). Besides lower top speeds, these motors tend to be expensive and it’s possible the gears will eventually wear out and need to be replaced (this is highly unlikely, they las quite a long time). Good examples are Ancheer bikes.
What's the Centros like? Big and heavy, but with enough power to overcome that, it really reminded me of a more upmarket Volt Pulse. You do tend to find that the weightier e-bikes give more of a feeling of speed, even though you're only doing 20mph or so at the absolute most (only up to 15mph with electrical assistance so you'll need leg muscles or a downward incline to get to that outlandish velocity).
"Medical Exemptions" are also a standard right in the State of Texas for motorcycles & even bicyclists. Through Texas's motorcycle helmet law (bicycle helmet laws from city ordinances), it is only required for those 21 years old or younger to wear a helmet. However, a medical exemption,  written by a certified licensed medical physician or licensed chiropractor, which exempts one from wearing a helmet, can be used for bicyclists if helmets are required.
As of May 19, 2009, Nevada amended its state transportation laws to explicitly permit electric bicycles to use any "trail or pedestrian walkway" intended for use with bicycles and constructed with federal funding, and otherwise generally permits electric bicycles to be operated in cases where a regular bicycle could be. An electric bicycle is defined as a two- or three-wheeled vehicle with fully operable pedals with an electric motor producing up to 1 gross brake horsepower and up to 750 watts final output, and with a maximum speed of up to 20 miles per hour on flat ground with a 170 pound rider when powered only by that engine. (AB441, amending NRS 480, 482 and other sections)
The oldest patent for an electric bike I've been able to find at the US Patent and Trademark Office is this one, by Ogden Bolton, Jr. of Canton Ohio, which was filed in September 1895 and granted three months later. You can see from these original diagrams that it bears an amazingly close resemblance to modern electric bikes. In the general picture on the left, you can see there's a hub motor on the rear wheel (blue), a battery suspended from the frame (red), and a simple handlebar control to make the thing stop and go. In the more detailed cutaway of the hub motor on the right, you can see there's a six-pole magnet in the center (orange) bolted to the frame and an armature (made from coiled wire, yellow) that rotates around it when the current is switched on. It's quite a hefty motor even by modern standards; Ogdon mentions "a heavy current at low voltage—for instance, to carry one hundred amperes at ten volts." So that's 1000 watts, which is about twice the power of a typical modern bike hub motor.
If you're taking your bike inside, consider one that folds up. The Cyclotricity Wallet has a motor in the front wheel, which takes you up to speed either by assisting your pedalling, or you can sit back and use the throttle by itself. Its folding design makes it slightly easier to get in and out of a building, but its hefty weight means you still won't find it easy to carry onto public transport.
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.
The "Dandy horse", also called Draisienne or Laufmaschine, was the first human means of transport to use only two wheels in tandem and was invented by the German Baron Karl von Drais. It is regarded as the modern bicycle's forerunner; Drais introduced it to the public in Mannheim in summer 1817 and in Paris in 1818. Its rider sat astride a wooden frame supported by two in-line wheels and pushed the vehicle along with his or her feet while steering the front wheel.
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.