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.
"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, [59][60][61][62][63][64] 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.
The handlebars connect to the stem that connects to the fork that connects to the front wheel, and the whole assembly connects to the bike and rotates about the steering axis via the headset bearings. Three styles of handlebar are common. Upright handlebars, the norm in Europe and elsewhere until the 1970s, curve gently back toward the rider, offering a natural grip and comfortable upright position. Drop handlebars "drop" as they curve forward and down, offering the cyclist best braking power from a more aerodynamic "crouched" position, as well as more upright positions in which the hands grip the brake lever mounts, the forward curves, or the upper flat sections for increasingly upright postures. Mountain bikes generally feature a 'straight handlebar' or 'riser bar' with varying degrees of sweep backwards and centimeters rise upwards, as well as wider widths which can provide better handling due to increased leverage against the wheel.
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.
As the managing editor of Ars Technica, one of my duties is to monitor the daily torrent of news tips and PR emails. The overwhelming majority of them is deleted after a glance, and the news tips and story ideas are passed along to the appropriate writer. Sometimes a product announcement will catch my eye, and I will follow up. Once in a blue moon, I'll say, "please send me one so that I may review it." And that's how I ended up riding an electric bike around the Chicago suburbs for two weeks.

Earlier UK regulations required that the motor has an average power output limited to 200 W (250 W for tricycles and tandems) and weight limited to 40 kg (60 kg for tricycles and tandems). These regulations must come in-line with the EU regulations by (find deadline). For models sold before June 2003, e-bikes conforming to the speed, weight and power limits may also be considered pedal cycles. Electric bikes with higher power outputs, or those not meeting the "pedelec" definition are now treated as motorcycles and require a license.
One of the profound economic implications of bicycle use is that it liberates the user from oil consumption.(Ballantine, 1972) The bicycle is an inexpensive, fast, healthy and environmentally friendly mode of transport. Ivan Illich stated that bicycle use extended the usable physical environment for people, while alternatives such as cars and motorways degraded and confined people's environment and mobility.[105] Currently, two billion bicycles are in use around the world. Children, students, professionals, laborers, civil servants and seniors are pedaling around their communities. They all experience the freedom and the natural opportunity for exercise that the bicycle easily provides. Bicycle also has lowest carbon intensity of travel.[106]
Generally they are considered vehicles (like motorcycles and pedal cycles), so are subject to the same rules of the road. Regulations may define maximum power output and for electric bikes may or may not require an interlock to prevent use of power when the rider is not pedaling. In some cases regulatory requirements have been complicated by lobbying in respect of the Segway HT.
This 150mm-travel e-mtb tackles big descents, shines on flowy trails, and provides the boost you need for the trip back. Pedal assist comes from Shimano’s 6.2-pound STePS E8000 motor with a 20mph boost. Shifting is motorized too, with Shimano’s exemplary XT Di2 drivetrain providing the most precise and consistent shifts a mountain bike can have. The fun comes from the E-Core’s 150mm of front and rear travel courtesy of a RockShox Yari fork and Deluxe RT shock. Both can be locked out for long, fire-road type climbs, though on an e-bike that feature feels less necessary.
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 bicycle usage worldwide has experienced rapid growth since 1998. It is estimated that there were roughly 120 million "ebikes" on the road in China as of early 2010.[1]. The “Electric Bikes Worldwide Reports – 2010 Update”[2] estimates that 1,000,000 electric bicycles will be sold in Europe in 2010. The same report estimates that sales in the USA will reach roughly 300,000 in 2010, doubling the number sold in 2009.
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.[106]
European Union directive 2002/24/EC exempts vehicles with the following definition from type approval: "Cycles with pedal assistance which are equipped with an auxiliary electric motor having a maximum continuous rated power of 0.25 kW, of which the output is progressively reduced and finally cut off as the vehicle reaches a speed of 25km/h (15.5mph) or if the cyclist stops pedaling." This is the de facto definition of an electrically assisted pedal cycle in the EU. As with all EU directives, individual member countries of the EU are left to implement the requirements in national legislation.
These small complaints prove that the Rad Wagon isn’t perfect. But its overwhelmingly positive qualities clearly outweigh the drawbacks. The Rad Wagon handled beautifully on city streets, accelerating with ease and maintaining a charge for extended range. Rad Power bikes also offers an array of helpful accessories—think racks, baskets, panniers, and platforms—that make the bike nearly as convenient as a car. Time and time again I passed cars stuck in traffic on their daily commute and couldn’t help but wondering: Why don’t more people switch from cars to an e-bike?
Most electric bicycles can be locked using keys supplied by the manufacturer. The key is usually inserted into a switch, which is commonly found on the bicycle's handlebars or on one side of the motor compartment. When switched to the "Off" position, the electrical drive system cannot be turned on. In areas of high risk for bicycle theft, these locking mechanisms are used in conjunction with coil or U locks.

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. 
I've put almost1 thousand miles on the bike in 2 months, and so far I love it! Using the just electric mode only go about 12-13 miles an hour on level ground and I only weigh about 160. So it's not real powerful. But on pedal assist it works great up hills. It folds up quick and easy. It's a real pain putting the rear wheel back on if you get a flat so I recommend getting tire linners. It also would be nice if you could charge the battery off the bike. I think it's well worth the money! Great bike ! Its made it through lots of abuse even through miles of down pouring rain!
This slick-looking commuter features a clean and quiet Gates Carbon Drive belt, which eliminates the maintenance that comes with a derailleur, and an internally geared Enviolo Trekking hub, which provides a 380 percent gear range. The Embark has 650b wheels, 47mm WTB gumwall tires, full fenders with mudflaps, and integrated lights—meaning you can ride long after the sun sets—or before it rises. A Bosch Active Line Plus mid-drive motor is light and quiet and provides pedal assist up to 20 mph, and the Bosch 400Wh battery has a claimed range of 50 miles. Everything about the Embark frame screams clean, stylish, and organic.

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]
Oklahoma the following restrictions on the operation of Electric-Assisted Bicycle in 47 O.S. 11-805.2 [123] as follows: 1. Possess a Class A, B, C or D license, but shall be exempt from a motorcycle endorsement; 2. Not be subject to motor vehicle liability insurance requirements only as they pertain to the operation of electric-assisted bicycles; 3. Be authorized to operate an electric-assisted bicycle wherever bicycles are authorized to be operated; 4. Be prohibited from operating an electric-assisted bicycle wherever bicycles are prohibited from operating; and 5. Wear a properly fitted and fastened bicycle helmet which meets the standards of the American National Standards Institute or the Snell Memorial Foundation Standards for protective headgear for use in bicycling, provided such operator is eighteen (18) years of age or less.
Some argue, that an ebike should have some kind of front suspension, i.e. be able to cope with potholes at higher speed or off-road conditions. However, in countries with flat roads (e.g. Switzerland, Germany or Holland) you don't need that extra weight for extra price if you stay on roads and/or drive slowly in difficult terrain. Some makes (like the Stromer) let you choose.

The Class 3 Aventon Pace 500 urban e-bike has five levels of pedal assist and tops out at 28 mph. But the Pace has something not found on a lot of modern e-bikes. In addition to pedal power, it also has a throttle—in the case of the Pace, a small thumb paddle on the left side of the handlebar next to the control unit that holds at a steady 20 mph, no pedaling required. The bike itself has an aluminum frame, a swept-back handlebar, ergo grips, a sturdy kickstand, hydraulic disc brakes, 8-speed Shimano Altus shifting and gearing, 27.5x2.2-inch Kenda e-bike-rated tires, a saddle the size of Texas, and good ol’ classic city/commuter-bike geometry. It doesn’t come equipped with fenders or a rear rack, but you can add them. Power comes in the form of a 500-watt rear-hub motor, a semi-integrated battery on the down tube (with a range of up to 50 miles), and a backlit display unit mounted on the stem.

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.

From the beginning and still today, bicycles have been and are employed for many uses. In a utilitarian way, bicycles are used for transportation, bicycle commuting, and utility cycling. It can be used as a 'work horse', used by mail carriers, paramedics, police, messengers, and general delivery services. Military uses of bicycles include communications, reconnaissance, troop movement, supply of provisions, and patrol. See also: bicycle infantry.
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.

I would add that the point of the article seems to encourage ebikers to “know the state laws” and be confident within those boundaries. To D McCarthy’s question, if your state has a definition for ebikes and classifies them as bicycles and affords access as bicycles, AND, your particular ebike is built within those specifications, then you should be able to ride that section of road with confidence. Just my 2C.

Photo: Could solar power be the future of electric bicycles? The large solar panel mounted over the back wheel of this experimental bike powers an electric motor connected by a chain drive to the back wheel, helping the rider when he doesn't feel like pedaling. Using clean, green solar power would remove the problem of having to charge electric bikes with electricity generated from fossil fuels—and help to extend their range significantly. Photo by Warren Gretz courtesy of US DOE/NREL.
As of 2005, where Federal funds have been used in the construction of bicycle or pedestrian paths motor vehicles including electric bicycles (here defined as having a motor weighing less than Template:Convert) are not permitted unless State or Local regulations permit [25]. This was known as the Transportation Equity Act for the 21st Century (TEA-21), or Public Law 105-178, or by its 2003 re-authorization which expired in 2005 the Safe, Accountable, Flexible, Efficient Transportation Equity Act (SAFETEA-LU).[26][27]
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
In Opinion No. 2007-00602 of the Attorney General, Jim Hood clarified that a "bicycle with a motor attached" does not satisfy the definition of "motor vehicle" under Section 63-3-103. He stated that it is up to the authority creating the bike lane to determine if a bicycle with a motor attached can be ridden in bike lanes. No specifications about the motor were made.
The Domane+ e-road bike is the electric version of Trek’s popular Domane. It’s designed for riders who appreciate that bike’s reliable comfort and IsoSpeed technology but want the added fun and function of e-assist. It’s also the ideal companion for anyone coming back from injury, slower riders who want to mix it up with a speedy group, and couples with different fitness levels. A Bosch Performance Line Speed motor provides a very welcome 28 mph of pedal assist, and the 500Wh Powertube battery sleekly integrates into the down tube. Also integrated: front and rear lights, which are powered by the battery—no charging required.