According to Utah Code 41-6a-102 (17)  an electric assisted bicycle is equipped with an electric motor with a power output of not more than 750 watts and is not capable of further assistance at a speed of more than 20 MPH, or at 28 MPH while pedaling and using a speedometer. New laws specifically exclude electric pedal-assisted bicycles as "motorized vehicles" and bicycles are permitted on all state land (but not necessarily on Indian Reservations, nor restrictive municipalities, such as in Park City Code 10-1-4.5 2) if the motor is not more than 750 Watts, and the assistance shuts off at 20 mph (Utah Traffic Code 53-3-202-17-a 1). E-bikes sold in Utah are required to have a sticker that details the performance capacity. Children under 14 can operate an electric bicycle if accompanied by a parent/guardian, but children under 8 may not. (Utah code 41-6a-1115.5) No license, registration, or insurance is required by the State but some municipalities may require these measures (Salt Lake City and Provo require registration).

First, think about what you need your bike for -- if it's just for a short city commute, in among traffic, then consider a smaller frame that's easy to manoeuvre through cars. The GoCycle G3 (right) is impressively nimble and its electric assistance will help propel you up to 15 mph (24 kph). Better yet, it has built-in lights, automatic gears and you can customise the amount of power the motor provides using a phone app.
"Electric power-assisted bicycle" means a vehicle that travels on not more than three wheels in contact with the ground and is equipped with (i) pedals that allow propulsion by human power and (ii) an electric motor with an input of no more than 1,000 watts that reduces the pedal effort required of the rider. For the purposes of Chapter 8 of this title, an electric power-assisted bicycle shall be a vehicle when operated on a highway.[142]
We've also released our first native 72V battery pack in a conventional downtube battery casing, assembled using the high power Samsung 27100 40T cells so that even with the small 8Ah capacity it is able to deliver 40-50A continuous currents. This is an ideal battery for fast and sporty offroad ebike builds, allowing powerful performance without the weight or complexity of most 72V setups (either two 36V packs in series or a large triangle frame battery).
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.
Maintenance of adequate tire inflation is the most frequent and troublesome concern for cyclists and many means and methods are employed to preserve pneumatic integrity. Thicker tires, thicker tubes, tire liners (of a number of rather impenetrable devices installed between the tire and tube), liquid sealing compounds squeezed into the tube, and automotive-style patch kits are all used to reliably contain the typical tire pressures of 40 to 60 pounds per square inch that are required for bicycle operation. Thin, light bicycle tires are particularly vulnerable to penetration and subsequent deflation caused by goat's heads and other burs, colloquially known as stickers. Inflation of bicycle tires to pressures higher than typical for automotive use requires special pumps. The complexity of bicycle tire maintenance and repair may cause many to not consider the bicycle for transport or leisure.
"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.
It's a solid e-bike, but it's also very heavy one for a folding bike. I found it difficult carry when the bike is folded as the carrying handle is useless, and the center of gravity is towards to the rear wheel so one has to find a place in the rear of the bike to pick it up. Even when the bike is folded, it's bulky and heavy, It's difficult to walk with it while carrying it. It's easy to hurt one's back if he or she is not careful. I would not recommend carrying this bike up or down stairways.

Since 30 May 2012, Australia has an additional new e-bike category using the European Union model of a pedelec as per the CE EN15194 standard. This means the e-bike can have a motor of 250W of continuous rated power which can only be activated by pedalling (if above 6 km/h) and must cut out over 25 km/h – if so it is classed as a normal bicycle. The state of Victoria is the first to amend their local road rules, see below.
State and Local Laws dictate your use, but cannot constitutionally supersede the federal law – Any ebike purchased within the 750W/20mph limits has no fear of being under federal motor vehicle classification, nor can any state classify them a motor vehicle. The ebike is considered a ‘bicycle’ for consumer purposes. However, the State Laws on local bike paths and local thruways may prohibit or limit ebike access. When bike path signs use word such as ‘motor vehicles’ and ‘motorbikes’ , the laws are likely referring to gas-ICE motorbikes/dirt bikes/scooters, and not ebikes. Other references to ‘motorized bicycles’ or ‘motorized vehicles’ sound more inclusive and probably are intended for either ebikes or gas mopeds. If in doubt, you always have the option to pedal unassisted by completely powering your bike down. Even though Federal law grant ebikes a bicycle status, the common consensus found in my research allows local and state law to add additional regulation to pathway and road access, just because “it has a motor”. So the Federal laws protects the consumer from the burden of motor vehicle requirements, but not the restrictions to local and state right of ways enjoyed by all non-motored bicycles.

Electric bicycles have two main methods of operation: pedal-assist and/or throttle-control. As the name implies, pedal-assist “assists” your pedaling and requires some input. With this method, a torque sensor picks up movement or stress to determine the power requirements of the rider. Everything is automated so there’s nothing to think about, just jump on and start riding. Some bikes have multiple settings, while others have just one setting with the addition of a throttle control. Depending on the setting, pedal-assistance can help a little – or a lot. At lower settings, pedal-assist is barely noticeable but helps extend your range. At higher settings, the power is quite obvious and feels like a strong wind at your back with the motor doing most of the work while you pedal along.
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.

It's a solid e-bike, but it's also very heavy one for a folding bike. I found it difficult carry when the bike is folded as the carrying handle is useless, and the center of gravity is towards to the rear wheel so one has to find a place in the rear of the bike to pick it up. Even when the bike is folded, it's bulky and heavy, It's difficult to walk with it while carrying it. It's easy to hurt one's back if he or she is not careful. I would not recommend carrying this bike up or down stairways.
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.
Legislative changes in 2012 significantly altered the classification and regulatory structure for e-bikes. The general effect was to establish electric-assisted bicycles as a subset of bicycles and regulate e-bikes in roughly the same manner as bicycles instead of other motorized devices with two (or three) wheels. Laws 2012, ch. 287, art. 3, §§ 15-17, 21, 23-26, 30, 32-33, and 41. The 2012 Legislature also modified and clarified regulation of e-bikes on bike paths and trails. Laws 2012, ch. 287, art. 4, §§ 1-4, 20.
And the last product update to kick off the year is the pilot release of our new Baserunner motor controller. We spent much of last summer and fall trying to cram an even more miniature version of the Phaserunner into compact profile that could fit inside the controller cavity of the popular Hailong downtube battery cradles, and by golly we did it. While not as powerful as the Phaserunner (just 55A max phase current, and 60V max battery voltage), the Baserunner is perfectly suited to the smaller geared and direct drive hub motors using the Higo Z910 plug. This allows for a very tidy installation with no separate controller to mount.

Not all e-bikes take the form of conventional push-bikes with an incorporated motor, such as the Cytronex bicycles which use a small battery disguised as a water bottle.[44][45] Some are designed to take the appearance of low capacity motorcycles, but smaller in size and consisting of an electric motor rather than a petrol engine. For example, the Sakura e-bike incorporates a 200 W motor found on standard e-bikes, but also includes plastic cladding, front and rear lights, and a speedometer. It is styled as a modern moped, and is often mistaken for one.[citation needed]
Even the humble bicycle hasn't escaped the clutches of modern technology. A whole herd of new e-bikes with electric motors are taking to our cities' streets. Adding a motor to a standard cycle does ramp up the price significantly, but it takes much of the effort out of cycling, making your commute to the office a sweat-free experience and allowing you to sit back and enjoy your suburban cruise.
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.
Brock had been running his esoteric shop on Cambie St. for over 30 years, pioneering the sale and production of recumbent bikes, tricycles, velomobiles, unicycles, and of course electric bicycles well before any of these things were popular. He was dabbling with early ebike conversions in the 1990's when we were still in grade school and has been for many years one of the few shops always willing to say yes to electric retrofits. We hope to still see him riding around streets of Vancouver in a white velomobile. 
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.
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.
In general, electric bicycles are considered "bicycles", rather than motor vehicles, for purposes of the code. This implies that all bicycle regulations apply to electric bicycles including operation in bike lanes. Exceptions to this include a restriction of operation on sidewalks and that a license or permit is required if the rider is younger than 17 years of age.[125]
(2) BICYCLE.--Every vehicle propelled solely by human power, and every motorized bicycle propelled by a combination of human power and an electric helper motor capable of propelling the vehicle at a speed of not more than 20 miles per hour on level ground upon which any person may ride, having two tandem wheels, and including any device generally recognized as a bicycle though equipped with two front or two rear wheels. The term does not include such a vehicle with a seat height of no more than 25 inches from the ground when the seat is adjusted to its highest position or a scooter or similar device. No person under the age of 16 may operate or ride upon a motorized bicycle.
Today I’m looking at the Rattan Challenger 350W ebike. It can be found for under $680 at Amazon (after Electrek coupon code 5AIDO2GB) shipped and includes free assembly at a local bike shop. I assembled mine at home however in about 15 minutes with the graciously supplied in box hex tool and wrenches. It is pretty straight forward – the hardest part was bolting the front light on.
"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.
Electric motorized bicycles can be power-on-demand, where the motor is activated by a handlebar mounted throttle, and/or a pedelec (from pedal electric), also known as electric assist, where the electric motor is regulated by pedaling. These have a sensor to detect the pedaling speed, the pedaling force, or both. An electronic controller provides assistance as a function of the sensor inputs, the vehicle speed and the required force. Most controllers also provide for manual adjustment.
Like most electric bikes, the Rad Wagon is also fairly heavy, weighing 72 pounds. The last drawback is that it comes in only one frame size (which I imagine helps to keep costs lower) that fits rider heights between 5 foot 2 inches and 6 foot 2 inches. My 6 foot 4 husband, however, can ride the bike just fine, so there’s some wiggle room to this range.

UPDATE (2019-03-15): I've now got more than 110 miles on the bike and still loving it. The longest ride I did was 28.5 miles and the display was still showing about two bars left on the battery. But the battery gauge is not accurate. Even when it went down to two bars it would also jump back up to 4 bars and stay that way for awhile. So it's really hard to tell how much power you have left. On one ride, after 14 miles the pedal assist stopped working all of a sudden. I stopped and re-seated the cadence sensor and it started working again. Even when PAS didn't work the throttle was still working. It hasn't happened since. There was also a lot of rattling noises which I found was the battery rattling around in the mounting bracket.
A human traveling on a bicycle at low to medium speeds of around 16–24 km/h (10–15 mph) uses only the power required to walk. Air drag, which is proportional to the square of speed, requires dramatically higher power outputs as speeds increase. If the rider is sitting upright, the rider's body creates about 75% of the total drag of the bicycle/rider combination. Drag can be reduced by seating the rider in a more aerodynamically streamlined position. Drag can also be reduced by covering the bicycle with an aerodynamic fairing. The fastest recorded unpaced speed on a flat surface is 144.18 km/h (89.59 mph)[41]

"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 first regularly produced device resembling the modern bicycle was unveiled in 1818. It was called the Dandy Horse. The two-wheeled ride-on Dandy Horse was the brainchild of German inventor Baron Karl Drais, and it featured a handle bar, a padded seat, and two inline wheels of nearly equal size. What it did not feature were pedals; this was a "running machine," thus its name in German, Laufmachine. The Dandy Horse saw only a flicker of popularity, and was largely an historical footnote within a handful of years, though its design is nearly mimicked in the child's balance bike of today.
In the Netherlands all train stations offer free bicycle parking, or a more secure parking place for a small fee, with the larger stations also offering bicycle repair shops. Cycling is so popular that the parking capacity may be exceeded, while in some places such as Delft the capacity is usually exceeded.[64] In Trondheim in Norway, the Trampe bicycle lift has been developed to encourage cyclists by giving assistance on a steep hill. Buses in many cities have bicycle carriers mounted on the front.