Conversion kits, on the other hand, are sold and installed separately on traditional bicycles. They are harder to setup and conceal, and require some basic mechanical ability and a little bit of ‘elbow grease’ to install. The advantage of conversion kits is that you can choose almost any standard bicycle, and you have the freedom to change or upgrade components as you go. A conversion kit will also allow you to achieve higher power and speed ratings that are not possible on most pre-built electric bike models. Kits are great for tall or heavy riders because they can opt for a larger bike, with higher power and weight carrying capacity. People living in hilly terrain may require the additional torque to handle extremely large inclines. For people who prefer a specific bike model or just love to go faster, a conversion kit offers enormous flexibility.
Photo: Zap Electric's power-assist kit turns a conventional bike into an electric one. There's a bolt-on DC electric motor (weighing just over 3kg or 7lb) just above the back wheel, behind the police officer's foot, pressing against the tire and driving it by simple friction. The motor's powered by a compact lead-acid battery (weighing about 5.5 kg or 12 lb) inside a protective nylon bag. This kit adds quite bit of weight to the bike, but gives extra range and speed when needed. Photo taken in Santa Rosa, California by Rick Tang courtesy of US DOE/NREL.
Under New Jersey law a motorized bicycle is "a pedal bicycle having a helper motor characterized in that either the maximum piston displacement is less than 50 cc, the motor is rated at no more than 1.5 brake horsepower, or it is powered by an electric drive motor and the bicycle is capable of a maximum speed of no more than 25 miles per hour on a flat surface." This would include E-bikes, meaning they must be titled and registered. However, only Mopeds approved by Motor Vehicle Services can be titled and registered.
As electric bike options continue to expand, more brands are integrating the battery more seamlessly. That makes them look sleeker (and more like a real bike). Batteries are expensive, so make sure there’s a good way to lock the battery to your bike if you’ll be keeping it outside. Overall weight is important. Some battery and motors can add 15 pounds or more to the bike. With assist, you won’t feel that much when you’re riding, but you will if you have to carry your bike up stairs or lift it onto a bike rack.
If a car is at fault in an accident with a bicycle or ebike, their motor vehicle insurance will likely cover your cost for repair and hopefully medical expenses. But what happens if you are at fault, riding an ebike illegally because you did not register it as a Moped? At best, you could be prosecuted under the law. At worst, you could be financially liable for neglect or reckless endangerment via a law suit.
According to Utah Code 41-6a-102 (17)
Some US companies, notably in the tech sector, are developing both innovative cycle designs and cycle-friendliness in the workplace. Foursquare, whose CEO Dennis Crowley "pedaled to pitch meetings ... [when he] was raising money from venture capitalists" on a two-wheeler, chose a new location for its New York headquarters "based on where biking would be easy". Parking in the office was also integral to HQ planning. Mitchell Moss, who runs the Rudin Center for Transportation Policy & Management at New York University, said in 2012: "Biking has become the mode of choice for the educated high tech worker".
Some of the Rad Wagon’s (small) flaws became apparent once I added more weight to the bike. The integrated rear rack can attach various panniers, platforms, or baskets to cary your cargo, but I was most concerned with hauling my two kiddos to school. Riding the bike with my three year old was a cinch; he held on to the bars in the caboose (available as an accessory add-on) and enjoyed the view. Adding my very tall, almost seven-year-old daughter, however, was a bit more complicated.
By 1898 a rear-wheel drive electric bicycle, which used a driving belt along the outside edge of the wheel, was patented by Mathew J. Steffens. Also, the 1899 U.S. Patent 627,066 by John Schnepf depicted a rear-wheel friction “roller-wheel” style drive electric bicycle. Schnepf's invention was later re-examined and expanded in 1969 by G.A. Wood Jr. with his U.S. Patent 3,431,994. Wood’s device used 4 fractional horsepower motors; connected through a series of gears.
Torque sensors and power controls were developed in the late 1990s. For example, Takada Yutky of Japan filed a patent in 1997 for such a device. In 1992 Vector Services Limited offered and sold an e-bike dubbed Zike. The bicycle included NiCd batteries that were built into a frame member and included an 850 g permanent-magnet motor. Despite the Zike, in 1992 hardly any commercial e-bikes were available.
Alberta identifies e-bikes as "power bicycles" and is consistent with the federal definition of "power-assisted bicycle" in MVSR CRC, c 1038 s 2. Motor output must not exceed 500 W (0.671 hp) and e-bikes cannot travel faster than 32 km/h (20 mph). Fully operable pedals are required. No driver's license, vehicle insurance, or vehicle registration is required. Operators must be 12 years of age or older. All operators are required to wear a motorcycle helmet meeting the standards set in AR 122/2009 s 112(2). A passenger is permitted only if the e-bike is equipped with a seat designated for that passenger.
There are generally two types of e-bike: throttle and pedal-assist. Throttle e-bikes, common among food delivery workers, don’t require any pedaling, just a twist of the handlebar to get moving. Wing’s e-bike is pedal-assist. The bike’s battery provides a boost while you pedal — up to 20 mph — but if you stop pedaling, the bike slows just like a regular bike.
In conformance with legislation adopted by the U.S. Congress defining this category of electric-power bicycle (15 U.S.C. 2085(b)), CPSC rules stipulate that low speed electric bicycles (to include two- and three-wheel vehicles) are exempt from classification as motor vehicles providing they have fully operable pedals, an electric motor of less than 750W (1 hp), and a top motor-powered speed of less than 20 miles per hour (32 km/h) when operated by a rider weighing 170 pounds. An electric bike remaining within these specifications is subject to the CPSC consumer product regulations for a bicycle. Commercially manufactured e-bikes exceeding these power and speed limits are regulated by the federal DOT and NHTSA as motor vehicles, and must meet additional safety requirements. The legislation enacting this amendment to the CPSC is also known as HR 727. The text of HR 727 includes the statement: "This section shall supersede any State law or requirement with respect to low-speed electric bicycles to the extent that such State law or requirement is more stringent than the Federal law or requirements." (Note that this refers to consumer product regulations enacted under the Consumer Product Safety Act. Preemption of more stringent state consumer product regulations does not limit State authority to regulate the use of electric bicycles, or bicycles in general, under state vehicle codes.)
It appears Tennessee has not passed any legislation that applies to electric bicycles. Some people think the laws pertaining to a Motorized Bicycle should be used for an electric bicycle. However, a Motorized bicycle would be a gasoline powered device per state law as it is defined as "means a vehicle with two (2) or three (3) wheels, an automatic transmission, and a motor with a cylinder capacity not exceeding fifty cubic centimeters (50cc) which produces no more than two (2) brake horsepower and is capable of propelling the vehicle at a maximum design speed of no more than thirty miles per hour (30 mph) on level ground." 
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).
E-bikes mostly use motors and battery options from a few major suppliers: Bosch, Yamaha, Shimano, and Brose. A few other brands exist, but are less reliable or powerful. Some, like the Yamaha system, have more torque, and others, like Bosch’s Active Line, are nearly silent. But, generally, all four make good options. Look for motor output (in torque), which will give you an idea of total power. Just like car engines, more torque equals more power off the line and more boost to your pedaling. But watt hours (Wh) is perhaps a more important figure to use—it takes into account battery output and life to give a more accurate reflection of power (higher Wh equals bigger range).
The federal Consumer Product Safety Act defines a "low speed electric bicycle" as a two or three wheeled vehicle with fully operable pedals, a top speed when powered solely by the motor under 20 mph (32 km/h) and an electric motor that produces less than 750 W (1.01 hp). The Act authorizes the Consumer Product Safety Commission to protect people who ride low-speed electric vehicles by issuing necessary safety regulations. The rules for e-bikes on public roads, sidewalks, and pathways are under state jurisdiction, and vary.