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." 
In Nova Scotia power-assisted bicycles are classified similarly to standard pedal bicycles. The Nova Scotia Motor Vehicle Act defines a power-assisted bicycle as a bicycle with an electric motor of 500 watts or less, with two wheels (one of which is at least 350 mm) or four wheels (two of which are at least 350mm). PABs are permitted on the road in the province of Nova Scotia as long as you wear an approved bicycle helmet with the chinstrap engaged. They do not have to meet the conditions defined within the Canadian Motor Vehicle Safety Regulations for a motorcycle (they are not classed as "motor vehicles"), but they do have to comply with federal regulations that define Power Assisted Bicycles.
Nebraska defines a Moped as "a bicycle with fully operative pedals for propulsion by human power, an automatic transmission, and a motor with a cylinder capacity not exceeding fifty cubic centimeters which produces no more than two brake horsepower and is capable of propelling the bicycle at a maximum design speed of no more than thirty miles per hour on level ground."
Vehicles with an electric power and power of less than 300W are classified as "not a motor vehicle". Such electric bicycles must comply with the same rules as bicycles. You must wear a helmet even on a scooter or bike under 300W. If the power is over 300W or a combustion engine is used it is a "low powered vehicle" and the moped rules apply. Specifically, a drivers license and registration are required.
Since fat tire electric bikes are suitable for a wider variety of situations than a standard cruiser or commuter e-bike, they have the potential to appeal to more people. For example, hunters and campers are ideal candidates for fat tire e-bikes, as they’ll benefit greatly from the heavy-duty tires and powerful motor when they’re navigating difficult wooded trails with lots of gear.
Hmm, that’s unfortunate. I actually have a doctors note that I carry along which recommends the use of an assisted bicycle. I ride thoughtfully and have never been asked to show it. I cannot comment on the federal parks, perhaps they are not aware of the federal law classifying electric assist bikes that perform at or below 20 mph and 750 watts as bicycles. Having a note and this information would be a good response if you were questioned.
Many newer or smaller companies only design and market their products; the actual production is done by Asian companies. For example, some 60% of the world's bicycles are now being made in China. Despite this shift in production, as nations such as China and India become more wealthy, their own use of bicycles has declined due to the increasing affordability of cars and motorcycles. One of the major reasons for the proliferation of Chinese-made bicycles in foreign markets is the lower cost of labor in China.
Because the power is applied through the chain and sprocket, power is typically limited to around 250–500 watts to protect against fast wear on the drivetrain. An electric mid-drive combined with an internal gear hub at the back hub may require care due to the lack of a clutch mechanism to soften the shock to the gears at the moment of re-engagement. A continuously variable transmission or a fully automatic internal gear hub may reduce the shocks due to the viscosity of oils used for liquid coupling instead of the mechanical couplings of the conventional internal gear hubs.
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.
Thanks for your excellent article. I’ve been riding ebike for about 16 years. My first electric bike was a Meridian pedal assist bike. I just up graded to a new bike. I’m 73, so I wanted a pedal assist bike that had a throttle. I researched for several months and bought what I think is the best bike for the money. It’s a Rad Rover 2017 fat bike. It has a 750 watt mother with a 48 volt 11.6 amp battery. It’s a fantastic bike, that is a lot of fun to ride. You might want to check it out and add it to your list of bikes. Rad Rover also make a city commuter bike, a cargo bike and a folding bike. You can’t beat their price for a quality bike. Thanks again for both of your articles. They were very informative.
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.
How do the State Laws relate to the 2001 Federal Law? This is a difficult question to answer and know how they apply to you individually. From the Federal Law, one would hope that your purchased ebike is simply classified as a bicycle, with all the rights and privileges allotted to a normal cyclist. However, State Laws are confusing because they may be more restrictive in parts and add other requirements. About 30 U.S. states still have confusing regulations around them. Either the bikes are technically classified as mopeds or motor vehicles, or they have equipment, licensing or registration requirements that cause problems for riders. Thanks to the People-For-Bikes/Bicycle Product Suppliers Association (BPSA) partnership with local advocacy groups, they have been able to make the case for streamlining state regulations so that e-bikes are essentially treated like regular bicycles.4
Electric-assisted bicycles are treated as human-powered bicycles, while bicycles capable of propulsion by electric power alone face additional registration and regulatory requirements as mopeds. Requirements include electric power generation by a motor that cannot be easily modified, along with a power assist mechanism that operates safely and smoothly. In December 2008, The assist ratio was updated as follow: