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.
One of the most important categories of ebikes is the low-cost, entry-level sector. What I call the eBigBox models.  Obviously, not everyone can’t afford a $7500 Riese and Muller and frankly a lot of people are skeptical on how much they will use and enjoy an ebike. So even if they can afford a few thousand dollars for an ebike, they might not want to put it all down on a category they aren’t sure about.
In China, e-bikes currently come under the same classification as bicycles and hence don't require a driver's license to operate. Previously it was required that users registered their bike in order to be recovered if stolen, although this has recently been abolished. Due to a recent rise in electric-bicycle-related accidents, caused mostly by inexperienced riders who ride on the wrong side of the road, run red lights, don't use headlights at night etc., the Chinese government plans to change the legal status of illegal bicycles so that vehicles with an unladen weight of 20 kg (44 lb) or more and a top speed of 30 km/h (19 mph) or more will require a motorcycle license to operate, while vehicles lighter than 20 kg (44 lb) and slower than 30 km/h can be ridden unlicensed. In the southern Chinese cities of Guangzhou, Dongguan and Shenzhen, e-bikes, like all motorcycles, are banned from certain downtown districts. There are also bans in place in small areas of Shanghai, Hangzhou and Beijing. Bans of "Scooter-Style Electric Bikes" (SSEB) were however cancelled and in Shenzhen e-bikes may be seen on the streets nowadays (2010–11).
Bicycles were introduced in the late 19th century in Europe, and by the early 21st century, more than 1 billion were in existence at a given time.[1][2][3] These numbers far exceed the number of cars, both in total and ranked by the number of individual models produced.[4][5][6] They are the principal means of transportation in many regions. They also provide a popular form of recreation, and have been adapted for use as children's toys, general fitness, military and police applications, courier services, bicycle racing and bicycle stunts.
You can learn more about the development and axle testing process on this endless-sphere thread. Our ambition is to make this splined axle design into a new standard that we deploy across our entire higher power motor lines to replace axle flats. If you're as excited as us and want to jump right into ordering, we have the first production shipment on hand available in bare motors and complete kits.
The Freedom’s motor is more powerful than the VanMoof Electrified S — 350w vs 250w — but the VanMoof is technologically superior, with touch-sensitive display, enhanced security system, and an “invisible” lock built right into the rear hub. The Dutch-made bikes are also more expensive: VanMoof’s Electrified X2 and S2 list for a discounted $2,598, while Wing’s e-bikes are available now for an “early bird” price of $1,295; if you order later, it’ll cost $1,695 — which is still almost $900 less than the VanMoof.
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.
DIY Kit ebikes – Ebikes that are home built with a DIY kit, and exceed the 750W/20mph definition, are also allowed to be bought, build, and ridden. DIY kits are throttle activated. Some of the newer systems have PAS options. Ebike kits are not unilaterally prohibited or assigned motor vehicle status, but again, legal classification and road use falls under state law.
The Super Commuter is very aptly named. The 350w Bosch motor will help you sustain speeds of up to 28mph, and the burly, 2.4-inch wide, Schwalbe Super Moto-X 650b tires will keep you secure on even the roughest city streets, and Shimano Deore hydraulic brakes provide ample stopping power. Fenders provide welcome protection from road spray so you arrive at your destination fresh, integrated lights are critical for post-sunset riding, and a side-view mirror hanging on the left side of the handlebar gives a great view of traffic around you. After all, you can ride at the speed of urban traffic on the Super Commuter. 

Speaking of which, if you're used to non-electric cycles, be aware that e-bikes are heavy and capped at 25kph or 15.5mph. In many cases, that means the bike starts to feel like its actively fighting against you, if you try to push the speed higher than that by pedalling. That's especially true with heavier bikes, for obvious reasons, and can take a while to get used to. 

To help the rider find the perfect fit, the stem is adjustable. The bike also boasts dynamo powered lights alongside hydraulic disc brakes. The bike will suit riders from 4 ft 10 to 6 ft 5, and also integrates with a child seat. The total weight is 22.5kg, making it admittedly a fairly hefty folder – but that’s fairly uniform across electric versions.
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.
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." [56]
The European Committee for Standardization (CEN) also has a specific Technical Committee, TC333, that defines European standards for cycles. Their mandate states that EN cycle standards shall harmonize with ISO standards. Some CEN cycle standards were developed before ISO published their standards, leading to strong European influences in this area. European cycle standards tend to describe minimum safety requirements, while ISO standards have historically harmonized parts geometry.[55]
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.
This electric bike received a five star. The assembly was pretty simple. I ordered a set of lights and a over rear tire carrier rack from amazon that took longer to install than it took too assemble the bike.This is a solid built by that is attractive and worthy of this price point. The build quality of this bike was very good. So far I've done a few test and it runs perfect. I've put on 50+ miles on this bike and have used it on flat ground, dirt roads, rocky trails and grassy fields. The bike runs quicker than what I expected from a small 250 W hub motor. I really like it in almost every way.

Riding position: You also may wish to check out an e-bike’s riding position before investing in it. For short trips, the riding position might not make much difference, but for long journeys, the upright "Dutch" style with pulled-back handlebars is very comfortable – particularly for tall riders. The same goes for mountain bike styles, though these bikes are not often designed to actually go off-road.
To operate the bike, you have to pedal for a second or so before the thumb throttle becomes active. This is often a cost and energy-saving measure designed into electric bicycles and scooters. Being able to start the motor from rest requires extra sensors and higher battery power. Starting the motor while it is in motion removes the need to install extra sensors in the motor (and thus removes one more possible failure or maintenance issue) and also eeks more range out of the battery by putting the energy intensive initial startup responsibility solely on the rider.
^ Consumer Product Safety Act, Pub. L. 107–319, December 4, 2002; codified at 15 U.S.C. 2085(b): The CPSC regulations do not differentiate between commercially manufactured low speed electric bicycles and those converted from ordinary bicycles by their owners using an aftermarket electric motor and battery kit, nor do they regulate the construction of electric-power bicycles using owner-built or sourced components.
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: