Across Europe, where e-bikes were embraced by the public long before the rest of the world, e-bike growth has averaged in excess of 20 percent each year between 2014 and 2017, with a whopping 25.3 percent growth to a total of two million e-bike sales in 2017. Analysts predict that strong growth will continue, with worldwide e-bike sales expected to hit $23.83 billion by 2025. A lot of that growth will be right here in the US.
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: 

The frame of a fat e-bike resembles that of a traditional bike, with front and rear portions that are a bit wider to accommodate the large tires. Your height and weight will dictate which frame size suits you best. You’ll want to go through the process of mounting and dismounting the bike to make sure you’re comfortable climbing on and off before you commit to it.
The recommendation depends a lot on what you plan to use the bike for and how you plan to ride. That said, I would recommend at least a 750 (if not 1,000) watt motor, and, if you want reasonable range, 48 or 52v cells with a minimum rating of 19ah. For shorter rides, you can use a smaller battery. Multiply battery voltage by amp hour rating to get battery watt hours. Divide the watt hours by the motors power rating to get a general idea of how many hours of heavy use you might get. I’d also recommend a mid drive as opposed to a hub drive, or to find a hub drive wheel rated to take your and the bicycle's combined weight.
Electric powered bicycles slower than 20 km/h without pedaling are legally recognized as a non-mechanically operated vehicle in China.[32] According to "TECHNOLOGY WATCH", this should help promote its widespread use.[33] Electric bicycles were banned in some areas of Beijing from August 2002 to January 2006 due to concerns over environmental, safety and city image issues. Beijing has re-allowed use of approved electric bicycles as of January 4, 2006.[34] Some cities in China still ban electric bikes.
For a more stylish ride, cast your eyes over the Coboc Rome. It's a full-size bike, with gorgeous stylings, and large wheels that let you pick up plenty of speed on the road. It has a fuss-free approach too, with its automatic motor assistance -- all you need to do is get on and ride. It's very much like any fixed gear bike you'll see on the streets, but with the additional motor, it's less effort to get about.
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.
Photo: Left: The hub motor of an electric bike. Right: If you took off the casing, this is the kind of thing you'd see. It's a simple brushless motor from a PC cooling fan, but it works in broadly the same way as a bike's hub motor. There's a static part made up of four electromagnet coils (left) and a rotating part (right) made from a permanent magnet (the gray ring) that clips onto it. When the coils are energized in sequence, they generate a magnetic field that makes the permanent magnet and fan spin around. At a glance, a hub motor looks much like an ordinary bicycle hub, but look closer and you'll find it's a lot more bulky.
Your local state may have very definite rules as to what is an e-bike, what is a moped, and what is a motorcycle. While ebikes enthusiast don’t want the motor vehicle label, it is certain that each state will define some power level and speed where that classification will apply. Your best source of information is to go directly to your state motor vehicle department website, and get a copy of the your local state vehicle codes, with NO EDITING. Only recently updated official state vehicle codes will contain all the latest changes to the laws.1 For a link to your state MVA, look here:2
Staring up the bike path of the Manhattan Bridge on a recent frigid February morning, I feel the familiar dread when confronted with a steep, uphill climb. There are few things more discouraging to a city biker — especially a fair-weather one like me — than an arduous, sweaty ascent in work clothes. But before my thighs can cramp up, I remember that I’m riding a new electric bicycle from a company called Wing.
I converted my Kona Dew Deluxe to electric with a controller and 1000 watt front wheel. The SLA batteries I tried initially were _functional_, but the bike had a range of about 6 miles @ approx. 50% throttle use. Since upgrading to the Joyisi pack, the utility of the bike has increased exponentially. I need to add a better gauge so I can drain the battery more fully between charges, but I'm getting at least 20 miles per charge, including some very aggressive uphill segments. On flat ground, the battery powers the bike to approx. 35MPH; even on really steep hills with minimal pedal assist, I do at least 15MPH. Biking 15MPH uphill with little/no effort is EPIC.
Built by a company that’s made cycling equipment for more than four decades, the Vado feels more like a traditional bicycle than almost any other ebike. Its frame and components have been tuned to provide a familiar experience, making it easy for new and long-time cyclists to jump on and start pedaling. Specialized’s heritage shines through nicely, helping separate itself from the competition in an increasingly crowded ebike market.
In 5 years of working as a bike messenger in Minneapolis, I've ridden all kinds of bikes, in all kinds of weather. I've ridden walmart mountain bikes, 80's classic steel road bikes, kitted out Treks, pretty much everything EXCEPT for fat tire bikes. Such wide tires always seemed... too much. No need for a bike that only makes itself worthwhile maybe two months out of the year, I thought.

What exactly is an electric bike? How can they be used for transportation and why do they make financial sense? These are some of the questions my site and this channel aim to help you answer. This particular video provides an overview of the Easy Motion Neo Jumper ebike and then follows me on an actual commute to work in Austin Texas.
We rode the Vado through the gauntlet, including some of the steepest hills in Palo Alto, and it easily handled everything we threw at it, maintaining a steady 20 miles per hour even on the most daunting of ascents. The bike also handles well on downhills and is both nimble and quick on city streets and paved trails. It’s even comfortable to ride for extended distances, which is vitally important for any bike built for urban settings.
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.