Attitudes to electric bikes have changed in recent years. For a long time they were seen by cyclists as 'cheating' and by non-cyclists as being just like a bike, but uglier and far more expensive. This new breed of best-in-class electric bikes feel more natural, look more normal, and people are coming around to the idea that a ride with the convenience of a bike but without all the sweat and effort is a Very Good Thing. 

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.
By 2001 the terms, E-Bikes, power bike, pedelec, assisted bicycle and power-assisted bicycle where commonly used to describe electric bicycles. E-bike, according to Google, is a term that has increased in trend. This term generally referred to an electric bicycle which used a throttle. The terms Electric Motorbike or E-Motorbike have been used to describe more powerful models which attain up to 80 km/h.
The great majority of modern bicycles have a frame with upright seating that looks much like the first chain-driven bike.[7][8][9] These upright bicycles almost always feature the diamond frame, a truss consisting of two triangles: the front triangle and the rear triangle. The front triangle consists of the head tube, top tube, down tube, and seat tube. The head tube contains the headset, the set of bearings that allows the fork to turn smoothly for steering and balance. The top tube connects the head tube to the seat tube at the top, and the down tube connects the head tube to the bottom bracket. The rear triangle consists of the seat tube and paired chain stays and seat stays. The chain stays run parallel to the chain, connecting the bottom bracket to the rear dropout, where the axle for the rear wheel is held. The seat stays connect the top of the seat tube (at or near the same point as the top tube) to the rear fork ends.

We need to support and put our purchasing power behind ebikes sold in the U.S. that are trying to comply with the California rules which allow 500w and 750w nominal motors and establish 3 classes. If these bikes can create a big enough footprint in the market then future U.S. bike rules may universally adopt these standards. It is better than engaging in regulation showdowns without any standardized and unified proposal on the part of the Electric Bike Community.

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]
E-bikes use rechargeable batteries and the lighter ones can travel up to 25 to 32 km/h (16 to 20 mph), depending on local laws, while the more high-powered varieties can often do in excess of 45 km/h (28 mph). In some markets, such as Germany as of 2013, they are gaining in popularity and taking some market share away from conventional bicycles,[1] while in others, such as China as of 2010, they are replacing fossil fuel-powered mopeds and small motorcycles.[2][3]

I would add that the point of the article seems to encourage ebikers to “know the state laws” and be confident within those boundaries. To D McCarthy’s question, if your state has a definition for ebikes and classifies them as bicycles and affords access as bicycles, AND, your particular ebike is built within those specifications, then you should be able to ride that section of road with confidence. Just my 2C.
In the early 1860s, Frenchmen Pierre Michaux and Pierre Lallement took bicycle design in a new direction by adding a mechanical crank drive with pedals on an enlarged front wheel (the velocipede). This was the first in mass production. Another French inventor named Douglas Grasso had a failed prototype of Pierre Lallement's bicycle several years earlier. Several inventions followed using rear-wheel drive, the best known being the rod-driven velocipede by Scotsman Thomas McCall in 1869. In that same year, bicycle wheels with wire spokes were patented by Eugène Meyer of Paris.[22] The French vélocipède, made of iron and wood, developed into the "penny-farthing" (historically known as an "ordinary bicycle", a retronym, since there was then no other kind).[23] It featured a tubular steel frame on which were mounted wire-spoked wheels with solid rubber tires. These bicycles were difficult to ride due to their high seat and poor weight distribution. In 1868 Rowley Turner, a sales agent of the Coventry Sewing Machine Company (which soon became the Coventry Machinists Company), brought a Michaux cycle to Coventry, England. His uncle, Josiah Turner, and business partner James Starley, used this as a basis for the 'Coventry Model' in what became Britain's first cycle factory.[24]
The Footloose has no chain, however -- it's entirely electrically driven. It takes very little effort to get to your destination, meaning you arrive at work without having broken a sweat. The downside is that when you run out of power, you're not going anywhere. And pedalling from a standstill, waiting for the motor to kick in, is an odd sensation that takes some getting used to.
In the 1890s, electric bicycles were documented within various U.S. patents. For example, on 31 December 1895 Ogden Bolton Jr. was granted Template:US Patent for a battery-powered bicycle with “6-pole brush-and-commutator direct current (DC) hub motor mounted in the rear wheel.” There were no gears and the motor could draw up to 100 amperes (A) from a 10-V battery.[3]
I'm one of the hardcore cyclists at Ars, along with Jay Timmer and his new-as-of-last-fall road bike as well as copyeditor Kerry Staurseth. I love cycling, and it was a major factor in my dropping 120lb over a 12-month period starting in the summer of 2009. My daily rider/errand-runner is a 1998 Gary Fisher Marlin mountain bike. For longer rides, I use my 2009 Trek XO2 cyclecross bike. I've made a few modifications to it, including removing the bumpy cyclecross tires and swapping out the front 46-tooth chainring for a 50-tooth one. I went with a cross bike over a road bike because I'm still a Clydesdale, and I like the slightly longer wheelbase of a cross bike. I've also briefly owned a 2011 Trek Madone 5.9, which I sold not long after I bought it due to severely screwing up my right knee.
Most electric bicycles can be classified as zero-emissions vehicles, as they emit no combustion byproducts. The environmental effects of electricity generation and power distribution and of manufacturing and disposing of (limited life) high storage density batteries must be taken into account. Even with these issues considered, electric bicycles will have significantly lower environmental impact than conventional automobiles, and are generally seen as environmentally desirable in an urban environment. The small size of the battery pack on an electric bicycle, relative to the larger pack used in an electric car, makes ebikes very good candidates for charging via solar power or other renewable energy resources. Sanyo capitalized on this benefit when it set up "solar parking lots," in which ebike riders can charge their vehicles while parked under photovoltaic panels.[16]
The battery is the pedelec’s power source. It supplies the motor with the electrical energy that is required to provide power assistance when cycling. So it is hardly surprising that there is frequent discussion and “talking shop” about the eBike’s battery in particular. What is the difference between batteries? How far can you go on a fully charged battery? What do you have to remember about storage? Thomas Raica, head of technical customer application, here provides information and advice.
Included in this shipment are the much awaited 3540 motors with their slick "UFO" design. These are the replacements for the older square style "H" motors, you may have noticed that this change was implemented last year with the 3525 front and rear motors. As always, we have the motors customized with a 10K NTC thermistor for thermal rollback using the CA3.
At the top end, the 20mph speed limit isn't an absolute, like the speed of light. It's just the most you'll get from the motor. I was able to get it up to 28mph on a flat road (there are no other roads where I live) in Turbo mode and 8th gear, but it took hard work to get there and maintain the speed. The easiest comparison is my mountain bike, where I've hit 23mph on that same stretch of road—and that took a heck of a lot of effort. Exactly how much effort does it take to ride? I have a 15-mile route that I ride on both my mountain bike and cyclecross bike. According to my Apple Watch, I generally burn around 1,400 or so calories on a brisk ride. I'll probably average around 13mph or so on my Marlin and between 16 and 17.5mph on my XO2. I averaged 14.9mph and burned a hair over 1,000 calories with the Bulls Cross E8.
This article did a good job of trying to justify the assist speed limits but fell short of detailing how that can ever be effectively enforced. In reality the only enforcement that is going to work is applied speed limits to use of bikes and ebikes. For example, it makes sense that a bike lane on a street that the speed limit of vehicles is the speed limit of the bikes/ebikes. On sidewalks and shared pedestrian paths the speed limit probably does need to be in the 15-20mph range to match traditional bikes speeds on those paths.

Would an e-bike that used a trailing generator to power the electric motor still be considered an e-bike? The purpose of the generator is allow greater distances to be traveled and all day riding. The gen-set that I am looking at uses a 49 cc gas engine with a 12 volt generator, this would be from the ground up build using a 1 hp electric motor. This seems to stay within the state laws of AZ. where I reside. Thanks for your thoughts.
On the other hand, the battery doesn’t lock into the bike, which means you can’t just leave it on your bike when you park at the bike rack. Anyone could walk by and simply remove your battery. That seems like an oversight to me, though perhaps the designers assumed that such a small battery would just be easy to take with you. And it is. My wife could probably lose this battery in her purse.
I would advocate you ride legal within the laws of your state. I would also look into some kind of liability rider or umbrella policy with your home owner’s policy, which covers your personal liability and theft. Get your bike registered; wear your helmet, eye protection, whatever is required by state law so that if an accident occurs and you are at fault, there is no legal recourse. Even if you own a 750W/20mph ebike that meets the definition of a bicycle, any at-fault cyclist may still be denied coverage by stingy insurance companies who want to support their clients. Your health insurance will usually cover your medical bills, but the costs of an expensive ebike may be lost.