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.

Class 1 makes great inroads to establish set boundaries for off road/natural surface trail access for eMountain bikes. There is fierce resistance from some mountain biking purists to allow ebikes on trails. BPSA and IMBA have done good work to justify the impact of class 1 ebikes on natural surface trails, and eliminate the wear-n-tear argument, though IMBA members are not 100% on board.

In the year 1885, a British man named J.K. Stanley introduced what can fairly be described as the first modern bicycle. His Rover bike had wheels of equal size in the front and back and used a chain connecting the pedals and the rear wheel as a propulsion system. It was often marketed as a safety bike in contrast with the unstable Penny Farthing, and was a smashing success. The company went on to develop motorcycles and automobiles, remaining in business until the year 2005.
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.
However, Emu sells a little foldable number if that's your bag. The Emu Crossbar is for  town commuters that require a sweet ride that's backed up by solid Shimano Nexus hub gears and Tektro brakes, which are adequate if not the best on the market. Riding is smooth and easy, with the crank moving sensor doing its best to iron out any gaps in power delivery.
Tires vary enormously depending on their intended purpose. Road bicycles use tires 18 to 25 millimeters wide, most often completely smooth, or slick, and inflated to high pressure in order to roll fast on smooth surfaces. Off-road tires are usually between 38 and 64 mm (1.5 and 2.5 in) wide, and have treads for gripping in muddy conditions or metal studs for ice.
Experiments done in Uganda, Tanzania, and Sri Lanka on hundreds of households have shown that a bicycle can increase a poor family's income as much as 35%.[69][better source needed][70][71] Transport, if analyzed for the cost-benefit analysis for rural poverty alleviation, has given one of the best returns in this regard. For example, road investments in India were a staggering 3–10 times more effective than almost all other investments and subsidies in rural economy in the decade of the 1990s. What a road does at a macro level to increase transport, the bicycle supports at the micro level. The bicycle, in that sense, can be an important poverty-eradication tool in poor nations.
I bought this bike from a dealer after extensive research on ebikes. The Elby is on par with European commuter ebikes at a better price point, you get a lot for your $ here. Elby is the complete package commuter: lights & a USB charger (for a phone or whatever) are integrated into the motor’s power supply and wired inside the frame. Rugged fenders have heavy-duty cross braces to attach baskets and whatnot. Thick Continental tires make for a comfy ride. The step-through frame is very convenient, built stout enough to carry me (200#) and two loaded baskets down hills and around curves with perfect stability. The motor on this bike is in the rear hub, and having it behind me makes it virtually soundless. The motor (BionX 500 watt) kicks in as soon as you start pedaling, but there is a
The frame itself incorporates a series of mounts allowing you to easily trick-out the Road E+1 with a rack, fenders, or panniers to more aptly meet your touring requirements. Again, most touring purists will certainly scoff at the mere notion of pedal-assistance, however, individuals looking for more of a guided tour and less of a tour de force will swoon over the Road E+1.
Nevada Electric Bicycle (NRS 482.0287) Bicycle 20 (motor only on the flat with 170LB rider, undefined if pedal assist is allowed to go faster) 750W (it is undefined as to whether this is input or output power, but in the USA, motors are rated on output power at the shaft) No none (use caution here because of "reckless endangerment" laws) no (not a "motor vehicle")
Even the humble bicycle hasn't escaped the clutches of modern technology. A whole herd of new e-bikes with electric motors are taking to our cities' streets. Adding a motor to a standard cycle does ramp up the price significantly, but it takes much of the effort out of cycling, making your commute to the office a sweat-free experience and allowing you to sit back and enjoy your suburban cruise.

Simple, convenient, cheap, and economical—bicycles are one of the world's favorite forms of transportation. But they're not for everyone. They can be hard to pedal up and down hills or with heavy loads, and elderly or disabled people may find them impossible to manage. In the last few years, a new generation of electric bicycles has begun to revolutionize our idea of environmentally friendly transportation. These new cycles have all the convenience of cars with all the simple economy of ordinary cycles. Let's take a closer look at how they work.
The Class 3 Aventon Pace 500 urban e-bike has five levels of pedal assist and tops out at 28 mph. But the Pace has something not found on a lot of modern e-bikes. In addition to pedal power, it also has a throttle—in the case of the Pace, a small thumb paddle on the left side of the handlebar next to the control unit that holds at a steady 20 mph, no pedaling required. The bike itself has an aluminum frame, a swept-back handlebar, ergo grips, a sturdy kickstand, hydraulic disc brakes, 8-speed Shimano Altus shifting and gearing, 27.5x2.2-inch Kenda e-bike-rated tires, a saddle the size of Texas, and good ol’ classic city/commuter-bike geometry. It doesn’t come equipped with fenders or a rear rack, but you can add them. Power comes in the form of a 500-watt rear-hub motor, a semi-integrated battery on the down tube (with a range of up to 50 miles), and a backlit display unit mounted on the stem.