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.
Range is a key consideration with electric bikes, and is affected by factors such as motor efficiency, battery capacity, efficiency of the driving electronics, aerodynamics, hills and weight of the bike and rider. The range of an electric bike is usually stated as somewhere between 7 km (uphill on electric power only) to 70 km (minimum assistance) and is highly dependent on whether or not the bike is tested on flat roads or hills.[14] Some manufacturers, such as the Canadian BionX or American E+ (manufactured by Electric Motion Systems), have the option of using regenerative braking, the motor acts as a generator to slow the bike down prior to the brake pads engaging.[15] This is useful for extending the range and the life of brake pads and wheel rims. There are also experiments using fuel cells. e.g. the PHB. Some experiments have also been undertaken with super capacitors to supplement or replace batteries for cars and some SUVS.
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).
This slick-looking commuter features a clean and quiet Gates Carbon Drive belt, which eliminates the maintenance that comes with a derailleur, and an internally geared Enviolo Trekking hub, which provides a 380 percent gear range. The Embark has 650b wheels, 47mm WTB gumwall tires, full fenders with mudflaps, and integrated lights—meaning you can ride long after the sun sets—or before it rises. A Bosch Active Line Plus mid-drive motor is light and quiet and provides pedal assist up to 20 mph, and the Bosch 400Wh battery has a claimed range of 50 miles. Everything about the Embark frame screams clean, stylish, and organic.
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:

While I would have loved to see some higher end components such as disc brakes or built-in lights, the bike still works well for what you get and is a pretty good value for the price. One missing component that I feel would make a big difference is a kickstand. I’ve never seen an e-bike that didn’t come with one, outside of ultra premium multi-thousand dollar road and downhill e-bikes that try to save every gram of weight. But for a commuter, a kickstand is pretty important. You can always add a cheap $7 kickstand from Amazon, but I would have preferred they save us the step and include their own cheap kickstand.
Electric motor assisted bicycles have been banned in the State of New York and are not permitted for on-road use.[50][51] It appears the only known allowance of an electric bicycle is if it is an electric powered moped, at this time. There is a proposed bill to allow ebikes. As of May 2009, Bill A2393("Defines the term electric assisted bicycle") has been passed in the NY State Assembly[52] and its corresponding Bill S4014, sponsored by Senator Thomas Morahan, is before the NY State Senate.[53]

Different gears and ranges of gears are appropriate for different people and styles of cycling. Multi-speed bicycles allow gear selection to suit the circumstances: a cyclist could use a high gear when cycling downhill, a medium gear when cycling on a flat road, and a low gear when cycling uphill. In a lower gear every turn of the pedals leads to fewer rotations of the rear wheel. This allows the energy required to move the same distance to be distributed over more pedal turns, reducing fatigue when riding uphill, with a heavy load, or against strong winds. A higher gear allows a cyclist to make fewer pedal turns to maintain a given speed, but with more effort per turn of the pedals.
Perhaps the cleverest thing of all about the Electric Brompton is that despite all the extra stuff, it folds up exactly the same as the non-powered variety. It's so simple, and unlike certain folding bikes we could mention, what you're left with is a genuinely small thing, rather than something that's about the size of a bike with the front wheel taken off.
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