Photo: Zap Electric's power-assist kit turns a conventional bike into an electric one. There's a bolt-on DC electric motor (weighing just over 3kg or 7lb) just above the back wheel, behind the police officer's foot, pressing against the tire and driving it by simple friction. The motor's powered by a compact lead-acid battery (weighing about 5.5 kg or 12 lb) inside a protective nylon bag. This kit adds quite bit of weight to the bike, but gives extra range and speed when needed. Photo taken in Santa Rosa, California by Rick Tang courtesy of US DOE/NREL.
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.

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.
I purchased version 2.0 of this device and the manufacturer has been listening to comments from users and making running changes such as the three speeds and the rear suspension. I am an XL size user (6'2", 230lbs) and recently returned from a 26 day cruise around Europe. I rode this little scooter on cobblestones, miles and miles through the Vatican, inside ancient cities and all over the streets of San Juan upon our return stateside. There was only one time it was less than ideal and that was going uphill, on slick tile that was wet from a drizzle. It still make it, just had to lean way forward to get weight on the front wheel.

But unlike other battery mounted controllers, the Baserunner also stands on its own too. If you upgrade to a different battery model in the future that doesn't fit the cradle, simply remove the Baserunner from the base and use it as a miniature stand alone controller with your new battery pack. That's Grin thinking about your future options for you.
Electric bicycles use rechargeable batteries, electric motors and some form of control. This can be a simple as an on-off switch but is more usually an electronic pulse width modulation control. Electric bicycles developed in Switzerland in the late 1980s for the Tour de Sol solar vehicle race came with solar charging stations but these were later fixed on roofs and connected so as to feed into the electric mains.[13] The bicycles were then charged from the mains, as is common today. Battery systems in use include lead-acid, NiCd, NiMH and Li-ion batteries.
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")

Controllers for brushless motors: E-bikes require high initial torque and therefore models that use brushless motors typically have Hall sensor commutation for speed and angle measurement. An electronic controller provides assistance as a function of the sensor inputs, the vehicle speed and the required force. The controllers generally allow input by means of potentiometer or Hall Effect twist grip (or thumb-operated lever throttle), closed-loop speed control for precise speed regulation, protection logic for over-voltage, over-current and thermal protection. Bikes with a pedal assist function typically have a disc on the crank shaft featuring a ring of magnets coupled with a Hall sensor giving rise to a series of pulses, the frequency of which is proportional to pedaling speed. The controller uses pulse width modulation to regulate the power to the motor. Sometimes support is provided for regenerative braking but infrequent braking and the low mass of bicycles limits recovered energy. An implementation is described in an application note for a 200 W, 24 V Brushless DC (BLDC) motor.[43]
One of the items we demonstrated at the show is the new GMAC motor series. This is a powerful clutchless geared hub motor developed over the past 2 years in partnership with MAC motors, using a custom axle with an integrated splined torque arm. Imagine a MAC motor with perfect frame fit for modern bicycles, zero torque transmission on the dropouts, and phenomenal regenerative braking control.
Hi Levi, I’m not super familiar with Minnesota or the age limits on ebikes but Pedego just launched one specifically for younger riders (it goes a little slower). Many ebikes let you program a top speed and I feel like this is one area where you can decide as a parent. When I was 13 I had a moped and fixed up a goped with my Grandpa on his farm so… I guess it might be a family decision?
Bicycles and horse buggies were the two mainstays of private transportation just prior to the automobile, and the grading of smooth roads in the late 19th century was stimulated by the widespread advertising, production, and use of these devices.[9] More than 1 billion bicycles have been manufactured worldwide as of the early 21st century.[1][2][3] Bicycles are the most common vehicle of any kind in the world, and the most numerous model of any kind of vehicle, whether human-powered or motor vehicle, is the Chinese Flying Pigeon, with numbers exceeding 500 million.[1] The next most numerous vehicle, the Honda Super Cub motorcycle, has more than 60 million units made, while most produced car, the Toyota Corolla, has reached 35 million and counting.[4][5][6][32]

Thanks for your feedback Joe! I personally find black on white to be high contrast and abrasive. Instead, this dark gray scheme is meant to be relaxing… but if it’s uncomfortable to you or difficult to read there are ways to change your browser and even your operating system to be more comfortable using the accessibility options. Here’s a list by device type and for some browsers hope it helps!

The other motor is the G311, a front equivalent to the wonderfully silent G310 rear motors we introduced late last year. This motor will be replacing the G01 hub for our front mini geared kits. It's a tad lighter (2.3kg), much quieter (spiral gears!), but still has the features from the G01 that we loved. That means a side cable exit, ISO disk rotor compatibility, and 10mm round axle.
In the theoretical electric bike we considered up above, we had the dynamo/motor driving the back wheel directly, simply by pressing on the tire. Most electric bikes work a different way. They have compact electric motors built into the hub of the back or front wheel (or mounted in the center of the bike and connected to the pedal sprocket). Take a look at the hub of an electric bike and probably you'll see it's much fatter and bulkier than on a normal bike. You can read more about how these motors work in our main article about hub motors.