While we won't be there in person, a number of vehicles will be at the show featuring the new Grin products like the GMAC Hub Motors, RH212 direct drive motors, All Axle hubs, and the Baserunner and Phaserunner_L10 controllers. If you're lucky enough to attend then check out Booth A.18 and Booth 3.12 for some velomobiles and cargo vehicles running this gear.
Put the wheel with the electric hub on your bike and connect the brake components. Simply reverse the process you used to remove the wheel in order to reinstall it. Be sure to adjust the chain so it fits properly if you’re replacing the back wheel. If the bike has rim or cantilever brakes, simply close them over the new wheel using the lever. If the bike has disc brakes, put the pads back in place and secure them using the clips, springs, or cotter or retaining pin.
First, think about what you need your bike for -- if it's just for a short city commute, in among traffic, then consider a smaller frame that's easy to manoeuvre through cars. The GoCycle G3 (right) is impressively nimble and its electric assistance will help propel you up to 15 mph (24 kph). Better yet, it has built-in lights, automatic gears and you can customise the amount of power the motor provides using a phone app.
As of 2008 a standard class C license, proof of insurance, and registration (annual fee: $9.00) are required for operation of any motorized pedalcycle in Pennsylvania. Additionally, there are strict equipment standards that must be met for operation, including: handlebars, brakes, tires/wheels, electrical systems/lighting, mirrors, speedometer, and horns/warning devices.
Like most electric bikes, the Rad Wagon is also fairly heavy, weighing 72 pounds. The last drawback is that it comes in only one frame size (which I imagine helps to keep costs lower) that fits rider heights between 5 foot 2 inches and 6 foot 2 inches. My 6 foot 4 husband, however, can ride the bike just fine, so there’s some wiggle room to this range.
Since cyclists' legs are most efficient over a narrow range of pedaling speeds, or cadence, a variable gear ratio helps a cyclist to maintain an optimum pedalling speed while covering varied terrain. Some, mainly utility, bicycles use hub gears with between 3 and 14 ratios, but most use the generally more efficient dérailleur system, by which the chain is moved between different cogs called chainrings and sprockets in order to select a ratio. A dérailleur system normally has two dérailleurs, or mechs, one at the front to select the chainring and another at the back to select the sprocket. Most bikes have two or three chainrings, and from 5 to 11 sprockets on the back, with the number of theoretical gears calculated by multiplying front by back. In reality, many gears overlap or require the chain to run diagonally, so the number of usable gears is fewer.
(ii) a vehicle equipped with two or three wheels, foot pedals to permit muscular propulsion, and an independent power source providing a maximum of 2 brake horsepower. If a combustion engine is used, the maximum piston or rotor displacement may not exceed 3.05 cubic inches, 50 centimeters, regardless of the number of chambers in the power source. The power source may not be capable of propelling the device, unassisted, at a speed exceeding 30 miles an hour, 48.28 kilometers an hour, on a level surface. The device must be equipped with a power drive system that functions directly or automatically only and does not require clutching or shifting by the operator after the drive system is engaged.
Power assisted bicycles are classified in two categories in Saskatchewan. An electric assist bicycle is a 2 or 3 wheeled bicycle (sic.: 3 wheeled bicycle) that uses pedals and a motor at the same time only. A power cycle uses either pedals and motor or motor only. Both must have engines with 500 watt power or less, and must not be able exceed 32 km/h (20 mph), i.e., electric motor cuts out at this speed or cycle is unable to go this fast on a level surface. The power cycle has to meet the Federal Motor Vehicle Safety Standards for a power-assisted bicycle. The power cycle requires at least a learner's driving licence (class 7), and all of the other classes 1-5 may operate these also. The electric assist bicycle does not require a licence. Helmets are required for both. Both are treated as bicycles regarding rules of the road. Gas powered or assisted bicycles are classified as motorcycles regardless of engine size or if using pedals plus motor. Stickers identifying the bicycle's compliance with the Federal classification may be required for power cycles by some cities or municipalities. 
It appears Tennessee has not passed any legislation that applies to electric bicycles. Some people think the laws pertaining to a Motorized Bicycle should be used for an electric bicycle. However, a Motorized bicycle would be a gasoline powered device per state law as it is defined as "means a vehicle with two (2) or three (3) wheels, an automatic transmission, and a motor with a cylinder capacity not exceeding fifty cubic centimeters (50cc) which produces no more than two (2) brake horsepower and is capable of propelling the vehicle at a maximum design speed of no more than thirty miles per hour (30 mph) on level ground." 
That being said, It is fun to ride - my 13 year old grandson likes it a lot. I feel it is best used on hard surfaces like sidewalks and hard floors. I received this little scooter 3 days ago and have ridden it in Costco and Sam's club and took it to an art show and sale as well as driving it through hospital halls on the way to and from a meeting.. One has to
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.
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.
Artwork: Hub motors aren't the only way to power electric bicycle wheels. If you've ever watched a mouse scampering around inside an exercise wheel, you might have wondered if you could drive a wheel electrically, in a similar way, with something that pushes against the inside of the rim. A company called GeoOrbital has been developing an ingenious mechanical equivalent that can be used to power conventional bikes—and here's a simplified illustration of how it works. It has a motorized drive roller (red) that presses against the inner rim, powered by a battery pack (orange) that sits snugly inside the wheel. Two guide rollers (blue) mounted on a tensioned framework (green) take the place of the conventional arrangement of spokes. According to GeoOrbital, you can fit one of its wheels to a normal bike in just 60 seconds.
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.
The dwarf ordinary addressed some of these faults by reducing the front wheel diameter and setting the seat further back. This, in turn, required gearing—effected in a variety of ways—to efficiently use pedal power. Having to both pedal and steer via the front wheel remained a problem. Englishman J.K. Starley (nephew of James Starley), J.H. Lawson, and Shergold solved this problem by introducing the chain drive (originated by the unsuccessful "bicyclette" of Englishman Henry Lawson), connecting the frame-mounted cranks to the rear wheel. These models were known as safety bicycles, dwarf safeties, or upright bicycles for their lower seat height and better weight distribution, although without pneumatic tires the ride of the smaller-wheeled bicycle would be much rougher than that of the larger-wheeled variety. Starley's 1885 Rover, manufactured in Coventry is usually described as the first recognizably modern bicycle. Soon the seat tube was added, creating the modern bike's double-triangle diamond frame.
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.
Power-assist: Also known as pedal-assist bikes, these are the bicycle equivalents of hybrid cars: they're designed to be pedaled quite a lot of the time and electrically powered either when you're tired or when you feel like a bit of electric help (when you're going up hill, for example). Unlike full-power bikes, they don't have hub motors; instead, there's a separate electric motor mounted near the rear wheel and driving it either through the gear sprocket or simply by pressing against the rear tire. Where a hub motor is difficult or impossible to pedal without any power (because you're effectively turning it into a generator), power-assist motors turn easily with little or no resistance when you pedal. That gives power-assist bikes much greater range than hub-motor ones (as much as 80–145km or 50–90 miles).
In Norway, e-bikes are classified as ordinary bicycles, according to the Vehicle Regulation (kjøretøyforskriften) § 4-1, 5g. Hence, e-bikes are not registered in the Vehicle Registry, and there is no demand for a license to drive them. Still, there are constraints on the bicycle construction. The maximum nominal motor power output can be no more than 250 watts and the maximum performance speed of the vehicle when the engine is running is 25 km per hour (15 mph). A function that reduces motor power when vehicle speed exceeds 25 km per hour is mandatory. However, if the motor is not running, the e-bike, or any other bike, answer only to the constraints of the ordinary speed limits.