In addition the specific wording of the law may or may not prohibit the use of a "mid-drive" or "crank-drive" motor set-up where the motor drives the rear wheel of the bicycle through the existing chain drive of a bicycle that has multiple gears depending on several points of interpretation of the law. Specifically the interpretation of the wording, "does not require clutching or shifting by the operator after the drive system is engaged". A "mid-drive" or "crank-drive" motor set-up on an electric bicycle does indeed allow the operator to change gears in the power drive system between the motor and the rear wheel of the bicycle. Whether or not such a mechanism which allows the operator to change gears satisfies the wording that requires the operator to change gears is a matter of legal interpretation by the courts. Just as "shall issue" and "may issue" (as in laws governing the issuing licenses) in application of the law have two different meanings (in the first case if you meet the requirements they have to give you the license and in the second they don't have to if they decide not to even if you meet the requirements for the license) whether or not "does not require shifting" outlaws electric bicycles where shifting is possible but is not necessarily required is a matter of interpretation. Thus the legality of electric bicycles equipped with a "mid-drive" or "crank-drive" motor set-up in the U.S. state of Montana is not clearly defined.
In the 1890s, electric bicycles were documented within various U.S. patents. For example, on 31 December 1895, Ogden Bolton Jr. was granted U.S. Patent 552,271 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-volt battery.
"Electric-assisted bicycle" means a bicycle with two or three wheels, a saddle, fully operative pedals for human propulsion, and an electric motor. The electric-assisted bicycle's electric motor must have a power output of no more than one thousand watts, be incapable of propelling the device at a speed of more than twenty miles per hour on level ground, and be incapable of further increasing the speed of the device when human power alone is used to propel the device beyond twenty miles per hour.
The body is made from light and durable aluminum. The handlebar comes with simple controls to let you accelerate, brake, monitor battery life, operate headlights and of course…sound the horn. There’s even an USB point that will let you charge your iPhone or Android on the go. The bike can reach a top speed of 10mph. Feel the wind in your hair as you zoom up and down hills and past all that city traffic…
Government regulation is written and administered with a broad, dull, painful axe. Regulations do not mix well with independent, maverick, DIY programs either. Vehicle regulations get started when there is either a visible tragedy, or a rising conflict with the status quo (like the SFO scooters program). The ebike community cannot afford a deadly accident especially if it involves others and the ebike or ebike rider are at fault. The Ebike community is up against a tough status quo that consists of pedestrians, motor vehicle traffic, the large well-funded and battle tested regular bicycle community, and the environment (especially for MTB riding and off-road use).
While the first functional battery was developed in the year 1800 by Italian physicist Alessandro Volta, a practical battery would not be seen for several decades yet. By the end of the 19th century, practical and portable batteries were more widely available, this finally freeing the electric motor to be used in a wide new array of applications. It might come as a surprise, but the electric motor, battery, and a bicycle were first paired as far back as the 1890s. It would be approximately 100 years later that electric bicycle development finally entered the mainstream, but the technology and concept behind the electric bike were all in place generations ago.
E-bikes are zero-emissions vehicles, as they emit no combustion by-products. However, 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, e-bikes are claimed to have a significantly lower environmental impact than conventional automobiles, and are generally seen as environmentally desirable in an urban environment.
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. 
In summary, federal law trumps all States’ laws. That is true with bicycle law, too. States cannot constitutionally pass legislation that reduces or eliminates Federal laws, they can only pass legislation that enacts additional (tighter) restrictions on its people. States can’t define an ebike a bicycle if greater than 750W/20mph, nor can they define an ebike a motor vehicle if less than the Federal Government’s limit of 750 Watts and a top electric-powered speed of 20 MPH.3This is the Federal definition of a low speed electric bike, which equates it to a bicycle.
E-bikes mostly use motors and battery options from a few major suppliers: Bosch, Yamaha, Shimano, and Brose. A few other brands exist, but are less reliable or powerful. Some, like the Yamaha system, have more torque, and others, like Bosch’s Active Line, are nearly silent. But, generally, all four make good options. Look for motor output (in torque), which will give you an idea of total power. Just like car engines, more torque equals more power off the line and more boost to your pedaling. But watt hours (Wh) is perhaps a more important figure to use—it takes into account battery output and life to give a more accurate reflection of power (higher Wh equals bigger range).
The time or distance an electric bike battery will run between chargings is impossible to judge with much accuracy. There are too many variables: terrain, speed, rider weight, bike load (shopping, kids, luggage), and more. However, we can make a few generalizations about an e-bike’s recharge time and overall working life. These generalizations should be used for comparison purposes only.
And let’s not forget the economic advantages of owning an e-bike. The annual cost of running a new family car is, on average, about $9,000 per year. Running an electric bike costs around $400 per year. And while filling a gas tank costs around $30, recharging an electric bike battery costs only about 50 cents. A tank of gas may get you further, but not 60 times further!