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.
Over the last few years, I’ve taken my love of the outdoors, hiking, skiing, trekking and exploring to the next level by starting this site. I started a bike shop in Denver, CO, and have seen amazing growth over the last few years. Getting paid to do what I love has been a dream come true for me. That’s also what led me to start In my shop, I spend a large amount of time helping people find the perfect bike for them and the style of biking they’re going to be doing. It only made sense that I expanded my reach and got online, making it possible for me to help people all over the world. If biking and staying fit is your priority, too, you’ve come to the right place.

When I began testing the Rad Power bike, I wasn’t sure if it would ride like a bakfiets or more like your standard bike. Hundreds of miles later, the RadWagon’s biggest strength is how well it handles. If you aren’t riding with kids, you almost never notice the weight of the cargo area behind you and pedaling is made easy and efficient thanks to a 750W direct drive hub motor and smooth acceleration.

Today, China is the world's leading producer of electric bicycles. According to the data of the China Bicycle Association, a government-chartered industry group, in 2004 China's manufacturers sold 7.5 million electric bicycles nationwide, which was almost twice the year 2003 sales;[8] domestic sales reached 10 million in 2005, and 16 to 18 million in 2006.[9] By 2007, electric bicycles were thought to make up 10 to 20 percent of all two-wheeled vehicles on the streets of many major cities.[9] A typical unit requires 8 hours to charge the battery, which provides the range of 25–30 miles (40–50 km),[9] at the speed of around 20 km/h.[8]

Controllers for brushed motors: Brushed motors are also used in e-bikes but are becoming less common due to their intrinsic lower efficiency. Controllers for brushed motors however are much simpler and cheaper due to the fact they don't require hall sensor feedback and are typically designed to be open-loop controllers. Some controllers can handle multiple voltages.

E-bikes can also provide a source of exercise for individuals who have trouble exercising for an extended time (due to injury or excessive weight, for example) as the bike can allow the rider to take short breaks from pedaling and also provide confidence to the rider that they'll be able to complete the selected path without becoming too fatigued[58] or without having forced their knee joints too hard (people who need to use their knee joints without wearing them out unnecessarily may in some electric bikes adjust the level of motor assistance according to the terrain). A University of Tennessee study provides evidence that energy expenditure (EE) and oxygen consumption (VO2) for e-bikes are 24% lower than that for conventional bicycles, and 64% lower than for walking. Further, the study notes that the difference between e-bikes and bicycles are most pronounced on the uphill segments.[59] Reaching VO2 Max, can really help your body as a whole[60]. Professor Janet Lord of Birmingham University in the UK published a study that looked at older cyclists, ““The study looked at muscle mass, blood cholesterol, their VO2 Max, lung function, and in many of those measures we found they didn’t age! No loss of muscle, their bones were a little thin (but nothing like the general population), their blood pressure didn’t go up.[61]
Speaking of which, if you're used to non-electric cycles, be aware that e-bikes are heavy and capped at 25kph or 15.5mph. In many cases, that means the bike starts to feel like its actively fighting against you, if you try to push the speed higher than that by pedalling. That's especially true with heavier bikes, for obvious reasons, and can take a while to get used to. 
It’s a topic that many eMTBers are interested in: fast charging. What has long been a reality with electric cars is now also being partly improved for ebikes with high amperage chargers. Bosch has presented a 6A charger this year that can charge a 500 Wh battery in 3 hours, more than a third faster than the standard charger. The new benchmark next year, however, will probably be the 10A charger presented by Haibike and BMZ. It is claimed to be capable of charging a 630 Wh battery in just 1.5 hours. 

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.