Sure, you train hard and eat right, but there’s just one thing missing—an edge. The Amira gives you two. First, there’s the performance edge you get from its FACT carbon frame and tapered head tube. The combination results in responsive handling and true get-up-and-go accelerations. Then comes the psychological edge. The feeling that, when teamed up with a lightweight, high-performance machine, there’s no limit to what you can achieve together.
It is important to note that the less power you use while riding your e-bike, the longer the battery will last, makes sense right? All of the pedal-assist drive units we tested also have smartphone apps that can be used to customize your support settings, and such changes may allow for more or less range on your electric mountain bike. Specialized's Mission Control app has a feature that lets you set a predetermined route, and the app then regulates the motor's support to ensure power lasts to finish your ride.
E-bikes use rechargeable batteries and the lighter ones can travel up to 25 to 32 km/h (16 to 20 mph), depending on local laws, while the more high-powered varieties can often do in excess of 45 km/h (28 mph). In some markets, such as Germany as of 2013, they are gaining in popularity and taking some market share away from conventional bicycles,[1] while in others, such as China as of 2010, they are replacing fossil fuel-powered mopeds and small motorcycles.[2][3]
Assembly was pretty simple and straightforward, there are some videos online explaining it. Definitely important to know how to switch it on, though -- pressing the "M" button for two seconds with the key in the "on" position. Despite being a heavy bike, it's very quick and nimble. I ride about 15 miles per day and was able to get two trips out of it before charging, riding fast. My only complaints are the squeaky brakes, and the front fender. Said fender is a bit too close to the tire on the front wheel and doesn't mount very securely, so it kept making very loud noises as it would catch the tire whenever I went over a bump or had to brake hard. I just took it off for the time being.
Electric bikes are a green alternative to driving a vehicle. Studies carried out in several towns and cities show that the average car speed in rush hour traffic can dip as low as 18 to 20 mph. Electric bike speed can be as high as 15 mph. With an electric bike, you can reduce pollution, improve fitness, and still arrive at the same time as your car-bound colleagues.

Time to give some love to my dudes and dudettes over at Bulls bikes. The Bulls E-Stream Evo AM 4 27.5+ (phew, out of breath after saying that one) is an incredible electric bike for the price point. I was going to put the step down from this bike on the list, (2018 Bulls E-Stream Evo AM 3 27.5+) but I realized that this bike is only $400 dollars more. The upgrades you get for that 400 bucks are pretty remarkable.

The Brose motor puts out 250 watts nominally, and can peak up to a max of 460 watts. That’s around half what the 2016 Specialized Turbo S road bike we tested last year develops, but that bike’s much-larger motor sits in the rear hub, which would massively compromise performance on a full-suspension mountain bike like this one. Spend up to the Expert or S-Works spec Turbo Levo and you get a motor that can peak up to 530 watts. 
By 1898 a rear-wheel drive electric bicycle, which used a driving belt along the outside edge of the wheel, was patented by Mathew J. Steffens. Also, the 1899 U.S. Patent 627,066 by John Schnepf depicted a rear-wheel friction “roller-wheel” style drive electric bicycle.[7] Schnepf's invention was later re-examined and expanded in 1969 by G.A. Wood Jr. with his U.S. Patent 3,431,994. Wood’s device used 4 fractional horsepower motors; connected through a series of gears.[8]