This is the Freway Buffalo. It’s an ebike. I couldn’t say no to a free ebike to play around on, so we’re gonna have some fun with this thing for sure. It’s not a high end ebike like the Specialized Turbo Levo, but it only costs 1700 bucks whereas the Turbo Levo costs as much as a car. Although it’s marketed as a mountain bike, I’d put it in the commuter category. It’s got a big cushy seat, a really long stem, and those antler things on the handlebars. I’m not obligated to give you guys anything but the truth, so let’s put this thing together and take an objective look at it. First, let’s cruise on over to Freway’s website.
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.

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.

Thanks to clever engineering, the Electric Brompton folds up identically to the non-powered variety. It is heavier than a standard Brompton of course, but quite light by e-bike standards. It has small , suitcase-style additional wheels that come into play once folded up, and the way the weight is balanced means it is quite straightforward to trundle along in that state.  

I tested the Sduro 8.0 towards the end of last year (there's a new range out for 2018) and was surprised by its nimbleness. You expect e-bikes to be less maneuverable than their acoustic predecessors, but, pelting down some bespoke forest paths near Pedal & Spoke in the Surrey hills, I found I completely forgot that there was a box of electronic EPO on my frame. Partly, that's because the battery is cleverly integrated into the frame to decrease drag; mostly, it's because the suspension is soft and the steering nimble, much like a normal mountain bike.

Spec-wise, this thing is tricked out. You’ve got the option to go with  Suntour AION suspension or Fox Float suspension. The drivetrain is Shimano Deore XT. Same with the hydraulic disc brakes. The bike also comes with an ABUS Big Bordo folding lock that is keyed for both the batteries and the lock. Super convenient. There’s also loads of other options within the Delite line. Nuvinci and Rohloff drivetrains, 20mph and 28mph motors, standard and plus tires. You get the idea. Lot to choose from.
A Kalkhoff Pedelec is a lot more than simply bolting a motor onto a great bike. Their electric-assist bicycles utilize a brushless DC motor system that is lightweight, precisely-controlled, efficient, low-maintenance, and reliable. The Panasonic drive system is center drive, meaning that it's designed to be in the middle of the bike for a low center of gravity, stability and an easy integration with the drivetrain. The drive unit is more than just a motor; it also has a torque sensor and controller unit as well - all in the weatherproof casing, surrounding the motor. The torque sensor and the controller senses how hard you're pedaling and adjusts how much assistance the motor gives you through the drive sprocket.
Because e-bikes are capable of greater speeds for longer periods of time than standard bikes, you want extra control. Wider tires provide traction and some bump absorption with little penalty. You also want strong brakes to slow you (and all that extra weight) easily. It's worth looking at the quality of the brakes and investing in bikes with better ones if you can.