You turn it on by pressing the green button on the battery once for low power and twice for high, although to be honest, there is not a lot of difference between them. After that, you just pedal. There are no gears, no chain to muck up your trousers (a motorbike-style carbon fibre belt is used instead) and not that much difference in feeling compared to riding a normal bike.
Certainly not for the entry-level e-bike buyer, those who need to strap cargo to their back now have a new option with the Riese & Muller Load option, with full cargo space on the front of the bike. While over $6,000, the full-suspension bike has adjustability to allow for differing loads. Safety features include LED headlights and premium components abound.
What we especially love is how quiet this e bicycle is. If you’re riding down the street or through the park, the gentle hum of the motor is unnoticeable. This is because it’s hidden by the sound of your smooth pedaling. If you’re not into flashy gadgets, any ordinary person would assume you’re riding a conventional peddle bike. This is a great commuter bike.
Sometimes space comes at the most premium of commodities and the Tern Vektron offers a space-saving folding option. At about $3,400, the sturdy folding joints include a magnet and rubber strap to keep the bike folded. The quick-release pedals (wheels release too) help with storage of a bike that doesn’t give up power with a 20-mph speed that can range over 60 miles. But the best part is placing two in the trunk of a car.
I picked this bike because it’s definitely one of the lowest cost 28mph bikes out there that is still high quality. Magura MT4 hydraulic disc brakes keep you good and safe. The geometry provides a comfortable ride. Personally, I don’t always think a suspension fork is totally necessary since they are less efficient. If you’ve got a pretty smooth road to ride this is a great option.
As a counterbalance to the cute utilitarian bikes above, the Specialized Turbo Levo FSR Comp is a big, bad, and burly mountain bike. With 27.5-inch wheels, massive 2.8-inch tires, 150mm of travel in the front and 135mm of travel in the rear this bike is made to shred. The Specialized 1.3 Rx Trail-Tuned motor is designed specifically for off-road riding and features a double freehweel design that disengages the gear box at top speed to reduce friction while ripping downhill. The low center of gravity and stout parts make this one a relatively nimble handler that is ready for the rowdiest downhills.
"Bargain Buys" Most electric bikes priced less than $600 at big box retailers and on-line are aimed at the kid/teen/toy market. They generally lack the performance and durability that people want and expect. Also, parts and service can be problematic with both big box retailers and on-line vendors. We urge you to invest in a quality e-bike, preferably from a local dealer, that will serve you (and others) for many years. Remember, if it's poorly constructed and you can't get repair parts, it will likely become land-fill material. Save, beg, or borrow the money to get a quality bike or kit.
Controllers for brushless motors: E-bikes require high initial torque and therefore models that use brushless motors typically have Hall sensor commutation for speed and angle measurement. An electronic controller provides assistance as a function of the sensor inputs, the vehicle speed and the required force. The controllers generally allow input by means of potentiometer or Hall Effect twist grip (or thumb-operated lever throttle), closed-loop speed control for precise speed regulation, protection logic for over-voltage, over-current and thermal protection. Bikes with a pedal assist function typically have a disc on the crank shaft featuring a ring of magnets coupled with a Hall sensor giving rise to a series of pulses, the frequency of which is proportional to pedaling speed. The controller uses pulse width modulation to regulate the power to the motor. Sometimes support is provided for regenerative braking but infrequent braking and the low mass of bicycles limits recovered energy. An implementation is described in an application note for a 200 W, 24 V Brushless DC (BLDC) motor.