"What? That’s an e-bike?" tended to be the first reaction we got to the Cooper. There’s very little (bar the oversized rear hub) that says e-bike on the ‘E’ at all. Cooper have taken a traditional gauge Reynolds 520 steel frame and dressed it with a practical mix of (surprisingly effective) Tektro caliper brakes, Sturmey Archer crank and chainring and topped it off with Brooks Cambium C17 All-weather saddle. They’ve then paired it with a Zehus All-in -One electric hub, so there’s no leads, no external battery, not even an on and off switch.
An electric bicycle, also known as an e-bike, powerbike or booster bike, is a bicycle with an integrated electric motor which can be used for propulsion. Many kinds of e-bikes are available worldwide, from e-bikes that only have a small motor to assist the rider's pedal-power (i.e., pedelecs) to somewhat more powerful e-bikes which tend closer to moped-style functionality: all, however, retain the ability to be pedalled by the rider and are therefore not electric motorcycles.
I wanted to include an electric bike that would be ideal for off-road and trail bike touring, and I think the Bulls E-Stream Evo 3 27.5 Plus is it. This hardtail mountain bike would be perfect for bike tourists going out on the trails for a few days. You could conceivably go for a few days without needing to recharge the Brose 650 watt hour battery, so even if your camping in the wilderness with nowhere to recharge for 60-100 miles you would likely be fine on battery life.
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.
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.[43]
It’s impressive just how traditional a finish they’ve achieved for a pedal-assist bike, especially considering the motor uses Kinetic Energy Recovery to charge itself (like F1 Cars). Firing up the motor is achieved by back-pedaling three times (while travelling over 8mph). It’s a neat idea, and a clever way of doing away with those cables and switches, but in reality it’s fiddly. Riding in the city we occasionally felt ridiculous on a busy street pedaling backward rather than forward to kick off the assist. It’s also a chore getting the bike to speed and going through the motion to activate in tight spaces such as underground garages or on an incline.
For many bikes, battery range is more important that total power (because they're all pretty powerful). You want a bike that delivers a range long enough for your rides at the power levels you want. Most e-bikes will have three to five levels of assist kicking in anywhere from 25 percent of you pedal power to 200 percent boost. Consider how fast the battery takes to recharge, especially if you'll be using your bike for long commutes.
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