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.
It will be of little surprise to learn that the Hanebrink all-terrain vehicle was designed by six time Mountain Bike national class champion and former U.S. National Team member Dan Hanebrink. It's based on 1993's Extreme Terrain fat tire pedal bike and is made to order at the Fortune Hanebrink workshop at Big Bear Lake, California. Echoing the philosophy of many electric assist bicycle makers, Hanebrink says: "We are not trying to replace standard bicycles, we want to replace cars and trucks."
The Moterra is Cannondale’s biggest and baddest e-mtb and just looking at this thing you can see that it’s built to withstand some wicked downhills and big drops. With 130mm of front and rear travel, paired up with 27.5-inch wheels and trail-grabbing 2.8-inch tires, along with a KS LEV Integra Dropper Post make this pedal-assist mountain bike a great option if you want to climb farther to shred longer, but don’t want to lug your bike uphill for ages. The 250w motor, placed slightly farther forward than most other bikes to optimize weight distribution and handling, will give you a nice boost so you can enjoy the ride up and not be too gassed when you get to the top. After all, it’s all about the ride down, right?
Electric bikes are here in a big way. Liberated from some of the normal constraints of standard bike design like weight and gearing, e-bike design has exploded; if you can imagine it, someone has built it. From cargo bikes to city bikes, messenger bikes to mountain bikes, road bikes, and even beach cruisers, there is something for everyone. The beauty of e-bikes is they make the joy of cycling accessible to so many people in so many ways.