The other thing to consider is that this is a Kickstarter project, so you aren’t directly purchasing from the company, but rather “backing the project” in exchange for a bike. Technically, Stark Drive, or any Kickstarter creator, could cut and run with the money, leaving their backers without legal recourse. In this case though, Stark Drive has already run a successful crowdfunding campaign for their previous bike and demonstrated their ability to deliver, so this is probably at least somewhat safer than a brand new Kickstarter start-up.
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.
Look at Bulls giving you options! Very similar bike, but with the Bosch Performance Speed motor. Why did I include if it’s so similar? Because I think Bulls has build super interesting commuters. They set you up with a adjustable stem so you can literally be as upright as you want, if you’re a posture freak. Underrated part of this bike: water bottle boss placement. Call me crazy, but it’s little touches like these that tip the scales on commuting bikes for me. It isn’t always easy to find places to put cages on e-bikes.
The first step in deciding which Electric Bike is for you is to determine the right style of bike. We have a full range of styles, including, Mountain Electric Bikes, Comfort E-bikes, Commuting E-bikes, Fat Tire Ebikes and even folding bikes. From their, you'll choose the motor size. We offer motor sizes from 100 Watts all the way up to 6000 Watts!
As electric bike options continue to expand, more brands are integrating the battery more seamlessly. That makes them look sleeker (and more like a real bike). Batteries are expensive, so make sure there's a good way lock the battery to your bike if you'll be keeping it outside. Overall weight is important. Some battery and motors can add 15 pounds or more to the bike. With assist, you won't feel that much when you're riding, but you will if you have to carry your bike up stairs or lift it onto a bike rack.