Daniel Dhers, a professional BMX rider from the US, tests Daimler’s Red Dot Design Award winning brandnew smart electric bike and discovers that you can have as much fun with it, as with a regular BMX bike – or maybe even more. The test is set in Barcelona and the viewer experiences the most exciting spots of the city from a professional biker´s perspective.
Here is another picture:
According to a review on treehugger.com it works like:
The rider of the smart ebike decides how much power he wants the electric motor to deliver to support his muscle power by pressing a button on the handlebar. There is a choice of four power levels with the fourth level providing maximum pushing power. Depending on the power level selected and the manner of cycling a battery charge can last for up to 100 kilometres.
With 423 Wh the lithium-ion battery is one of the most powerful batteries in the competitive environment. It has been attractively integrated in the frame of the smart ebike. The portable battery can be charged either at a normal socket or whilst riding, with the latter offering advantages in terms of cost and the environment. The wheel hub motor becomes as a generator when the rider brakes. The braking energy is recuperated, i.e. it is converted into electrical energy and stored in the smart ebike’s lithium-ion battery. (source)