But most end up being far too inconvenient to ever use in a city. They are often too expensive, difficult to ride, and too big or heavy to realistically carry around with you.

It seemed as if finding a bike that is small enough to be portable, and lightweight enough to be carried around was unachievable.

But that's where the aptly named the 'impossible' bike comes in. 

This lightweight bike can be easily folded to fit inside any normal backpack, weighs less than 11 pounds and is a mere 17 inches tall when folded, according to CNET — plus, it's electric.

The designers of the bike realized that the only way to accomplish the challenge of making a bike completely portable was to build an entirely new bike design — one where the frame of the bike was built around circles instead of lines.

So, after three years of development, they created a bike that unfolds through a series of circles in four simple steps: