I'm not associated with the company but find this concept interesting. From the website: The mechanical crank drive system for bicycles was invented around 150

I'm not associated with the company but find this concept interesting. From the website: The mechanical crank drive system for bicycles was invented around 150 years ago and has hardly been improved since. We took the drive system further and developed the cyfly Easy Cycling Technology Kind of funny (but not that surprising) is that there seems to be an automotive company involved in the research.