Comment by bambax

> A "bicycle" that can accelerate without the need to pedal at all is an electric motorcycle

Most pedal-assist-only ebikes can run without you pedaling (and without a throttle either). You just need to pedal fast at first, and then take your feet off the pedals. (You can rest them at the center of the frame for example.)

Usually, if there is some friction in the system (but not too much) the pedals will keep on turning, making the bike think actual pedaling is going on. And then the system is self-sustaining (battery permitting, of course).

It's quite funny to do; not very practical, or elegant, but fun.