What key distinction separates the general term 'bicycle' from Drais's initial invention?

Answer

Two wheels of equal size and a chain drive

The term 'bicycle' generally refers to a machine incorporating two wheels of equal size and a chain drive, features that were absent in Drais’s original pedal-less concept.

What key distinction separates the general term 'bicycle' from Drais's initial invention?
inventordesignmachinepedalbicycle