So there you go - climate change (even temporary) helped create the modern bicycle.
Some hobbyists have converted modern bicycles to use retro-direct gearing.
De Sivrac's "wooden horse" was the earliest prototype of the modern bicycle.
This is the case for most modern bicycles.
Many modern bicycles use what is called a "cartridge" bottom bracket instead.
Recently, due to advancements in internal gear technology, a small number of modern shaft-driven bicycles have been introduced.
The practice of measuring how far and fast a bicycle travels emerged alongside the modern bicycle in the 1860's.
Even though modern bicycles use a similar design, the term is rarely used today, and may be considered obsolete.
Later historians began to use the term in a more restricted way, for the design that was a direct ancestor to most modern bicycles.
This was the ancestor of the modern bicycle and a step toward mechanized personal transport.