Thanks for the logical info. About the history, a common result of big wheels were head injuries. Safety Bicycles are early modern bikes.
Originally Posted by
Mikefule
60 t divided by 22 t = 2.72
2.72 x 26 inch wheel diameter = 71 inches. Approx.
That means that the distance you travel per single revolution of the cranks is the same as the distance you would travel with one revolution of the cranks on a penny farthing with a 71 inch wheel.
If you want to know how far you travel per revolution, it's (72 x pi) inches.
The history is that the directly driven wheel (cranks attached to the hub) pre-dated the chain driven bike. The penny farthing was known as the "ordinary bicycle". On an ordinary, the bigger the wheel, the faster you went, for a given cadence. Big wheels were impressive, fast, macho, etc.
When they invented bikes with smaller wheels, geared up, they were called "safety bicycles". In order to market the safety bicycles, they made the comparison directly relevant to the diameter of the equivalent ordinary.
The convention has persisted long after the safety bike has become the new "ordinary".