W. F. Grew, The Cycle Industry (1921)
“ We have now arrived at the stage when a high bicycle was regarded as dangerous, and, if the front wheel were too small, it detracted from the rider’s speed owing to the shorter distance covered by each turn of the wheel. What was the next move? The engineer’s mind turned towards a method of gearing by cogs or chains, by which one turn of the crank axle would cause the driven wheel to turn more than once. That is where we get our method of describing the ratio of gearing between the crank and the wheel of a modern safety bicycle. ”
