Reference: Wikipedia "Bicycle Infantry" & "Folding Bicycles".

In France, several experimental bicycle units were created, starting in 1886.[4] They developed folding bicycles, that could be collapsed and carried slung across the backs of their riders, from an early date. By 1900 each French line infantry and chasseur battalion had a cyclist detachment, intended for skirmishing, scouting and dispatch carrying. In the years prior to World War I the availability of an extensive network of paved or gravel roads in western Europe made military cyclists appear a feasible alternative to horse mounted troops; on the grounds of economy, simplicity of training, relative silence when on the move and ease of logistical support.