I’m struck by how modern those bicycles look
This source says 1914:
Which makes sense as they looks like mostly older soldiers.
So it’s a toss if this is pre or post WW1 being declared. Judging by the smile of 4th from the left and the last guy, I’d say this is after war got declared.
This is probably after WW1 being declared. At the beginning of the war the French uniform was red pants and navy coat.
They changed it after few months when they realized that red pants was just turning the soldiers into very visible targets.
Are we not trusting the text on the picture? It says June 1916
For the front cover, but this is the rear cover and there’s no date for that.
Ah got it!
[off topic]
Fin de cycle, by Howard Waldrop.
Speculative fiction about the French Army’s bicycle unit.
https://www.academia.edu/1387773/Fin_de_cycle_romance_and_the_real_inThe_wheels_of_chance