Bersaglieri, Before or early WW I...Given the Mountainouis terrain, I would say WW I, 1915.
Light Coloured Canvas/drill trousers, with Dark Jacket (Blue) is the Pre-War Uniform from about early 1900s; by 1916, Uniforms were changing to all "GrigioVerde" for all Branches of the Italian Army. ( until exhaustion of pre-war Clothing).
Folding Bicycle is typical Bersaglieri model, and TS rifles (early M91 Model). Leather Ammo Pouches are Black, large VV70/87 type...again, using up old Equipment. ( Four Pouches per soldier.).
Doc AV