The Polish army wanted a sturdy motorcycle with a sidecar, comfortable like a Harley-Davidson and with a great engine, like an Indian. The army’s requirements were concretized in May 1928.
Author: Adam Jońca
This is partial text from the full article (usually with photos) at https://armorama.com/list/single-vehicle-no--09---polish-heavy-military-motorcycle-p-z-inz--m111-sokol-1000