Rihosek attended the middle school at Olmütz and later studied mechanical engineering at the Vienna Technical University.
From 1897 he worked in the Department for Locomotive and Coach Construction headed by Karl Gölsdorf within the Imperial Royal Railway Ministry.
The First World War and its consequences placed heavy demands on Rihosek, because the lack of materials led to problems in the manufacture of vehicles.
Following the dividing up of the locomotive fleet to the new states formed from the breakup of the Austro-Hungarian empire, replacements had to be procured.
He carried out this work in conjunction with the firm of Gebrüder Hardy A.G., on whose board he sat until his death.