After the First World War, the economic situation becomes increasingly precarious. Although Gottschalk still has a good number of orders coming in, company reports comment negatively on supply conditions, production costs and taxation from the mid-1920s onwards. The world is on the brink of technological upheaval, and both large and small businesses are aware of it. Initially, though, it is easier to deplete their reserves. The same goes for Rotax’ major competitor, Fichtel & Sachs. The Schweinfurt-based company reflects on its core market – the bicycle sector – and at the same time identifies motorization of the general public as a future trend. With transformation looming, they put themselves in a more favorable market position with regard to their competition. Little by little, Rotax is weakened, toward the end of the decade Sachs sympathizers already hold posts on the Supervisory Board and Rotax founder Friedrich T. Gottschalk is being persuaded to take a more positive view of a takeover.

Once the company is weakened, Fichtel & Sachs takes it over, and Rotax-Werk AG becomes part of the Sachs universe in 1930. However, Fichtel & Sachs hesitate to institute a full merger. Rotax patents on the one hand and the prominence of the Rotax brand on the other appear to be much more advantageous than full integration. Rotax trades under the umbrella of the Sachs empire and production is gradually switched to Schweinfurt. A move that is perceived as “protection” to begin with increasingly becomes a weakening of Rotax’ activities.