Budd–Michelin rubber-tired rail cars remained obscure in comparison with other competitors for the title, such as the "Pioneer Zephyr" and Union Pacific's M-10000. Rubber-tired rail cars achieved greater success in France, and similar rubber-tired subway cars have been adopted in Canada and Mexico as well as on numerous systems in Europe. During the 1920s, the American Budd Company, at the time a relatively obscure auto-frame supplier, developed an extensive working relationship with the French firm Michelin, which was best known for its tires. In 1929, Michelin built its first rail car, and by 1932 nine of its cars were in operating service, all of
First World War glass–rubber exchange supply of natural rubber it was unable to produce the quantities of communications cables, tyres and fan belts required for its operations. Germany had attempted to manufacture synthetic rubber but at this early stage quantities produced were low and the product was of poor quality. Britain and France, by contrast, had access to large quantities of natural rubber from their African and Asian colonies. By early 1915 the German army was so desperate for tyres that it was considering running its supply trucks on steel tyres, which would have severely damaged road surfaces. An agent from the British Ministry of