BMW's move into motorcycles was, in part, a forced one: after the First World War, the Treaty of Versailles barred the company from building aircraft engines, pushing it toward other machinery. Engineer Max Friz, who had joined BMW in 1917, designed the company's first true motorcycle, the R32, unveiled at the 1923 Berlin Motor Show. The R32 introduced the transversely-mounted flat-twin "boxer" engine and shaft final drive - a configuration BMW used on every motorcycle it built for the next seven decades and still offers today. That combination of unconventional engine layout and shaft drive, rather than the chain-driven inline engines common elsewhere, became BMW Motorrad's defining engineering signature, and the brand has built its reputation since on touring and adventure motorcycles engineered with the same precision as its cars.