The suspension was also derived in large part from existing designs but used torsion bars rather than coils as the springing medium. Along with a four-speed manual ZF gearbox mounted remotely from the engine and controlled by a lever on the steering column, these parts were installed on a simple, rugged chassis made up of longitudinal box-sections tied together by large transverse tubes.
The steel semi-unit body—which bolted to the chassis even though most automakers had already adopted unit construction—was designed in-house under the direction of Wilhelm Meyerhuber. The first three prototype bodies were supplied by Reutter, but the manufacture of series production 501 sheet metal was initially entrusted to the Baur firm in Stuttgart. Baur continued to supply finished shells through 1955, when BMW started making these parts in-house, and it would also build a series of coupe and cabriolet bodies for the 501 and 502.
By specifying light alloy for bumpers, trim, window frames and more, BMW kept the 501’s curb weight to roughly 3,000 pounds. Though reasonably compact (measuring exactly the same 186 inches stem to stern as the contemporary Mercedes-Benz 220), the 501 looked massive thanks to its voluptuously curved shape. Well decorated with bright trim and lights set into plated housings, it earned the nickname “Baroque Angel” in Germany. Had he painted cars instead of women, Peter Paul Rubens would have delighted in the 501’s form. Odd from some angles, striking from most, it was, and remains, distinctive.
Extroverted as it was, the 501’s design was also practical. The four doors—with the rear pair hinged at the back—allowed easy access to the roomy cabin, and the humped rear deck lid covered a generous cargo space. Glass area was unusually large for a car of the early 1950s, as well, affording almost unobstructed views from the driver and passenger seats.
Oddly enough, the interior displayed the most obviously low-rent aspects of the 501. Simple, painted-metal dashboards weren’t all that unusual in the early 1950s, but this one was remarkably plain for a high-class machine. The seats were covered in cloth, while the front floorboards were topped by rubber floormats. Rear-seat passengers rested their feet on what one British magazine unappetizingly called “hair-cloth” carpet. No power assists were provided unless the optional Becker radio was fitted, in which case its antenna was raised and lowered electrically.
Eventually, an expensive export
When the prototype 501s made their debut at the 1951 Frankfurt Motor Show, reactions were apparently positive, but they were not accompanied by a flood of orders. Still, production got underway in 1952, and the company sold enough 501s to subject the design to continued development. In 1954, the “plain” 501 was superseded by the 501A, with its engine massaged to produce 72 hp, and the identical but even more Spartan 501B.