R 51 SS: Michael Nelson
1938 BMW R 51 SS #506218
494cc M254/1 Boxer Twin >24 hp @ 5,600 rpm
In 1938, the R 51 added rear suspension to Rudolf Schleicher’s revolutionary R 5 of 1936 which had introduced an arc-welded steel tube frame, foot-operated shifter, and an overhead valve boxer twin. The R 51 seen here is a customer-racing SuperSport model, with a race-prepped engine, racing exhaust, and close-ratio four-speed gearbox, plus the optional larger tank. It was sold when new to English privateer Tim Reid, who joined the BMW factory team at the Isle of Man in 1939 but DNF’d. His family kept the R 51 SS in original, running condition for 60 years before selling it to California enthusiast Michael Nelson.