BMW 1938 R51 Sport 494 cc 2 cyl OHV 3503

BMW 1938 R51 Sport 494 cc OHV horizontally opposed twin frame # 511303 engine # 505591

In the late thirties BMWs are sold in considerable numbers, in spite of their high prices; in the UK a 1938 BMW R51 costs £123, while a Triumph Speed Twin can be had for less than £77. The make has built up an excellent reputation for quality and luxury: from 1938 on all BMW twins have both front and rear springing, a feature which is at the time very uncommon for most other makes. During 1937 the firm gets excellent publicity; five Grand Prix races are won and Ernst Henne sets the absolute world speed record for motorcycles at 279.503 km/h! This astounding record will hold for 14 years.

From 1938 till the war stops production of civilian bikes all BMW twins share a common frame and cycle parts. All engines are interchangeable and share the same transmission, only the rear axle ratios are different. The R51 has many features in common with its predecessor, the R5. That boasts such features as a double cradle arc-welded frame made of oval tubes, hydraulically dampened telescopic forks, foot-operated gearchange, a new type of engine with two camshafts, hairpin valve springs and quickly detachable and interchangeable wheels. New for the R51 is the plunger rear springing. Power delivered is 24 hp @ 5,600 rpm, good for a top speed of around 140 km/h. Between 1938 and 1940 no more than 3775 R51 machines are built.
This tidy and well-restored R51 would be an excellent choice for the enthusiast who likes to ride a pre-war machine with post-war specifications and comfort.

Video: https://youtu.be/6GFl1hCbph8