BMW 1938 R51 Sport 494 cc overhead valve horizontally opposed twin frame # 505238 engine # 501136
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 BMWs have both front and rear springing, a feature which is at the time very uncommon for most other makes. 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.
The machine on offer has been in the former owner’s possession for almost 15 years. She has been kept in a dehumidified garage and has been used sparsely for local runs and vintage rallies. Both wheels have been rebuilt and new tyres fitted. Two new old stock carburettors have been sourced and fitted, and the mudguards have been professionally resprayed. Judging from the engine number the power source originates from a 1937 R5 model. The Beemer is a good runner and comes with photostat copies of the handbook in English and German. This R51 would be an excellent choice for the enthusiast who likes to ride a pre-war machine with post war specifications and comfort.