BMW 1938 R 61 600 cc side valve horizontally opposed twin with shaft drive frame# P1622 engine#603813
In the late thirties BMWs were sold in considerable numbers, in spite of their high prices.
The make had built up an excellent reputation for quality and luxury: from 1938 on all BMWs had both front and rear springing, a feature which was very uncommon for most other makes.
From 1938 till the war stopped production of civilian bikes all BMW twins shared a common frame and cycle parts.
All engines were interchangeable and shared the same transmission. Only the rear axle ratios were different.
The 600 cc engine with bore and stroke of 70×78 mm, has a compression ratio of 5.7 : 1 and a power output of 18 HP @ 4800 rpm which gives a maximum speed of about 115 km/hour.
Fuel tank capacity is 14 litres. Between 1938 and 1941 some 13,000 R 61’s were built.