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BMW Motorcycles

BMW R5 500cc 1936-1937

Production years: 1936-1937
Power: 24 CV at 5800 rpm
Capacity: 494cc
Engine: OHV HO twin
Transmission: Cardan
Maximum speed: 135 Km/h
Units produced: 2,652
Weight: 165 Kg

At the 1936 Berlin Motor Show BMW introduced a completely new model with considerably more power than its predecessors, achieved by employing two chain-driven camshafts which allowed much shorter pushrods to the overhead valves, with a significant increase in maximum RPM as a result.

It also used hairpin valve springs from BMW's racing machines rather than the traditional coil-type valve springs, and had more advantageous valve angles.

The newly designed engine used a tunnel-type crankcase similar to the R2 single; following the introduction of the R5, this style of crankcase became standard on all air-cooled BMW motorcycle engines.

The R5 marked a departure from the the heavy pressed-metal frame design in favour of a strengthened version of the tubular frames employed on BMW racers. The sophisticated hydraulic forks again appeared, now featuring a control for adjusting damping characteristics. The R5 still had no rear suspension, but featured the sprung saddle from the R7 concept bike. The new design retained a vestigial hand-shift lever protruding from the transmission case. Although this lever was essentially useless for anything other than finding neutral when coasting to a stop, it survived until 1955.

This was by far the most advanced motorcycle BMW had ever produced, and is considered by many to be among the finest road-going machines built during the 1930s.

The R5 engine was also used after the war, with minor changes, in the model designated R-51/2.

HO Twin

Horizontally Opposed Twin

Examples include BMW, Zundapp and Douglas HO Twins have conrods running on a common crank, with one on the exhaust stroke and the other on inlet.
Cardan

Shaft Drive

Examples include BMW, Zundapp and Velocette LE Cardan drive eliminates chain and associated mess and maintenance. Often referred to as a "diff", the final drive unit consists of bevel crown and pinion gears.

Source: desmodromics.co.nz via archive.org, et al

  • BMW 1936 Models