1953 BMW R51 3 Technical Analysis & Specification Breakdown
At the heart of the 1953 BMW R51 3 allround motorcycle, BMW utilizes a 494 cc (30.1 cu in) air-cooled two cylinder boxer, four-stroke layout. In factory specification, peak output is rated at 24.1 HP (17.6 kW) at 5,800 rpm, transferring power to the rear wheel through a 4-speed gearbox and shaft drive (cardan) final drive. With a specific output of 48.8 HP per liter, the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.
On the scales, the R51 3 measures 190 kg (419 lbs) wet (curb), translating to a power-to-weight ratio of 0.13 HP/kg (7.88 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,400 mm (55.1 in) wheelbase engineered for quick, flickable steering geometry. The 17-liter (4.5 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 135 km/h (84 mph).
Within MotoLibrary's BMW archive, this model family spans 4 indexed model years from 1951 to 1954, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
48.8 HP/L
Power-to-Weight
0.13 HP/kg (7.88 kg/HP)
Engine
Displacement494.0 ccm (30.14 cubic inches)
Engine TypeTwo cylinder boxer, four-stroke
Engine DetailsTwo cylinder boxer, four-stroke
Power24.1 HP (17.6 kW)) @ 5800 RPM
Compression6.3:1
Bore x Stroke68.0 x 68.0 mm (2.7 x 2.7 inches)
Fuel SystemCarburettor. 22mm
Fuel ControlOverhead Valves (OHV)
LubricationWet sump
CoolingAir
Transmission
Gearbox4-speed
Final DriveShaft drive (cardan) (final drive)
ClutchDry-single plate-cable operated
Performance
Top Speed135.0 km/h (83.9 mph)
Chassis
Frame TypeSteel single cradle
Front SuspensionCartridge
Rear SuspensionTelscopic
Wheelbase1400 mm (55.1 inches)
Wheels & Brakes
Front Tyre3.50-19.00
Rear Tyre3.50-19.00
Front BrakesExpanding brake (drum brake). Duplex full hub
Front Brake Ø200 mm (7.9 inches)
Rear BrakesExpanding brake (drum brake). Simplex full hub
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.