1952 BMW R25 2 Technical Analysis & Specification Breakdown
At the heart of the 1952 BMW R25 2 allround motorcycle, BMW utilizes a 247 cc (15.1 cu in) air-cooled single cylinder, four-stroke layout. In factory specification, peak output is rated at 12 HP (8.7 kW) at 5,600 rpm, transferring power to the rear wheel through a 4-speed gearbox and shaft drive (cardan) final drive. With a specific output of 48.6 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 R25 2 measures 140 kg (309 lbs) wet (curb), translating to a power-to-weight ratio of 0.09 HP/kg (11.67 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,335 mm (52.6 in) wheelbase engineered for quick, flickable steering geometry. The 12-liter (3.2 US gal) fuel tank paired with a rated consumption of 2.9 L/100 km provides an estimated theoretical range of roughly 414 km (257 miles) between fill-ups, while factory top speed is listed at 80 km/h (50 mph).
Within MotoLibrary's BMW archive, this model family spans 3 indexed model years from 1951 to 1953, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
48.6 HP/L
Power-to-Weight
0.09 HP/kg (11.67 kg/HP)
Theoretical Range
~414 km (257 mi)
Engine
Displacement247.0 ccm (15.07 cubic inches)
Engine TypeSingle cylinder, four-stroke
Engine DetailsSingle cylinder, four-stroke
Power12.0 HP (8.7 kW)) @ 5600 RPM
Compression6.5:1
Bore x Stroke68.0 x 68.0 mm (2.7 x 2.7 inches)
Fuel SystemCarburettor. Bing
Fuel ControlOverhead Valves (OHV)
IgnitionBattery
LubricationWet sump
CoolingAir
Transmission
Gearbox4-speed
Final DriveShaft drive (cardan) (final drive)
ClutchSingle plate dry-cable operated
Performance
Top Speed80.0 km/h (49.7 mph)
Fuel Consumption2.90 litres/100 km (34.5 km/l or 81.11 mpg)
Greenhouse Gases67.3 CO2 g/km. (CO2 - Carbon dioxide emission)
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.