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Naked bike · 1926

R39

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MotoLibrary Score
36 /100 Commuter
Power
6 HP
Top Speed
100 km/h
Engine
247 ccm

1926 BMW R39 Technical Analysis & Specification Breakdown

Built around BMW's naked motorcycle platform, the 1926 BMW R39 relies on a 247 cc (15.1 cu in) air-cooled single cylinder, four-stroke powerplant. In factory specification, peak output is rated at 6 HP (4.4 kW) at 4,000 rpm, transferring power to the rear wheel through a 3-speed gearbox and shaft drive (cardan) final drive. With a specific output of 24.3 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 R39 measures 110 kg (243 lbs) wet (curb), translating to a power-to-weight ratio of 0.05 HP/kg (18.33 kg per horsepower).

Within MotoLibrary's BMW archive, this model family spans 2 indexed model years from 1926 to 1927, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.

Specific Output
24.3 HP/L
Power-to-Weight
0.05 HP/kg (18.33 kg/HP)
Engine
Displacement 247.0 ccm (15.07 cubic inches)
Engine Type Single cylinder, four-stroke
Engine Details Single cylinder, four-stroke
Power 6.0 HP (4.4 kW)) @ 4000 RPM
Compression 6.1:1
Bore x Stroke 68.0 x 68.0 mm (2.7 x 2.7 inches)
Fuel System Carburettor. 20mm BMW Spezial
Fuel Control Overhead Valves (OHV)
Lubrication Wet sump
Cooling Air
Transmission
Gearbox 3-speed
Final Drive Shaft drive (cardan) (final drive)
Clutch Dry-single plate-cable operated
Performance
Top Speed 100.0 km/h (62.1 mph)
Chassis
Frame Type Steel doble cradle
Front Suspension Leading link
Rear Suspension Rigid
Wheels & Brakes
Front Tyre 3.5-27
Rear Tyre 3.5-27
Front Brakes Expanding brake (drum brake)
Dimensions & Weight
Weight incl. 110.0 kg (242.5 pounds)
Overall Height 950 mm (37.4 inches)
Overall Length 2050 mm (80.7 inches)
Overall Width 800 mm (31.5 inches)
Other
Starter Kick
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Buying Checklist

Before You Compare This Bike

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
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Brakes
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Suspension
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Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
Rider Profile

Who Is This Bike For?

🟢
Beginner
A2 license compatible, manageable power.
🏍️
Best For
City & Weekend Rides
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