
BMW R51
Key specifications
Overview
Introducing the 1939 BMW R51: A Timeless Classic on Two Wheels The 1939 BMW R51 stands as a testament to the brand's commitment to engineering excellence and innovative design during a pivotal era in motorcycle history. Positioned in the allround category, the R51 was crafted for riders seeking a balance of performance, reliability, and comfort. This model represents a significant leap forward for BMW, showcasing their mastery of the iconic boxer engine layout and establishing a legacy that enthusiasts still cherish today. With its elegant lines and robust design, the R51 remains a sought-after classic, appealing to collectors and riders who appreciate the rich heritage of German engineering. At the heart of the R51 lies a sophisticated two-cylinder boxer engine, displacing 494cc and delivering a robust 24.07 horsepower at 5600 RPM. This four-stroke powerhouse is configured with a 6.7:1 compression ratio, allowing for spirited acceleration and a top speed of 140 km/h (87 mph). Riders will appreciate the smooth power delivery and the distinctive thrum of the boxer engine, which provides a unique riding experience that’s both engaging and memorable. The R51's 4-speed gearbox and shaft drive contribute to its effortless handling, making it a superb choice for both leisurely rides and spirited outings. The R51 is not just about power; it incorporates features that elevate the riding experience. Its steel single-cradle frame ensures durability while maintaining a lightweight feel, complemented by a sophisticated cartridge front suspension and a twin-shock swingarm at the rear. Stopping power is delivered through dual 200 mm drum brakes, providing reliable performance even in challenging conditions. With a fuel capacity of 14 liters, riders can embark on longer journeys with confidence, knowing they have the range to explore the open road. The classic kick starter adds to the nostalgic charm, reflecting the era's simplicity and mechanical beauty. ###
Pros
Cons
- Iconic Boxer Engine: The unique two-cylinder boxer design offers a distinctive riding experience with a low center of gravity and smooth power delivery.
- Timeless Aesthetics: The elegant styling and classic lines make the R51 a true head-turner, appealing to vintage motorcycle enthusiasts and collectors alike.
- Comfortable Ride: The combination of robust suspension and ergonomic design ensures a comfortable ride for both the rider and passenger, making it ideal for longer journeys.
- Limited Modern Features: As a classic motorcycle, it lacks some modern conveniences such as electric start and advanced braking technologies.
- Maintenance Requirements: The vintage design may require more frequent maintenance and care, especially for parts that are no longer in production.
- Performance Compared to Modern Bikes: While remarkable for its time, the R51’s performance may feel less powerful compared to contemporary motorcycles, which can dissuade some riders seeking high-performance capabilities.
Technical details
Source specification data
- Make
- BMW
- Model
- R51
- Category
- Allround
- Starter
- Kick
- Power
- 24.07 HP (17.6 kW)) @ 5600 RPM
- Clutch
- Dry-single plate-cable operated
- Gearbox
- 4-speed
- Ignition
- Battery
- Top Speed
- 140.0 km/h (87.0 mph)
- Fuel System
- Carburettor. Amal
- Bore X Stroke
- 68.0 x 68.0 mm (2.7 x 2.7 inches)
- Compression
- 6.7:1
- Displacement
- 494.00 ccm (30.14 cubic inches)
- Cooling System
- Air
- Engine Details
- Two cylinder boxer, four-stroke
- Lubrication System
- Wet sump
- Transmission Type Final Drive
- Shaft drive (cardan)
- Fuel Capacity
- 14.00 litres (3.70 gallons)
- Overall Width
- 815 mm (32.1 inches)
- Overall Height
- 960 mm (37.8 inches)
- Overall Length
- 2,130 mm (83.9 inches)
- Weight Incl Oil Gas Etc
- 182.0 kg (401.2 pounds)
- Seat
- Single seat
- Rear Tyre
- 3.50-19.00
- Frame Type
- Steel single cradle
- Front Tyre
- 3.50-19.00
- Rear Brakes
- Expanding brake (drum brake)
- Front Brakes
- Expanding brake (drum brake)
- Rear Suspension
- Twin shock-Swingarm
- Front Suspension
- Cartridge
- Rear Brakes Diameter
- 200 mm (7.9 inches)
- Front Brakes Diameter
- 200 mm (7.9 inches)