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BMW R12 Twin carb
1938Sportbike

BMW R12 Twin carb

Key specifications

Engine
745 cc
Power
20 HP
Fuel type
petrol
Fuel capacity
3.7 L
Transmission
4-speed
Front brakes
Expanding brake (drum brake). Single
Rear brakes
Expanding brake (drum brake)

Overview

Introducing the 1938 BMW R12 Twin Carb: A Classic Sport Motorcycle Step back into the exhilarating world of pre-war motorcycling with the 1938 BMW R12 Twin Carb, a distinguished member of BMW's legendary lineup. Positioned as a sport motorcycle, the R12 was engineered to embody the spirit of adventure and performance, capturing the hearts of enthusiasts during its era. With its timeless design, characterized by the iconic BMW styling and robust engineering, the R12 remains a sought-after piece for collectors and vintage motorcycle aficionados alike. Its combination of classic aesthetics and cutting-edge technology for the time makes it a true icon of two-wheeled history. At the heart of the R12’s charm lies its impressive two-cylinder boxer engine, displacing 745cc and producing nearly 20 horsepower at 4,000 RPM. This four-stroke powerhouse propels the motorcycle to a top speed of 120 km/h (74.6 mph), providing a thrilling ride that combines agility with stability. The 5.2:1 compression ratio and the precision of the Amal carburettor contribute to a smooth power delivery and responsive throttle, making the R12 an engaging ride whether you're carving through winding roads or cruising along open highways. The bike’s 4-speed gearbox offers effortless gear transitions, ensuring that riders can enjoy the full potential of its performance while navigating various terrains. The R12 boasts several noteworthy features that reflect BMW's commitment to innovation. Its steel double cradle frame provides excellent rigidity and stability, crucial for both spirited rides and long-distance journeys. The motorcycle is equipped with reliable drum brakes—200 mm single expanding brakes in the front and a matching system in the rear—offering ample stopping power. The cartridge front suspension complements the bike's handling characteristics, allowing for a comfortable ride despite its rigid rear suspension. With a fuel capacity of 14 liters, the R12 is designed for longer excursions, adding to its appeal as a touring motorcycle in the sport category. Lastly, the traditional kick starter adds a nostalgic touch that connects riders with the roots of motorcycling. **

Pros

  • Timeless Design: The classic styling and craftsmanship of the R12 make it a standout piece for collectors and enthusiasts.
  • Solid Performance: The boxer engine provides a unique riding experience with smooth power delivery and respectable top speed for its time.
  • Durability and Reliability: The robust steel frame and well-engineered components ensure that the R12 can withstand the rigors of both daily rides and long adventures.

Cons

  • Limited Speed: While respectable for its era, the top speed may not satisfy modern riders looking for exhilarating performance.
  • Weight: At 185 kg (407.9 lbs), the R12 can feel heavy for newer riders or those accustomed to lighter motorcycles.
  • Maintenance Complexity: The vintage technology and components may require specialized knowledge and parts, making maintenance a challenge for some owners.

Technical details

Source specification data

Make
BMW
Model
R12 Twin carb
Category
Sport
Starter
Kick
Carrying Capacity
300
Power
19.99 HP (14.6 kW)) @ 4000 RPM
Clutch
Dry multiplate-cable operated
Gearbox
4-speed
Top Speed
120.0 km/h (74.6 mph)
Fuel System
Carburettor. Amal
Bore X Stroke
78.0 x 78.0 mm (3.1 x 3.1 inches)
Compression
5.2:1
Displacement
745.00 ccm (45.46 cubic inches)
Cooling System
Air
Engine Details
Two cylinder boxer, four-stroke
Lubrication System
Wet sump
Fuel Capacity
14.00 litres (3.70 gallons)
Overall Width
900 mm (35.4 inches)
Overall Height
940 mm (37.0 inches)
Overall Length
2,100 mm (82.7 inches)
Weight Incl Oil Gas Etc
185.0 kg (407.9 pounds)
Seat
Spring-mounted seat
Rear Tyre
3.5-19
Frame Type
Steel-doble cradle
Front Tyre
3.50-19
Rear Brakes
Expanding brake (drum brake)
Front Brakes
Expanding brake (drum brake). Single
Rear Suspension
Rigid-
Front Suspension
Cartrige
Front Brakes Diameter
200 mm (7.9 inches)