Back to Bike FinderYears: 1923 · 1922 · 1921 · 1920 · 1919
Harley-Davidson Sport Twin
1921Sportbike

Harley-Davidson Sport Twin

Key specifications

Engine
590 cc
Weight
120 kg
Fuel type
petrol
Fuel capacity
2.6 L

Overview

### The 1921 Harley-Davidson Sport Twin: A Vintage Icon of American Engineering Step back into the roaring twenties, a time of innovation and spirited competition, and you’ll find the 1921 Harley-Davidson Sport Twin standing at the forefront of the motorcycle revolution. Positioned in the sport category, this motorcycle was designed for riders seeking both performance and style, bridging the gap between leisurely rides and spirited sport competition. With its sleek lines and formidable stature, the Sport Twin captured the hearts of enthusiasts who valued not only the thrill of the ride but also the craftsmanship of an American classic. A true embodiment of Harley-Davidson's legacy, this model paved the way for the brand's future in the sport motorcycle segment. At the heart of the Sport Twin lies a robust 589.97 ccm (36.00 cubic inches) twin-cylinder, four-stroke engine that generates an impressive performance for its time. With a compression ratio of 3.8:1, this engine delivers a delightful power band that allows for smooth acceleration and responsive handling, making it a joy to navigate both winding roads and straightaways. The bore and stroke dimensions of 69.9 x 76.2 mm contribute to a well-balanced engine that rewards riders with a spirited ride. The air-cooled design, paired with a reliable magneto ignition system, ensures that the Sport Twin remains dependable even on longer journeys. Riders can expect an exhilarating experience as the chain-driven system provides efficient power delivery to the rear wheel, making every twist of the throttle a memorable adventure. The Sport Twin is not just about raw power; it embodies engineering ingenuity with its tubular steel frame that offers a blend of strength and lightweight design. The front suspension features a trailing link with a single downtube, providing stability and comfort when tackling uneven terrains, while the rear suspension is rigid, giving the rider that classic vintage feel. With a weight of just 120 kg (264.6 pounds) and a fuel capacity of 10.00 liters (2.64 gallons), this motorcycle strikes an excellent balance between agility and endurance, making it suitable for both city commuting and countryside escapades. The carburettor fuel system ensures a consistent flow of fuel, allowing for smooth operation regardless of the conditions. **

Pros

    Cons

    • Iconic Design: The vintage aesthetic of the Sport Twin captures the essence of early 20th-century American motorcycling.
    • Smooth Handling: The combination of a lightweight frame and innovative suspension design provides excellent maneuverability and stability.
    • Reliable Performance: The powerful twin-cylinder engine offers a thrilling ride with dependable power delivery, perfect for both new and seasoned riders.
    • Limited Technology: As a motorcycle from the early 1920s, it lacks modern features such as disc brakes and advanced suspension systems that could enhance safety and comfort.
    • Rigid Rear Suspension: While providing a classic feel, the rigid rear suspension may limit comfort on long rides or uneven surfaces.
    • Fuel Efficiency: The carburettor system, while functional, may not provide the fuel efficiency seen in contemporary motorcycles, leading to more frequent refueling stops.

    Technical details

    Source specification data

    Make
    Harley-Davidson
    Model
    Sport Twin
    Category
    Sport
    Clutch
    Three speed
    Ignition
    Magneto
    Fuel System
    Carburettor
    Bore X Stroke
    69.9 x 76.2 mm (2.8 x 3.0 inches)
    Compression
    3.8:1
    Displacement
    589.97 ccm (36.00 cubic inches)
    Cooling System
    Air
    Engine Details
    Twin, four-stroke
    Transmission Type Final Drive
    Chain
    Dry Weight
    120.0 kg (264.6 pounds)
    Fuel Capacity
    10.00 litres (2.64 gallons)
    Rear Tyre
    3-26
    Frame Type
    Tubular steel
    Front Tyre
    3-26
    Rear Suspension
    Rigid
    Front Suspension
    Trailing link with single downtube