Ariel MK1 Square Four 1951 - Specifications & Review

Introducing the timeless 1951 Ariel MK1 Square Four, a motorcycle that stands as a testament to mid-century British engineering. Positioned as an allrounder, the MK1 Square Four embodies a unique blend of performance, style, and innovative design that makes it a beloved choice among classic motorcycle enthusiasts. With its distinctive square engine configuration and robust build, this motorcycle captures the spirit of post-war Britain, delivering not just transportation, but an experience steeped in nostalgia and craftsmanship.

At the heart of the MK1 Square Four lies a 997cc single-cylinder, four-stroke engine that produces a respectable 40 horsepower at 5,800 RPM. This power is delivered smoothly through a chain final drive, allowing riders to experience a delightful balance of torque and responsiveness. The carburettor fuel system ensures consistent performance, giving the bike a character that is both engaging and lively. With a weight of 193 kg (425.5 pounds) and a power-to-weight ratio of 0.2073 HP/kg, the MK1 Square Four offers an exhilarating ride that feels nimble and confident on various terrains, making it an ideal companion for both city cruising and weekend adventures.

The Ariel MK1 Square Four is packed with features that enhance both rider comfort and safety. Its tubular single-loop frame provides a sturdy foundation, while the expanding drum brakes—178 mm in the front and 203 mm in the rear—offer reliable stopping power. With a fuel capacity of 23 liters (6.08 gallons), riders can embark on longer journeys without frequently worrying about refueling. The classic aesthetics of this motorcycle, accentuated by its sleek lines and vintage charm, make it a standout piece in any collection, appealing not just to riders, but also to those who appreciate the artistry of motorcycle design.

Pros:

1. Unique Engine Configuration: The square four engine offers a distinctive performance and sound that sets it apart from other motorcycles of its era.
2. Comfortable Riding Experience: With a well-balanced frame and responsive handling, the MK1 Square Four provides a comfortable ride for both short jaunts and long-distance travel.
3. Timeless Design: Its classic styling and robust build make it an attractive option for collectors and vintage motorcycle enthusiasts.

Cons:

1. Weight: At 193 kg, it may feel heavier compared to more modern motorcycles, which can affect maneuverability for some riders.
2. Drum Brakes: While reliable, the drum braking system may not provide the same stopping power or feel as newer disc brakes, especially in wet conditions.
3. Fuel Efficiency: The carburettor system, while nostalgic, may not be as fuel-efficient as contemporary fuel injection systems, requiring more frequent stops at the pump during longer rides.

The 1951 Ariel MK1 Square Four is not just a mode of transportation; it’s a piece of history, a conversation starter, and a symbol of a bygone era that continues to captivate riders today.