The 1953 Ariel Square 4 MKII is a legendary British motorcycle known for its advanced engineering, smooth performance, and distinctive four-cylinder engine layout. Introduced by Ariel Motorcycles, this model represents the pinnacle of development for the Square Four series, a range renowned for blending power with refinement.
Overview
- Manufacturer: Ariel Motorcycles (Birmingham, England)
- Production Years: 1953–1959 (for the Mark II version)
- Designer: Edward Turner (original concept in 1928)
- Class: Touring motorcycle
Engine Specifications
- Type: 997cc OHV air-cooled four-cylinder engine
- Layout: Square configuration (two parallel twin engines sharing a common crankcase)
- Bore x Stroke: 65mm x 75mm
- Compression Ratio: 7.2:1
- Power Output: Approximately 42 horsepower at 5,800 rpm
Transmission
- Type: 4-speed manual with a foot-operated gear shift
Performance
- Top Speed: Around 100 mph (160 km/h)
- Acceleration: Known for smooth and strong torque delivery
Design Features
- Chassis and Frame:
The Mark II featured a full cradle frame with a telescopic front fork and plunger rear suspension (early models), providing stability and comfort. - Brakes:
Drum brakes on both front and rear wheels, typical of the era. - Weight:
Dry weight approximately 465 lbs (211 kg). - Exhaust:
The Mark II is easily recognized by its distinctive twin exhaust pipes exiting from each side of the engine, a design that enhanced its performance and iconic appearance.
Innovations and Notable Attributes
- Unique Square Four Engine:
The engine’s configuration provided a unique blend of power and smoothness, minimizing vibration compared to parallel twins of the same era. - Improved Cooling:
The Mark II introduced redesigned cylinder heads and separate exhaust ports to address overheating issues found in earlier versions. - Luxury Touring Bike:
It was marketed as a high-performance touring motorcycle, offering a refined ride with ample power for long-distance cruising.
Legacy
- End of an Era:
Production of the Ariel Square Four ceased in 1959, marking the end of an iconic British engineering marvel. - Collectibility:
The Mark II is highly sought after by collectors and enthusiasts for its unique engineering, historical significance, and elegant design. - Influence:
Edward Turner, who later became Triumph's chief designer, was instrumental in developing the motorcycle’s concept, which influenced other classic British motorcycles.
Summary
The 1953 Ariel Square Four MK II represents a masterpiece of British motorcycle engineering. Combining elegance, innovation, and robust performance, it stands as one of the most refined and technically advanced motorcycles of its time. Its smooth-running engine and classic design make it a cherished piece of motorcycling history.
You may purchase a print of the 1953 Ariel Square 4 MKII in our 2019 online gallery.
Taken at the Hilton Head Island Concours d'Elegance & Motoring Festival.
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