Ariel 4G Square Four Mark II - Specifications & Review

Company History

Ariel is among Britain’s most storied names, moving from bicycles to motorcycles in the brass era and innovating through several epochs. The Red Hunter singles set a standard for sporting roadsters, while Edward Turner’s Square Four delivered creamy long-distance power from a compact four-cylinder layout. Postwar Ariels carried commuters and enthusiasts alike, with alloy cylinders and tidy frames that showcased the firm’s engineering finesse. The two-stroke Leader/Arrow of the late 1950s pushed modernity—enclosed bodywork, pressed steel, unit construction—foreshadowing scooters and lightweight commuters. Industry headwinds and consolidation into BSA/Triumph eventually ended motorcycle production in the late 1960s. In the 21st century, the Ariel name returned on radical lightweight cars and a boutique V-4 motorcycle prototype, channeling the brand’s historic appetite for bold design. Historically, Ariel symbolizes British ingenuity: elegant solutions to packaging and power delivery, a willingness to try new materials and layouts, and an understanding that motorcycles could be both fast and refined. A well-sorted Square Four remains a bucket-list ride—silky midrange, dignified pace, and the sense of traveling with civilized authority.