In 1930, the Ariel Square Four made its debut at the Olympia Motor Show. The bike featured an unusual four-cylinder engine that essentially consisted of two vertical twins sharing a common crankcase, cast as a monobloc design. The result was an ingeniously compact and practically vibration-free engine. 1953 saw the introduction of the Mark II model, and its redesigned cylinder head helped the Ariel join the league of genuine 100 mph motorcycles.

This fantastic example was purchased by the consignor in 2016 and restored to concours standard by OCD Custom Cycles of Santa Fe, New Mexico in 2020, documented by a restoration summary and receipts on file, which total over $45,000. Its restoration was meticulously undertaken with countless parts refurbished, rebuilt, or replaced. The Ariel makes a stunning presentation in black, accented by gleaming chrome and gold striping. Serviced in 2023, the bike presents in impressive condition today, making this an outstanding opportunity to acquire an Ariel Square Four, one of the most innovative and unique motorcycles of the 1950s.