The Ariel Square 4 design goes all the way back to 1931, soon after Edward Turner designed an interesting new four-cylinder motorcycle engine formed from two OHC parallel twins. The design became known as the square four engine, and lent its name to this Ariel motorcycle. Turner had actually shopped his engine design out to other British firms, but BSA rejected it.
By 1953, the Ariel Square Four had already gone through a few revisions, and was formally known as the Mark II. The Mark II featured a 997 cc engine. Upgrades to the powerplant included separate barrels, a new cylinder head, and four exhaust pipes, which bumped up horsepower to 40. This enabled the Square Four to ‘do the ton’, even with a curb weight of 425 pounds.
This specific Ariel Square 4 (VIN: TM 1002) has 35,000 miles and is being offered by the fifth owner. Amusingly, the first four owners were all named David. Maybe you’ll get a discount if you share the same name? It’s been with the current owner since 1996, during which time the bike received a complete restoration. Apparently it was ridden for just an hour after the restoration and then setup as a static display. Everything is claimed to work, and it comes with the original ignition key and ‘jiffy’ side stand.
Find this Ariel Square 4 for sale in Burnaby, British Columbia, Canada with bidding up to $11,100 and the reserve not yet met