Ariel Square Four - Featured

1958 Ariel Square Four

Post-Sale Update: After 16 bids on eBay, this bike did not meet reserve at $17,550.

The Ariel Square Four 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. The bike was produced until 1959, making this example one of the last few out of the factory.

Ariel Square Four - Left Side

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.

Ariel Square Four - Engine

This specific Ariel Square Four is in great shape, having received a minor refresh in 2011 at Bancroft Vintage Motor Works. It got a mechanical tune up, as well as a repaint to original colors/stripes, and a new wiring harness. The odometer read just over 13,000 miles before it was reset after the bike’s refresh. All in all, the seller says that this bike runs great.

Ariel Square Four - Gauges

Find this Ariel Square Four for sale here on eBay with the opening bid at $8,000 in Akron, Ohio.

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