Post-Sale Update: This Square Four sold for $10,605 on eBay.
The Ariel Square Four 1000 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.
By 1953, the Ariel Square Four 1000 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 Four 1000 (VIN: CGM1946) is nearly finished with a restoration, but the seller is focusing on a different vehicle. Mechanically, everything works – the listing includes a video of the bike being started and running:
Cosmetically, the frame has been stripped and powdercoated, and the sheetmetal has been primered. Throw on some mufflers, paint it whatever color you want, and you’ll have a solid example of one of Ariel’s finest.
Find this Ariel Square Four 1000 for sale in Spokane, Washington with bidding up to $9,000