This is from the site Bring a Trailer (https://bringatrailer.com/) ...
This custom is believed to have been built in Pasadena around 1963, combining a Norton Featherbed frame and Ariel Square Four engine into one very interesting motorcycle. Featherbed frames were among the most advanced and best handling of the day, and though popular for Triumph and other engine swaps, this is the first we’ve heard of one being fitted with a Squariel. Named Esquire per original paint remnants on the aluminum tank, the seller reports that it’s ready to ride following a recent tune and fresh tires. Find it here on eBay in Bend, Oregon with a $22k BIN. Special thanks to BaT reader Paul C. for this submission.
Says the seller: “Reportedly built at the Milne Bros. shop in Pasadena, California around 1963, this is the marriage of a 1956 Ariel Square Four drivetrain and a 1959 Norton Featherbed chassis and is a true vintage hot rod. Much of the British motorcycle industry’s best is represented in this custom. Originally named “Esquire,” the aluminum tank still shows original patina. The seat has been professionally recovered in leather. New stainless steel spokes on original Dunlop alloy wheels. New tires and fresh maintenance make this a completely ready-to-ride vintage classic.”
Here’s a look at the unusual Square Four, which is essentially two vertical twins whose cranks have been geared together in order to provide a single driven shaft into the 4-speed transmission. There are no details on what the recent tuneup consisted of, but the seller does note that the bike’s charging system remains weak, adding that it’s adequate for a day of riding anyway.
Though not the most powerful or sporting motors ever built, these twin-crank fours are nonetheless mechanically fascinating, and they make a pretty cool sound too. In combo with this frame and nice, high handlebars, it should make for a unique, comfortable cruiser with a good turn of handling thrown in as a bonus. Fix the charging system, change the I’s on the tank to A’s and enjoy.