Norton square four motorcycle

The cylinder barrels were cast as a unit in a monobloc design. Their two crankshafts were joined by a flywheel and rotated in opposite directions. By having the two pistons of one crank at top and bottom dead center and the pistons of the second shaft at half stroke, the design was ingeniously compact and the firing order made it practically vibration free.

The Ariel Square Four 4F made its debut at the Olympia Motorcycle Show featuring an overhead camshaft cc with a hand shift for the Burman gearbox, which was integral with the crankcase. Overhead camshafts and unit construction were well into the future for most firms, so Ariel was a real pioneer.

Few knew then that the bike would become a legend of the British industry, both for its performance and dependability. In , the 4F was taken out to cc, although the remained available. The next year, a 4F fitted with a supercharger lapped the famous Brooklands speed bowl at miles per hour.

The 4G was introduced in with a new cc overhead-valve engine. To accommodate the larger displacement, a new crankshaft was set in a much stronger crankcase. To date, the innovative Ariel Square Four remains unique in motorcycling history; a true 'gentleman's motorcycle, this refined yet characterful machine retains an enthusiastic and loyal following, and is now a greatly appreciating classic, highly pri zed by discerning enthusiasts.

A pet project, the bike started as a ratty barn find and was subject to a full restoration with a few modifications. At the heart of the bike is a motor fully rebuilt by marque expert Chuck Walton. His knowledge is encyclopedic and having restored so many engines, understands every pitfall of the unique design and precisely how to prevent engine failure. Tricks to rod bolts a well-known weak point of the engine , rocker arms, crank bushings, valve guides and springs ensure engines with great power, superb reliability and great longevity.

The engine is mounted in its original and unmodified, unmolested frame, fully restored with a fresh powdercoat finish in black. All cycle parts have been restored or refurbished. The result is a bike that starts easily and idles well. It has the enormous grunt of a Square 4 of cc and sounds great. Royal Enfield Super Meteor spotted again!

Jan 10, Anuj Mishra. Jan 05, Anuj Mishra. Yezdi Roadster launched in India at Rs 1. Other Brands. Indian 3 bikes. Moto Guzzi 1 bikes. TVS 18 bikes. Hero 15 bikes. Honda 20 bikes. Bajaj 19 bikes. Suzuki 10 bikes. Royal Enfield 6 bikes. But what Jerry finds most gratifying about the finished project is the reaction of people who see it for the first time.

Coming up with the name was a challenge. Jerry considered Noriel, but rejected it. Thinking of building one yourself? The only person on the planet who can lay claim to being the first to win an AMA National road race aboard a bike bearing the fabled tuning fork logo.

Profoundly influenced and rejuvenated by the Badlands, Roosevelt went on to create the modern conservation movement. Readers ask Keith about problems surrounding their Triumph motorcycles with battery woes, oil leaks, and a sticky clutch. The Ariel Square Four engine looks at home in the Norton frame and fits with relatively minor modifications.

Published on Feb 9, Triumph Troubles Q and A Readers ask Keith about problems surrounding their Triumph motorcycles with battery woes, oil leaks, and a sticky clutch. Motorcycle Classics Magazine Featuring the most brilliant, unusual and popular motorcycles ever made!