1951 Ariel Square Four 1000cc


 • Beautifully restored example
 • Imported from the US
 • 1,000 cc four-cylinder

The Background

Known as one of the most glamorous British motorcycles, the Square Four was in production for Ariel’s range of motorcycles for over 27 years. The engine was designed by Edward Turner, a young engineer who later became the boss of Triumph. The Square Four design came from Turner, who initially sketched it onto the back of a cigarette packet as an idea, before offering it to different motorcycle manufacturers. 

It was Ariel who took him and his engine design on, and the first to be launched was the 500cc in 1930, followed by a 600cc two years later. The design had many problems, mainly overheating. The problems were addressed by Val Page, who was also famous within the industry, and they modified the 600cc and launched the larger 1000cc. 

Production was stopped due to World War II, but restarted in 1945, now featuring telescopic forks and the new 1000cc engine. The Square Four is one of the most revered British motorcycles of all time and it is incredibly easy to see why...

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The History

The 1951 Ariel Square four was found in the USA in project form and was imported to the UK in 1991. The bike was then restored in the UK which included a full strip down and rebuild, including the engine. 
The seller purchased the bike shortly after spotting it for sale 4 years ago, when a touch of nostalgia kicked in, with memories from his travels, usually going on holiday either on the back or in the sidecar of his dad's Square four, which was even known to have had a trailer attached, along with the sidecar, thus proving the huge amount of Torque this fantastic engine can produce.

With these memories, the seller knew he had to have it, and add it to his lovely collection of classic bikes. A move to warmer climates has brought on the sale of his much loved Ariel Square Four.

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The Paperwork

The V5 is present and shows 2 previous keepers since the registration of the bike on 30th April 2008. There is an import certificate showing the bike actually came into the country on 15th May 1991, through East Midlands Airport. 
There are a few invoices for some odd parts over the years, and some old MOT certificates from around 2008.

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The Exterior

This 1951 Ariel Square Four 1000cc has been very well cared for and maintained to a high standard since its restoration which is simply stunning. As we walk up to the machine, we are instantly taken by its gorgeous maroon and black paintwork which is oh so reminiscent of a time when British machines dominated the roads around the world. The restoration work has now aged appropriately for the machine and although there are some small blemishes to be expected for a loved British motorcycle, these are very minor and add to the allure of the ownership of this now 70 year old icon. 

The headlight works as it should and has a built-in amperes gauge which is reported to be working as it should. The handle bars are in good order with no or little corrosion to be seen to them or the mirrors. The odometer is showing a reading of 20,995 miles.
The frame and forks have been powder coated in black for a strong durable finish. Sitting atop the frame, the beautiful maroon fuel tank has been finished with a gold pinstripe and then lacquered over for a beautifully ornate finish. The oil pressure gauge (a rare addition to British Motorcycles of this period) is working correctly and the rubber Ariel knee pads mounted to the sides are an attractive addition both aesthetically and for comfort. 

The sprung seat has some light signs of wear to the edges but nothing too excessive, and would be quite easy to get recovered should you wish. With the option for a pillion passenger there is a seat mounted to the mudguard and some fold away footrests, and like the front, the rear mudguard is in good condition. 
The chrome wheels look to be in beautiful condition with a nice bright finish and the hubs have been painted with the same colour scheme as the fuel tank. 

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The Mechanics

The Square Four has a very unique 1000cc 4-cylinder engine, capable of pushing the Ariel to near 100 mph which was utterly blistering for it's time. There are photographs with the engine stripped down for the rebuild when the bike was restored. 

The Ariel starts and runs with a pleasing tick-over thud that is instantly recognisable as a square four. The seller reports that the ride is smooth from the punchy 1000cc engine and perfectly capable of providing some ton up thrill along the way! The machine appears to select its four gears as it should and the brakes are perfectly adequate for the machine's vintage. 

The seller is a serial classic British motorcycle owner and knows his way around these machines (only buying what he considers the best available!) and has advised that he has only used it for a few short runs to local shows, but in those brief experiences it has ridden superbly and is more than capable as a long distance tourer, providing both Grace, Pace and a sense of reassuring mechanical prowess only offered by the four cylinder Ariels of that period. 

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The Appeal 

Without doubt one of the most innovative engine designs of the time, the Square Four 1000cc is a joy to own in modern times.

Of course, there is a huge following for this appreciating classic and this particular machine is more than willing to prove to us that she is still more than in her prime! Both a beautiful bike to enjoy and to invest in, you could fit right in with any Vintage Motor Cycle Club event or turning up the local transport café where one will bring in admiring glances from even the most seasoned of ton-up boy. 

Notice to bidders

Although every care is taken to ensure this listing is as factual and transparent as possible, all details within the listing are subject to the information provided to us by the seller. Car & Classic does not take responsibility for any information missing from the listing. Please ensure you are satisfied with the vehicle description and all information provided before placing a bid.

As is normal for most auctions, this vehicle is sold as seen, and therefore the Sale of Goods Act 1979 does not apply. All bids are legally binding once placed. Any winning bidder who withdraws from a sale, is subject to our bidders fee charge. Please see our FAQs and T&C's for further information. Viewings of vehicles are encouraged, but entirely at the seller's discretion.

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Auction FAQs
Auction Details
  • Year 1951
  • Make Ariel
  • Model Square Four 1000cc
  • Colour Red and Black
  • Mileage 20,995 Miles
  • Engine size 997
  • Seller Type Private
  • Town Grantham
  • County Lincolnshire
  • Country United Kingdom
  • Auction ends
Bidding history
8 Bids from 5 bidders
  • Daveloe•••• £11,000 19/07/22
  • patrick•••• £10,300 19/07/22
  • Daveloe•••• £10,000 19/07/22
  • Daveloe•••• £9,200 19/07/22
  • edward.•••• £9,100 17/07/22
  • busycyc•••• £9,000 16/07/22
  • bailey.•••• £8,100 15/07/22
  • busycyc•••• £8,000 12/07/22

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