***Vendor supplied images***
Highlights
- Exquisitely engineered 1000cc 4-cylinder engine with twin 180-degree crankshafts
- Restored by the vendor who has owned the bike since 1998
- One of the last post-war Mk1 examples, with aluminium alloy head and block
The Appeal
While 4-cylinder engines are a less unusual sight in motorcycles these days, shoehorning such an engine into a bike during the 1930s required some seriously innovative engineering.
Keen to capitalise on the torque and smooth power delivery afforded by 4-cylinder units but avoid the use of expensive shaft-drive or bevel gearing, Ariel rejected conventional ‘boxer’ and V4 designs in favour of Edward Turner’s diagonally opposed ‘square four’ layout.
The result was a bike that would evolve over the years from a 500cc to a 1000cc example, which is exactly what we have here. Formerly a display piece for some years, this 1952 example has been in the same owner’s possession since 1998, during which time it has been carefully restored to running and riding order.
The History and Paperwork
- Restored gradually since 1998 by the current owner
- Apparently used as a showroom display piece for c.20 years in Guisley, Yorkshire
- Most likely part of a sidecar outfit as it had square profile tyres in 1998
- Original registration book shows details of the first 7 owners, all living in the Yorkshire area
- Original logbook
- Dating certificate from Dragonfly British bike experts, showing the bike was sold to a London bike dealer from new
- Matching engine and frame numbers confirmed by Dragonfly’s records
- Owner's manual present
- Numerous parts manuals and parts lists
- Large file of invoices for parts
- Serviced and maintained by the vendor since 1998
- Restored to a a running and riding standard
The Condition
- Sympathetically restored
- Sprung single seat with pillion passenger seat
- Very presentable paint and brightwork
Having been carefully restored over a number of years, this bike is in very good order. The brightwork is quite smart, without being over-restored and the same goes for the black paintwork, which has quite a matte finish, displaying various imperfections in places. While the next owner may wish to achieve a slightly higher level of finish on the tank and mudguards, we really like the slightly ‘oily rag’ aesthetic of this Ariel and we would enjoy it as is.
The sprung seat appears in good condition and there is also room for a pillion passenger atop the rear mudguard. Various rubber components such as the knee grips and foot pegs are quite serviceable, with little in the way of splitting or wear we could discern.
The wheels retain a nice gleam and the vendor informs us that the tyres are new.
The Mechanics
- Aluminium alloy head and cylinder block
- Replacement Amal carburettor
- Numerous spare parts and special tools
While we understand that this Ariel spent much of its life as a display piece, we’re pleased to report that the vendor has restored it to running and riding condition.
At the heart of the Square Four lies the engine that gives the bike its name. The 1000cc powerplant was remarkably compact for the time by arranging its pistons in a square, diagonally-opposed orientation, driving two 180-degree crankshafts which allowed for a flywheel and chain drive to the rear wheel.
Despite the innovative nature of this setup, the Square Four performed really well and was advertised as the bike that could go from 10 to 100 mph in top gear.
Upon start up, this 1952 motorcycle immediately attracts attention from onlookers, who doubtless suspect to hear the rhythmic thud of a single or twin-cylinder British bike. Instead, the Ariel bursts into life with a healthy exhaust note, those small, short stroke pistons busily chattering away and cancelling out each other's inertia.
The vendor informs us that this bike runs really smoothly, delivering ample torque and power to the rear wheel. Weighing in at around 200 kilograms, these weren’t light bikes, but their innovative power unit granted the Square Four the performance to deal with this. As a late Mk1 example, his 1952 bike benefits from the aluminium alloy head and block, reducing the overall weight and providing superior heat dissipation.
The vendor tells us that it uses a little oil, as most bikes of this vintage do and it also delivers some to the chain through the mechanical oiling system as it should.
This bike is now running an Amal carburettor, the vendor informing us that the original specification Solex is included.
Beside this, we are informed that the following parts are new:
Beside this, we are informed that the following parts are new:
- Oil filter kit
- Battery box
- Morgo oil pump
- Clutch
- Brake pads
- Rear chain
- Timing chain
- Oilways
- Cables
- Silencers
The bike is also supplied with a few special tools, for working on that complex engine.
Summary
A real technological tour de force and an important landmark in the history of the motorcycle, the Ariel Square Four is a must-have in any comprehensive bike collection and this sympathetically restored 1952 example is ready to be used and enjoyed.
Notice to bidders
This item is sold on an ‘As is Where is’ basis. The condition of this item is the opinion of the seller and may differ from your own opinion. Photos and listing descriptions are for guidance purposes only*.** Car & Classic do not warrant listing accuracy. Full inspection is recommended. Viewings are at the seller’s discretion. Buyer is responsible for delivery and collection of any item purchased.*
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