The Seven was introduced by the fledgling Lotus in 1957
It was a road-legal sports car eligible for club racing
The Seven was of simplistic design and available to purchase as a kit car
Up front was a 40bhp 1.2-litre four-cylinder Ford engine that originated from the Model Y of 1932
A toolkit and jack was strapped in the luggage space, and the fuel tank and battery could be reached by removing the plywood floor
The Series 1 lasted until 1960 and the Series 4 until 1973. The rights and tooling to the Seven were then sold off to a dealership by the name of Caterham Cars…
"For the enthusiast with a desire for racing, the Seven is a safe and sensible vehicle," we wrote in 1957
The Seven's chassis was of tubular construction. Suspension was wishbones and coil springs at the front and a live axle with coil springs at the rear
"Reasonable protection is provided by the lightweight hood," we said, "while the cutaway body side allows plenty of elbow room"
When people talk about Lotus, the thing they'll always come back to is the company's obsession with simplicity and weight minimisation. These lead to great sports cars, so the theory goes.
And it's true. This is probably best validated by the Seven, be that in its original Lotus form, as a Caterham or, indeed, in any of its many other variations – of which there are so many as to warrant an entire Wikipedia article.
This lightweight sportster was introduced in 1957, just half a decade into Lotus's existence. It followed the Six, the car that really established the brand in the minds of the public. And it was essentially a development of its predecessor's mission, which was, as Autocar put it, to act as "a jumping-off point for the young enthusiast who wished to enter sports car racing without too much expenditure, while being usable as a normal road car, albeit with some degree of discomfort".
The Seven was based on a steel chassis frame of tubular construction "very similar to that of the more expensive streamlined models", clad in aluminium body panels, giving it a weight of just 1008lb, distributed in a perfect 50:50 ratio front to rear.
The engine, meanwhile, was a 1.2-litre four-cylinder 'side-valve' unit sourced from a Ford Prefect but with its origins in the Model Y of 1932. In the Seven, it produced 40bhp at 3400rpm and 58lb ft at 2600rpm. Although that sounds like nothing nowadays – indeed, it's exactly half the power output of the entry-level Caterham Seven 160's three-cylinder Suzuki motor – it still gave the car a ratio of 65.9bhp per ton, so 60mph could be achieved from rest in 17.8sec.
The engine drove the diminutive car's rear wheels via just three manual gears.
To buy a built Seven from Colin Chapman & Co would have cost £1036 and seven shillings. But you could avoid the hefty purchase tax by building it yourself – as a kit, it cost just £526.
Autocar's road testers of 61 years ago began: "An outstanding feature of the Seven is the road-holding and general stability. The suspension is, by normal saloon car standards, stiff, but not to the degree of the sports car of 20 years ago.
"Speed on corners seems to be limited only by visibility and/or the driver's experience. At first, the car gives the impression of wandering and lacking directional stability, but this disappears as soon as the steering wheel is allowed to float in the driver's hands. Hands off, the car will maintain a straight course. The steering is sensitive but free from any vice, and there are no noticeable oversteer or understeer characteristics.
"Although the steering only has two turns from lock to lock, the effort at the wheel is very low; one can take quick corrective action if the back end should hop, which it tends to do, probably because of the relatively high proportion of unsprung weight in such a light car. There is no reaction from the front wheels and, in this respect, the new wishbone suspension is a great improvement on the swing axle type of the Six, which was subject to gyroscopic kick and tended to wander on the straight."
Usually, the Seven's seating position would have been tailored to the buyer's requirements, so we could not fairly comment on this. However, we noted: "The small, two-spoked steering wheel is almost vertical and close to the facia; the outstretched position of the driver's arms is comfortable and gives full control.
"Cockpit space is limited and there is not much foot room around the pedals, although their angles are excellent and comfortable. Brake and accelerator are set so that heel-and-toe changes become a natural manoeuvre.
"When driving the Seven in reasonably traffic-free conditions, one soon forgets minor discomforts in the exhilaration of its performance and the manner of its achievement. The Prefect engine, mildly tuned in this case, gives an excellent power-to-weight ration and has no temperament.
"It quickly reaches operating temperature (no fan or water pump is fitted) and it will then give full throttle response without hesitation. Acceleration in the open country is very good and 35mph on the high first gear is reached very quickly (4.7sec) with a hard snarl from the exhaust. Second is close enough to top to give valuable hill-climbing performance. It provides a maximum speed of 70mph and is very useful for overtaking at speeds in excess of 50mph.
"Some saloon cars with not much larger engines, and capable of carrying four or more persons in great comfort, have higher maximum speeds than the Seven, but their occupants may never know the joy of driving such a car. It's a great pity that purchase tax prevents such cars as this, with especially high safety factors of road-holding, from reaching the hands of so many young enthusiasts who would benefit by the experience.
"The maximum speed of 81mph with two aboard is credible. With a small racing screen and further tuning of the engine, 90mph should be possible solo.
"The light weight of the Seven makes a three-speed gearbox acceptable. Very quick, definite changes can be made, but some care and practice is required to engage first when changing down from second. The clutch pedal pressure appeared fairly high, no clutch slop occurred during repeated standing start acceleration tests, and take-off was smooth once the short, stiff travel of the pedal has been mastered.
"Brakes of a size normally fitted to larger and heavier cars are used on the Seven. There are two-leading shoes in the front units, and the system is smooth and progressive. These characteristics may not at first appear to be reconciled with the 69% efficiency rating at 50lb of pressure, but this is because pedal pressures above this tend to lock the front wheels at 30mph, indicating that the ratio on the front wheels is too high at present. It's a rare occurrence for us to comment that a car's brakes are too powerful, but care was needed in applying the Seven's on wet roads to avoid locking the front wheels and losing adhesion for steering."
Our review certainly reads positively, but did we discover any inkling of its future status as a sports car legend?
Well, not quite. "For the enthusiast with a desire for racing," we concluded, "the Seven is a safe and sensible vehicle. Purchase tax makes it expensive, but those who can build it up themselves can avoid this burden. In its dual form of racer and road car, it is particularly suitable for the young beginner; with diligence, he can improve the standards of comfort for road use without detracting from its racing performance."
Well then, although we very highly doubt it, perhaps there will be thousands of variants of the Elemental RP1 by 2079 – that's if sports cars that can be driven on the road even exist by then.