It speaks volumes about how faithfully Caterham has stuck to the formula over the years that anyone familiar with a new Seven could jump in one more than 30 years old and not really have to think about how to make it work.
Legroom aside, the car still seems to fit in exactly the same way. It’s like going back to your childhood home and discovering you know by instinct the exact location of every switch and handle in the building.
It sounds brilliant, quieter than you’d think at idle but rich, characterful and loud as the revs rise. It’s fast, too: the 1.6-litre motor has a modest 126bhp but that’s plenty in a 527kg car, enough to give a power-to-weight ratio just a little better than that of a new, 315bhp Porsche Boxster S.
Suddenly, you realise that however quick that 0-60mph time must have seemed in 1975, it gives a very poor impression of the car’s performance. Were it not for the limited traction of the live axle, period tyres and the perhaps more merciful nature of that generation of road tester, it would have gone far, far faster.
Subjectively, it feels like a 5.5sec car or thereabouts. The torque spread is also easily wide enough to cover the gaps between the ratios of the beautifully mechanical four-speed gearbox.
But it is the way the car handles that is such a revelation. It’s so softly suspended that you can’t merely feel the nose drop as you brake; you can see it. Angle the steering left and right and you can feel the car orbit around its central axis. It should be a recipe for disaster, but because there’s so little mass to control, it works brilliantly.
Even in the wet, traction is excellent for a car with a live rear axle, and when it slides, which it does readily, it doesn’t flick or snap but rolls gently into the most benign oversteer. It would be dead slow on the track, not least because there’s no limited-slip differential, but for slithering around the lanes with the twin-cam howling away at you, it’s marvellous.
Indeed, it’s only significantly let down by its ride: over rough surfaces, there a little too much bouncing and bump-steer to make it a wholly comfortable and relaxing experience.
The new car awaits its turn, a menacing presence at the side of the road. Impressively, its quoted weight is scarcely any more than that of its antecedent, although that doesn’t include all the weather equipment thankfully fitted to the test car. With 180bhp from its 2.0-litre Ford motor, it’s clearly going to be a lot quicker. But more fun? That remains to be seen.
Something was lost from the sound of all Caterhams that day in the 1990s when the company was forced to fit fuel injection, and while the Duratec sounds purposeful enough, after the Twin Cam you miss the induction hammer urging you on your way.
But there’s no doubting the extra urge. At any speed, it hauls effortlessly and easily away from its grandparent. The only disappointment is the five-speed gearbox, which is still a Ford-Sierra-based unit but superior only in quantity of ratios to the Cortina unit in the Twin Cam.
The greater change is in how the new car handles. With its de Dion rear axle, double wishbone front suspension, track-day tyres, wildly stiffer springs and iron-fisted dampers, the Supersport R is as a dart to a paper plane.
It is so much more precise, quick witted and agile that it offers the skilled driver on the right road (or, ideally, track) an experience quite beyond the imaginings of anyone who’d only ever driven an older car. Here the difference is between a recreational thing of fun and a deadly serious road weapon.