Caterham Seven: 50 years of lightweight thrills

By Simon Hucknall

| 7 Feb 2024

Classic & Sports Car – Caterham Seven: 50 years of lightweight thrills

Fast, fun, light and simple: the Caterham Seven, doyen of the kit-car market and grassroots motorsport, has reached its half-century.

Few cars have been able to provide the Seven’s purity of purpose, no matter which engine, chassis or level of trim it has been equipped with.

The Seven’s pared-down weight has always been key to that appeal – in its most basic form, today’s smallest-engined model is arguably the world’s lightest production car, tipping the scales at a sylphlike 440kg.

Caterham acquired the rights to the Lotus Seven design in 1973

And the Caterham Super Seven’s Colin Chapman-inspired design – an aluminium-clad, two-seater, cigar-shaped body around a tubular steel chassis, with the engine up front and drive to the rear wheels, developed from the third iteration of the 1957 original – has always embodied the Lotus founder’s core tenet: ‘Simplify, then add lightness.’

With us at Bicester Heritage’s test track are (funnily enough) seven of the most significant Sevens built across the past 50 years, ranging from a famous ’70s track star, via a 0-100mph-0 record-holder to a humble 1.4-litre K-series-powered entry model.

Together, they tell an incredible story of survival against the odds.

The Caterham Seven Twin Cam’s Lotus engine makes 160bhp or so, and thrives on revs

In 1973, those odds were small. After the UK joined the European Economic Community at the start of the year, the Purchase Tax loophole gifted to impecunious enthusiasts prepared to build their own Lotus Sevens was abolished in favour of mandatory VAT on all vehicles, including those built from kits.

Colin Chapman no longer wanted Lotus to be associated with car kits, so the change in regulations gave him the perfect excuse to ditch the Seven, by then in Series 4 guise, after 15 years of production.

Caterham Cars was Lotus’ sole remaining UK Seven agent, so it was perhaps inevitable that founder Graham Nearn purchased the model’s rights from the Hethel parent company.

The Caterham Seven Twin Cam’s Minimalist cockpit has the bare essentials (left); the Twin Cam is the earliest car in our set, as its live-axle chassis reveals

When Caterham recommenced S4 production, however, the new model’s carried-over boxy styling won few fans and, by 1974, Seven Cars Limited (as the company was then known) had reverted to the 1968-’70 Series 3 design.

While the cost benefit of building your own Seven diminished once VAT was imposed, the premium for a Caterham-built car still encouraged plenty of DiY assemblies, but that changed around the turn of the millennium, as Simon Lambert, Caterham’s chief motorsport and technical officer, recalls: “When I joined the company in 2000, around 80% of buyers still built cars from kits.

“Now it’s the reverse of that – people don’t want to tinker with cars any more.”

The Caterham Seven Twin Cam is sweet to drive, but the unsilenced exhaust means it’s hardly stealthy

Part of this, Simon says, has been down to tightened regulations for kit-built cars since 1998, along with the added complexity of installing modern engines.

None of which would have applied to James Whiting’s 1977 Caterham Seven Twin Cam.

James, whose marque-specialist business has been servicing and modifying these models since the car was new, was one of Caterham’s competition pioneers and the first service agent appointed by Graham Nearn.

When new, this Seven, with its Lotus Twin Cam – now displacing 1650cc and producing around 160bhp – sat above the basic Seven GT with its choice of Ford 1300 or 1600 crossflow engines.

Based on the Ford BDA engine, the Caterham Seven HPC 1700’s 1699cc ‘four’ makes 170bhp

Sponsored by Caterham from 1978, James campaigned the car successfully in sprints, drag races such as the Brighton Speed Trials, and latterly 750 Motor Club events.

Initially, though, racing was off the menu due to the RAC banning the Seven from production-car championships – prompting Nearn to produce T-shirts printed with: ‘Caterham Seven – too fast to race.’

The ban, ultimately lifted, was the catalyst for Caterham’s own one-make series, which after many iterations still exists today.

The uncompromising Caterham Seven HPC 1700 demands serious focus, hence owners had to complete a training course before purchase

Objectively, James’ Twin Cam – the only car here from the first decade of production – is a world apart from the other models.

Looking wonderfully period in its Martini-style livery, which it has worn since 1981, it sits on Compomotive alloys with balloon-like 205/50 14in radial tyres.

You sit low in the sparsest of cockpits, with naked aluminium covering the footwells and gear tunnel, and two aeroscreens perched above the dash.

The main dials are for oil pressure and temperature, and there’s no speedo.

The Caterham Seven HPC 1700 has the spartan interior of a thinly disguised racing car

This is the car’s first outing for 30 years, so I’m respectful.

Fire up, and everyone in Bicester’s paddock turns around: with almost no baffles, its bark is unashamedly loud.

It needs revs, too: little happens below 3000rpm, such is the profile of the cam and the thirst of the twin Weber 45s, but it steers and rides so sweetly that you’re in awe.

It’s not that fast (although I’m told I could have tried harder), but its seemingly perfect balance is set to be a common feature across all the cars here today.

The Cosworth-tuned BDR unit uses a 1699cc crossflow block

We can do scant justice to the Seven’s myriad powertrain and chassis variations over the years – setting aside the fact that most cars have been upgraded or modified along the way – but suffice to say that, until Vauxhall and Rover engines were employed from 1990, the Lotus Twin Cam and a plethora of Ford units, including the 1600 Kent and CVH engines, were the mainstays of the Seven range.

It is an altogether more bespoke Ford-based engine, though, that powers the rare and very desirable HPC 1700.

In effect a Ford BDA unit (with a 1699cc crossflow block and Cosworth cylinder head), it went under the ‘BDR’ moniker for Caterham and made 170bhp – or 288bhp per tonne.

‘In many ways the Classic Sprint 1600 is the archetypal Caterham. The chassis does a first-class job of signposting the car’s responses’

‘HPC’ came from the John Lyons High Performance Course that buyers had to go on before being allowed to order one.

Caterham stated: ‘A fast car needs a special kind of skill that can only be fully developed with training.’

At £12,000, it was the most expensive Caterham yet when it was launched in 1986.

Nigel Blandin has now owned his HPC for 20 years, with his passion for Caterhams inspired by the James Whiting car we’ve just driven.

The Caterham Seven Classic Sprint 1600 uses sidedraught Webers to help the Kent engine breathe (left); the Sprint’s crossflow unit makes 100bhp

“I love the challenge of a Seven’s engineering,” he explains. “You have to work with it, and understand it.”

On track, the HPC’s Alcantara-trimmed wheel jiggling in your grasp, the enlarged 1835cc BDR is hugely tractable low down, but truly explosive in its upper reaches.

I’m told 9500rpm is safe, but by the time we’ve hit 7500rpm, there’s no track left.

The official 0-60mph time of 5 secs barely represents how frighteningly rapid this car is.

The SE pack, as added to this Classic Sprint 1600, included creature comforts such as a windscreen and a fuel gauge

Powering through Bicester’s fast and technical bends, the steering is tactile, quick, and perfectly mated to a chassis that’s so user-friendly you simply nudge the wheel towards an apex then steer through on the throttle, exercising the limited-slip diff either in ‘showboat’ mode or a neat four-wheel drift.

Even the occasional kerb-bounce does little to deflect the composure.

But Caterham’s heartland has always been accessible performance, and Jon Symons’ smart red Classic represents that to a tee.

The Jonathan Palmer-developed Caterham Seven JPE packs a 2-litre, BTCC-honed punch

Launched at the 1992 British Motor Show, the Classic cost an enticing £7450, with the aim of broadening the Seven’s appeal still further.

Its equipment list was so pared-down that it did without a fuel gauge, heater and a full windscreen.

But, like many Classics, Jon’s car was ordered with the SE package, adding a full instrument set, weather gear, a windscreen and alloy wheels.

It was also fitted with the 1600 Sprint crossflow engine rather than the lower-powered 1600GT unit, the addition of twin 40DCOE sidedraught carburettors bumping output from 84 to 100bhp at 6000rpm.

The record-breaking Caterham Seven JPE achieved a 0-100mph-0 time of just 12.6 secs

Along with James’ 1977 Seven Twin Cam, this Classic Sprint 1600’s performance lags behind the rest of ‘our’ cars.

It also feels the most road-friendly Caterham here, with its softer set-up offering a supple ride along with more body movement compared to the focused HPC.

Ensconced in the snug, leather-trimmed and carpeted cabin, facing a full complement of instruments, this would be the Caterham of choice for longer road trips.

The dayglow-yellow instruments make sure this Caterham Seven JPE stands out (left); the JPE’s 250bhp Vauxhall ‘red-top’ was developed by Swindon Racing Engines

In many ways it’s the archetypal Caterham: a live axle, a slick and peachy five-speed gearshift (arguably the best here), and a chassis that in general is benign and does a first-class job of signposting the car’s responses to your subtlest inputs.

Up the ante on track and the Classic Sprint’s mediocre performance (relatively speaking) results in a surfeit of grip over grunt, so a bold cornering approach is needed to achieve those period car-magazine drift shots.

But, as with all the cars here today, it never runs away from you, no matter how hard you provoke it.

The Caterham Seven JPE is tractable low down, but its manic peak power output is constrained by a tightly balanced, track-focused chassis

Talking to ex-Formula One driver Jonathan Palmer, who helped develop the JPE model we’re about to drive, he sums up perfectly the Caterham’s appeal: “It’s a Minimalist car – exhilarating and quick.

“You feel immediately when it starts to slide, because you’re sitting over the rear axle.

“The driving controls are straightforward, so people feel instantly familiar with them.”

Having started using Sevens at his PalmerSport track facility in 1992, Jonathan developed the JPE – or ‘Jonathan Palmer Evolution’ – with Caterham.

The Caterham Seven Roadsport Limited Edition 1.4 Supersport swapped the Ford 1.6 Supersprint engine for an uprated Rover K-series unit

It was a no-expense-spared project, with the Swindon Racing Engines 1998cc fuel-injected Vauxhall ‘red-top’ unit akin to those used in Vauxhall’s BTCC cars.

Producing 250bhp at 7750rpm, the engine alone was rumoured to cost £13,000 and in the JPE it generated 472bhp per tonne, meaning it could accelerate to 60mph from rest in a breathtaking 3.46 secs.

It went on to post a World Record 0-100mph-0 time of 12.6 secs.

The Roadsport’s more road-biased geometry lends it an accessible lightness at the expense of outright cornering grip at circuit pace

Dave Gwatkin has owned his stock JPE for three years.

With its subtle grey paintwork and contrasting dayglow-yellow badging and instruments, the car stands out even in this company.

Dymag magnesium wheels plus carbonfibre cycle wings and seats set it apart still further, as does the carbonfibre dressing the dash and gearknob.

Press the start button and the straight-cut gears of the Quaife ’box immediately make themselves heard as you accelerate away.

The Caterham Seven Roadsport Limited Edition has a removable Momo steering wheel

Subjectively, it’s the second-quickest car here, with surprisingly potent low-down tractability.

But when you think you’ve reached the JPE’s performance zenith, there’s more – and more.

The Vauxhall unit’s initial, guttural bark morphs into a frenzied scream at higher revs.

It sounds and feels ever so slightly unhinged as you push harder, until you realise that yet another layer of chassis brilliance has now come into play.

This Caterham Seven’s peaky 1.4-litre Rover K-series engine makes 128bhp and spins to 7600rpm

With no understeer, tighter body control than any of the other cars and a circuit-friendly high-speed balance, the JPE is inch-perfect and something to behold on this fast and technical course.

Contrasts don’t come much greater than swapping from the JPE to Andy O’Hara’s 1996 Roadsport Limited Edition.

Owned since 2018, this car is fitted with a Supersport engine – an uprated 1.4-litre Rover K-series.

Originally only available in 105bhp form for the standard Roadsport, the unit received reprofiled cams, a larger-bore inlet manifold and a remapped ECU to make 128bhp and increase redline revs to 7600rpm.

The Caterham Seven CSR200 is rapid but manageable

The development was crucial to Caterham, because it needed to replace the ageing Ford 1.6 Supersprint engine.

Also standard on the Roadsport Limited Edition were 14in Minilite wheels, a removable Momo steering wheel and gearshift indicators.

This is another Caterham that is clearly more road-biased, with Andy admitting that the car rarely ventures on track.

Its less aggressive steering and suspension geometry makes it feel lighter and more agile than the high-powered Sevens, although at 544kg there’s little difference in kerbweight.

The Caterham Seven CSR200 sports a flexible Ford Duratec engine

Body movements are marked versus the other cars, but you can imagine the liveliness of its chassis being entertaining on the road without needing to carry any great speed.

There is significantly less grip in corners, and you soon adopt a throttle-off approach to neutralise the inherent understeer.

The little Rover K-series is also quite peaky in this guise, so you need to work it hard to optimise the car’s performance.

When our penultimate Seven, the CSR200, arrived in 2005, it represented the biggest technical change in the model’s 32-year history.

The Caterham Seven CSR200 has the longer SV chassis, which better suits taller drivers

Using the SV’s 110mm wider, 150mm longer chassis, a boon for taller drivers, the CSR mirrored many of the modifications made for the SV-R race car.

Inboard pushrod front suspension was employed for less unsprung mass, and the cleaner airflow contributed to a 50% reduction in high-speed lift, while the front track also grew by 50mm, offering greater stability and grip.

For the first time, the Seven gained an independent rear end, with double wishbones and coils, which in turn allowed the chassis’ tubing to be strengthened, resulting in a 25% leap in torsional stiffness.

The Caterham Seven CSR200’s exhaust is relatively quiet (left); Formula One-style front suspension

Mechanically, Caterham’s ‘dirty’ Rover-based XPower engine was replaced by a cleaner 2.3-litre, 16-valve Cosworth-tuned Ford Duratec ‘four’, making, as the name suggests, 200PS (197bhp).

A more powerful CSR260 version was also available.

Ben Ferrey’s CSR, which he has owned for 18 months, shows how much scope there was at the time to bring the Seven into the 21st century without moving away from its essential ethos.

‘You balance the thrill of nailing the throttle against the pain inflicted on your ears: the R500 is savage in every respect’

I’m a mere 5ft 7in, so only just reach the pedals in the longer chassis, even with the seat moved forward.

On the track, the CSR is refined and perhaps the most undemanding of all the Sevens to drive.

Its Duratec motor is smooth, flexible and relatively quiet, save the odd fruity ‘pop-pop’ on the overrun, and the six-speed ’box’s gearing is taller than that of most the others.

It’s still unarguably quick, but the CSR’s markedly higher grip levels, lower-geared steering and tighter overall body control make it the least frenetic Seven to drive.

At its launch, the maximum-attack Caterham Superlight R500 represented peak Seven

Which is not an accusation you’d level at our final Seven, the Superlight R500.

At launch in 2008, this was the performance pinnacle of the Seven series, sitting above the 120, 150, 300 and 400 models in the Superlight range.

Caterham replaced the previous K-series VHPD-powered R500 and once again used the Duratec engine, this time 1999cc with a cylinder head fettled by ex-F1 engineer Simon Armstrong and the addition of roller-barrel throttle bodies to produce a spectacular 263bhp at 8500rpm – and, more importantly, a power-to-weight ratio of 520bhp per tonne.

True to its ‘Superlight’ moniker, the R500 gained a lighter-weight chassis mated to a carbonfibre nose cone and cycle wings to achieve a kerbweight of just 506kg.

The Caterham Seven Superlight R500’s tuned Duratec engine gives 263bhp

Optional kit included a Caterham Motorsport-engineered six-speed sequential gearbox that cost an eye-watering £2950.

And it’s that transmission that we’re just coming to terms with in this Caterham Cars-owned R500, the very car in which ‘The Stig’ achieved that barely-believable 1 min 17.9 secs lap around the Top Gear track in 2008, beating the Bugatti Veyron 16.4’s time.

Sitting in the unpadded carbon-Kevlar driver’s seat, you face a simple Stack digital instrument panel and not much else.

Using the clutch to move away – it’s not needed for upchanges, when just a slight lift is required – the acceleration is vicious.

A focus on weight reduction helped the R500 to achieve 500bhp per tonne

With no insulation, the open cockpit heats up quickly, and you inwardly balance the thrill of nailing the throttle hard against the pain inflicted on your ears: the R500 is utterly savage in every respect.

Bash through the gears – back for upshifts, forwards for down – and beyond 7500rpm it gets a second wind all the way to 9000rpm.

At that point your commitment needs to be absolute, the more so because your vision is impaired by the carbonfibre ’screen and (as I’m told later) grip by this car running on 10-year-old rubber.

Yet, despite offering a huge surfeit of power over grip, the R500 remains just as exploitable and faithful to driver inputs as any other Seven.

Given the model’s lairy reputation, I can’t think of any better testament to the brilliance of Caterham’s diminutive legend.

Images: Max Edleston

Thanks to: Caterham Cars; James Whiting Sevens; Bicester Heritage; Richard Nichol, the Caterham & Lotus Seven Club

Factfiles

Caterham Seven Twin Cam

Sold/number built 1974-’83/313
Construction aluminium body with stressed panels, tubular steel chassis
Engine iron-block, alloy-head, dohc 1558cc ‘four’, twin Weber 40DCOE carburettors
Max power 126bhp @ 6500rpm
Max torque 113lb ft @ 5500rpm
Transmission four-speed manual, RWD
Suspension: front independent, by lower wishbones, anti-roll bar as upper wishbones rear live axle, A-frame, trailing links; coil springs, telescopic dampers f/r
Steering rack and pinion
Brakes discs front, drums rear
Length 11ft 1in (3380mm)
Width 5ft 2in (1575mm)
Height 3ft 8in (1115mm)
Wheelbase 7ft 3in (2225mm)
Weight 1102lb (500kg)
Mpg 20
0-60mph 7 secs (est)
Top speed 109mph
Price new £3700 (1977)
Price now £25,000*

Caterham HPC 1700

Sold/number built 1986-’95/62
Construction aluminium body with stressed panels, tubular steel chassis
Engine iron-block, alloy-head, dohc 1699cc ‘four’, twin Weber 45DCOE carburettors
Max power 170bhp @ 6500rpm
Max torque 140lb ft @ 5500rpm
Transmission five-speed manual, RWD via limited-slip differential
Suspension: front independent, by double wishbones rear de Dion axle, A-frame, radius arms, anti-roll bar; coil springs, telescopic dampers f/r
Steering rack and pinion
Brakes discs
Length 11ft 1in (3380mm)
Width 5ft 2in (1575mm)
Height 3ft 8in (1115mm)
Wheelbase 7ft 3in (2225mm)
Weight 1300lb (590kg)
Mpg n/a
0-60mph 5 secs (est)
Top speed 120mph
Price new £12,000 (1986)
Price now £25-35,000*

Caterham Classic Sprint 1600

Sold/number built 1992-’98/n/a
Construction aluminium body with stressed panels, tubular steel chassis
Engine all-iron, ohv 1598cc ‘four’, twin Weber 40DCOE carburettors
Max power 100bhp @ 6000rpm
Max torque 105lb ft @ 5200rpm
Transmission five-speed manual, RWD
Suspension: front independent, by lower wishbones, anti-roll bar as upper wishbones rear live axle; A-frame, coil springs, telescopic dampers f/r
Steering rack and pinion
Brakes discs front, drums rear
Length 11ft 1in (3380mm)
Width 5ft 2in (1575mm)
Height 3ft 8in (1115mm)
Wheelbase 7ft 3in (2225mm)
Weight 1200lb (625kg)
Mpg 34
0-60mph 6.5 secs (est)
Top speed 110mph (est)
Price new £7450 (1600GT)
Price now £10-15,000*

Caterham JPE

Sold/number built 1992-2001/53
Construction aluminium body with stressed panels, carbonfibre wings, tubular steel chassis
Engine iron-block, alloy-head, dohc 1998cc ‘four’, Weber Alpha electronic fuel injection
Max power 250bhp @ 7750rpm
Max torque 186lb ft @ 6250rpm
Transmission Quaife straight-cut five-speed manual, RWD
Suspension: front independent, by double wishbones rear de Dion axle, A-frame, radius arms, anti-roll bar; coil springs, telescopic dampers f/r
Steering rack and pinion
Brakes ventilated front, solid rear discs
Length 11ft 1in (3380mm)
Width 5ft 2in (1575mm)
Height 3ft 8in (1115mm)
Wheelbase 7ft 3in (2225mm)
Weight 1168lb (530kg)
Mpg n/a
0-60mph 3.46 secs
Top speed 150mph
Price new £37,000
Price now £40-50,000*

Caterham Roadsport Limited Edition 1.4 Supersport

Sold/number built 1996/n/a
Construction aluminium body with stressed panels, tubular steel chassis
Engine all-alloy, dohc 1397cc ‘four’, multi-point fuel injection
Max power 128bhp @ 7400rpm
Max torque 100lb ft @ 5000rpm
Transmission six-speed manual, RWD
Suspension: front independent, by double wishbones rear de Dion axle, A-frame, radius arms; coil springs, telescopic dampers f/r
Steering rack and pinion
Brakes discs
Length 11ft 1in (3380mm)
Width 5ft 2in (1575mm)
Height 3ft 8in (1115mm)
Wheelbase 7ft 3in (2225mm)
Weight 1200lb (544kg)
Mpg n/a
0-60mph 6 secs
Top speed 114mph
Price new n/a
Price now £14,500-15,500*

Caterham CSR200

Sold/number built 2005-’11/196 (est)
Construction aluminium body with stressed panels, tubular steel chassis
Engine all-alloy, dohc 2261cc 16v ‘four’, electronic fuel injection
Max power 197bhp @ 6000rpm
Max torque n/a
Transmission six-speed manual, RWD
Suspension independent, at front by double wishbones, coil springs with inboard pushrods, telescopic dampers rear double wishbones, coil-overs
Steering rack and pinion
Brakes discs
Length 12ft 6in (3530mm)
Width 5ft 6in (1685mm)
Height 3ft 8in (1115mm)
Wheelbase 7ft 6in (2305mm)
Weight 1267lb (575kg)
Mpg 27.5
0-60mph 3.7 secs
Top speed 140mph
Price new £31,000
Price now £33-35,000*

Caterham Superlight R500

Sold/number built 2008-’14/176
Construction aluminium and carbonfibre body with stressed panels, tubular steel chassis
Engine all-alloy, dohc 1999cc 16v ‘four’, electronic fuel injection with roller-barrel throttle bodies
Max power 263bhp @ 8500rpm
Max torque 177lb ft @ 7200rpm
Transmission six-speed sequential manual, RWD via limited-slip diff
Suspension: front independent, by double wishbones rear de Dion axle, A-frame, radius arms, anti-roll bar; coil springs, telescopic dampers f/r
Steering rack and pinion
Brakes discs
Length 10ft 2in (3100mm)
Width 5ft 2in (1575mm)
Height 3ft 8in (1115mm)
Wheelbase 7ft 3in (2225mm)
Weight 1115lb (506kg)
Mpg n/a
0-60mph 2.9 secs
Top speed 150mph
Price new £36,995
Price now £40-45,000*