History of the Sinclair C5

• Clive Sinclair's interest in electric vehicles went back to a holiday job at Solartron in the late 1950s. In the early 1970s, at Sinclair Radionics, he had Chris Curry (later a co-founder of Acorn) look into EV motors, and they built a thin motor driving a child's scooter. Calculators then took priority.
• Late 1979: the C1. Sinclair hired a former Radionics engineer, Tony Wood Rogers, to study a one-person electric vehicle to replace the moped. He built a series of prototypes. The aim was a cheap, weatherproof runabout with a plastic body, at no more than about £500.
• 1982: development moved to the University of Exeter, where shells were tested in the wind tunnel. Ogle Design were brought in for styling, but they treated it as a car and the weight ballooned. The C1 was stopped in March 1983.
• March 1983: Sinclair sold about 10 % of Sinclair Research to institutions, raising £12 m, of which £8.3 m set up Sinclair Vehicles Ltd.
  • Barrie Wills, formerly of DeLorean, became managing director.
  • Head office moved to Coventry in 1984. Owners' literature gives Stanhope Road, Camberley, Surrey, and later Sinclair Vehicle Sales Ltd used the University of Warwick Science Park.
• August 1983: the Electrically Assisted Pedal Cycles Regulations 1983 came into force. They were lobbied for by bicycle makers such as Raleigh, after work by the Transport and Road Research Laboratory (TRRL). The rules allowed:
  • no licence, tax, insurance or helmet;
  • drivers from age 14;
  • max 60 kg for a tricycle;
  • a 250 W motor;
  • a 15 mph powered top speed.

Sinclair redesigned the project around the new class, and it became the C5. See Legislation.

• The handlebar-under-the-knees steering was Wood Rogers' idea, so drivers could get in and out easily. A prototype was shown to 63 families to check the control positions. This was the only external market research.
• Lotus Cars (Hethel/Wymondham, Norfolk) were brought in by Wills in autumn 1983. They did detail design, built the prototypes and test rigs, and ran the testing.
  • Lotus built 12–20 GRP-bodied prototypes, which were tested to destruction, and four GRP cars for brochure photography.
  • Testing included 24-hour tethered running rigs and a brake cycled 75 times a minute for two months. MIRA and British Aerospace facilities were also used.
  • Lotus designed the Y-frame chassis, the gearbox and the rear axle.
• About 100 people worked on the project over a concentrated 12-month development. Tooling was committed by mid-1984.
• Electrics: Perran Newman (Sinclair Research / MetaLab) and Peter Milner (Sinclair Vehicles) designed the electrical system, the motor protection and the “fuel gauge”. The ULA came from Ferranti and the control electronics were made by AB Electronics of Wales.
• Styling: Gus Desbarats, a 23-year-old Royal College of Art graduate and the first employee of Sinclair's in-house design studio, restyled the body in eight weeks. He also created the High-Vis Mast.
• Bicycle parts: JHF Cycles Distributors (Frank and Rosalie Clements) sourced the cycle parts. Wheels came from Italy, forks and pedals from Taiwan, and tyres from Vee Rubber in Thailand. The planned retail price at that stage was £199.99.
• Testing on the road:
  • Hill-descent and motor-protection tests took place at Prescott hill climb. During one descent a heat-softened front rim burst a tube, which led to a rear-drum heat plate and a change in front/rear brake balance.
  • A “traffic relationship exercise” was held on the TRRL Small Road System at Crowthorne on Sunday 2 December 1984, with about a dozen early-production C5s mixing with cars, cyclists and pedestrians. The participants included Barrie Wills, Gus Desbarats, Perran Newman, Peter Milner and Paul McVeigh. Early C5s had grey boot lids; the white ones came later, probably as a result of trials like this.
• Hoover was approached in spring 1983 by the Welsh Development Agency. It agreed to be principal subcontractor at its Merthyr Tydfil washing-machine works, attracted by Sinclair forecasts of 200,000–500,000 units a year.
  • Production was carried out in secret in building MP7.
  • Hoover trained its service engineers at its Doncaster training school (see Hoover Service Network).
• Full production started in November 1984. More than 2,500 had been built by early January 1985.

• The C5 was unveiled at Alexandra Palace, London, in snow and ice. Six C5s burst out of cardboard boxes, driven by women in grey and yellow.
• Price: £399 including VAT, plus £29 delivery, initially by mail order only. Sinclair promised a £3 m advertising campaign.
• The press day went badly. Many demonstration machines failed, batteries went flat, and motors overheated on the slopes. Reviews were dominated by safety worries about the low seating position among lorries and exhaust pipes, and by questions about practicality. The Engineer called it “a smashing big boy's toy”.
• About 20,000 members of the public tried it over the next two days, but fewer than 200 were sold at the event. Mail-order sales then picked up, reaching around 5,000 within four weeks. Sinclair's own figures are disputed.

• March 1985: the C5 reached shops. Sinclair hired teenagers to drive C5s around London and other cities.
• Production was halted for about three weeks over a fault in the plastic gearbox moulding, and restarted at about 10 % of the previous rate (about 100 a week). Over 3,000 unsold C5s piled up at Hoover.
• Export attempts failed. The Dutch authorities, for example, wanted better brakes, more reflectors and the High-Vis Mast as standard.
• May 1985: the AA report found the real range much lower than claimed, and questioned the stability, safety and running costs.
• June 1985: Which? had gearbox failures on all three of its test C5s and broken High-Vis Masts.
• July 1985: the Advertising Standards Authority ordered changes to the C5's speed and safety claims. About 8,000 had been sold by then.
• Retailers cut prices. Comet went to £259.90, and by year-end was selling a C5 with a full accessory set for £139.99.
• June 1985: Hoover issued a writ for over £1.5 m of unpaid debts.
• August 1985: production ended for good. The total built was about 12,000–14,000; sources differ.

• 19 September 1985: Sinclair Vehicles was renamed TPD Ltd. 15 October 1985: it went into receivership, with about £7.75 m of debts, about £7 m of them owed to Sir Clive. The receivers reported about 4,500 sold and 4,500 left in stock.
• The remaining stock was bought for about £75 each by Ellar (Surplus Goods) Ltd of Liverpool (director Maurice Levensohn). Ellar marketed the C5 as a “sophisticated toy” and reportedly sold nearly 7,000 at up to £700.
• Ellar's sister company Turbinecharm Ltd, at the same Allerton Road address, sold C5 spare parts by mail order at least until 1989–91. Parts lists survive.
• Adam Harper, who worked on C5 design, remained an authorised C5 dealer and servicer for decades. He set electric land-speed records in modified C5s, eventually reaching 150 mph.
• Follow-on vehicles were planned but never built:
  • C10: a two-seat city car, which existed as a mock-up.
  • C15: a three-seat car.
• Sir Clive's later electric transport included the Zike electric bike (1992), the Zeta cycle motor (1994) and the A-bike folding bicycle (2006). He died in September 2021.
• The C5 became a cult collectable. Enthusiast clubs and sites include C5owners.com (with a large Facebook group), C5Alive.co.uk and the older SinclairC5.com, run by Roy Woodward and the Sinclair C5 Enthusiasts. Owners still restore and modify C5s and 3D-print replacement parts.
• Museum examples include Amgueddfa Cymru – Museum Wales (a C5 plus a complete owner's pack, 1996.111), the Science Museum Group, the National Motor Museum at Beaulieu, the Lane Motor Museum (US), and others.

• Rodney Dale, The Sinclair Story (Duckworth, 1985).
• Ian Adamson and Richard Kennedy, Sinclair and the 'Sunrise' Technology (Penguin, 1986).
• Barrie Wills, two books on Sinclair Vehicles and the C5. Look for these by author name.
• Frank Clements, A Bike Ride Through My Life (an extract appears on c5owners.com).
• Wikipedia, “Sinclair C5”, which is well referenced.

• Wikipedia, “Sinclair C5” (accessed Oct 2026), and the sources it cites.
• The Engineer, 17 Jan 1985; Autocar, 16 Jan 1985; Twist & Go magazine C5 feature (c. 2005).
• c5owners.com: recollections by Perran Newman, Frank Clements and John Dunne; TRRL briefing memo of 29 Nov 1984; Turbinecharm and ESG price lists.
• Hoover C5 Service Engineer Training Notes (1984).
• Amgueddfa Cymru – Museum Wales object records.