Sources

Where the facts come from

Every factual claim on this site links to its source. This is the full list.

How we checked

Each fact was written in our own words alongside its source. Our build script stores the text of every source and, for each fact, checks that the key words and figures really appear in it. 185 of 185 checks passed when this site was last built (10 November 2026). Where we couldn’t find a named source saying something, we left it out. Where good sources disagree, we say so and give both.

Where sources differ

• The motor’s origin. Polymotor, an Italian subsidiary of Philips, with aircraft and marine work (Sinclair press kit); first meant for a lorry’s cooling fan (Hagerty UK, 2025); a modified washing machine motor (Adamson and Kennedy; the Guardian, 1985 and 2021, which in 2021 calls it a Hoover motor).
• Gearbox and axle. Mikron UK gearbox and Torrington axle (press kit) or provided by Lotus (Hagerty UK, 2025).
• The designer’s name. Guy Desbarats (press kit) or Gus Desbarats (Hagerty UK, BBC Radio 5 Live).
• Tony Rogers’s hiring. 1979 (Hagerty UK) or early 1980 (Adamson and Kennedy).
• Sinclair Vehicles’ start. Formed in March 1983 (Hagerty UK); Sinclair Vehicles Ltd established in February 1984 (press kit).
• Money. £12 million raised (Hagerty UK); £8.6 million start-up money and £5.9 million in loans (Adamson and Kennedy); £7 million invested (Sinclair Research spokeswoman, via Sinclair User).
• Battery. 35 Ah (press kit) or 36 Ah (c5owners.com).
• Range. Up to 20 miles (press kit), 24 (National Motor Museum), 18.7 (BBC Future), 11 to 25 (the Guardian, 1985), a typical 10 and 6.5 on a cold day (the AA, via Adamson and Kennedy).
• Weight. 99 lb (Sinclair User), 66 lb basic (the Guardian, 1985), 44 kg and 79 kg (Science Museum Group), 30 kg (Museum Wales).
• Built before launch. More than 2,000 (press kit) or some 2,500 (the Guardian, 1985).
• First 1,000 sales. In the first week (Sinclair’s spokesman, via Sinclair User) or four weeks after launch (Adamson and Kennedy).
• Production cut. Halted on 29 March 1985 and resumed at 10 per cent (Hagerty UK); stopped for three weeks, then cut by 95 per cent (Adamson and Kennedy).
• Built in total. 14,000 (Science Museum Group), about 12,000 by August 1985 (RCAHMW), around 15,000 (Sam Rowell, via Hagerty UK).
• Sold. 4,500 (Science Museum Group), fewer than 9,000 by the end of 1985 (National Motor Museum), 17,000 (BBC Radio 5 Live), fewer than 17,000 (Planet Sinclair), a few thousand (the Guardian, 2021).
• The Netherlands. Not suitable in its present form (Adamson and Kennedy) or banned outright (Planet Sinclair).
• Museum weight and range. Museum Wales’s online record gives a weight of 30 kg. We could not read its fuller description, so we have not used it.

All sources (24)

• Planet Sinclair: Ian Adamson and Richard Kennedy, The Machine Stopped (1986) (36 facts)
• Sinclair Vehicles: C5 launch press kit, 10 January 1985 (scanned PDF, Sinclair QL Preservation Project) (36 facts)
• Sinclair User: Chris Bourne, Pedal-power behind the hi-tech trike (March 1985) (16 facts)
• Hagerty UK: Antony Ingram, Freeze Frame: the Sinclair C5 experiment fails (March 2021) (13 facts)
• Hagerty UK: Adam Sloman, The Sinclair C5: turning 40 at FOTU (June 2025) (12 facts)
• Transport and Road Research Laboratory: I D Neilson and J S Armour, Research Report 55 on the Sinclair C5 electrically assisted pedal tricycle (1985, PDF) (10 facts)
• The Guardian: Stephen Bates, Sir Clive Sinclair obituary (September 2021) (8 facts)
• The Guardian archive: Roy Harry and Peter Large, Sinclair C5 electric trike goes on sale (11 January 1985) (7 facts)
• BBC Future: Jack Stewart, Was the Sinclair C5 30 years too early? (December 2014) (6 facts)
• Royal Commission on the Ancient and Historical Monuments of Wales: The Sinclair C5 and Merthyr Tydfil (2021) (6 facts)
• Sinclair User: Sinclair calls in the receivers (news, issue 45, late 1985) (5 facts)
• Alexandra Palace: 40 years of the Sinclair C5 (January 2025) (4 facts)
• BBC Radio 5 Live: Why did ‘ahead of its time’ Sinclair C5 fail to succeed? (January 2015) (3 facts)
• Planet Sinclair: Sinclair C5 (3 facts)
• Science Museum Group Collection: Sinclair C5 electric vehicle, object Y1986.152 (3 facts)
• The Independent: Sam Coates, Whatever happened to the Sinclair C5? (2 November 1996; transcription on Planet Sinclair, archived copy) (3 facts)
• c5owners.com: Sinclair C5 history and timeline (3 facts)
• Amgueddfa Cymru – Museum Wales: Sinclair C5, item 86.189I (2 facts)
• Hansard: Sinclair C5, Commons written answer, 28 January 1985 (2 facts)
• National Motor Museum, Beaulieu: Sinclair C5 (2 facts)
• legislation.gov.uk: The Electrically Assisted Pedal Cycles Regulations 1983 (SI 1983/1168), as made (2 facts)
• Hansard: Electrically assisted cycles, Commons written answer, 4 February 1985 (1 fact)
• Science Museum Group Collection: Sinclair C5 electric vehicle, object Y2005.124.1 (1 fact)
• legislation.gov.uk: Explanatory Memorandum to the Electrically Assisted Pedal Cycles (Amendment) Regulations 2015 (PDF) (1 fact)