page_title: Sinclair C5
section_title: Development and design of the C5
hierarchical_section_title: Sinclair C5 / History / Development and design of the C5
caption_attribution_description: English: Sinclair C5 motor and left wheel
context_page_description: The Sinclair C5 is a small one-person battery electric velomobile, technically an "electrically assisted pedal cycle". It was the culmination of Sir Clive Sinclair's long-running interest in electric vehicles. Although widely described as an "electric car", Sinclair characterised it as a "vehicle, not a car".
  Sinclair had become one of the UK's best-known millionaires, and earned a knighthood, on the back of the highly successful Sinclair Research range of home computers in the early 1980s. He hoped to repeat his success in the electric vehicle market, which he saw as ripe for a new approach. The C5 emerged from an earlier project to produce a small electric car called the C1. After a change in the law, prompted by lobbying from bicycle manufacturers, Sinclair developed the C5 as an electrically powered tricycle with a polypropylene body and a chassis designed by Lotus Cars. It was intended to be the first in a series of increasingly ambitious electric vehicles, but the development of the follow-up C10 and C15 models never progressed further than the drawing board.
context_section_description: With Sinclair's new specifications in hand, Ogle worked on a three-wheeled design dubbed the C5, which bore similarities with the earlier three-wheeled Bond Bug – another Ogle design. The vehicle's handlebar steering was the brainchild of Wood Rogers, who decided at the outset that a steering wheel would not be practicable as it would make it impossible for a driver to get in and out easily – a serious safety disadvantage. He comments that "putting the bars at the driver's sides made it easy to steer and felt very natural". A prototype was presented to 63 families in the A, B, C1 and C2 demographic groups in suburban and town environments to determine that the controls were correctly positioned; this was the only external research carried out on the C5. In the autumn of 1983, Wills brought in Lotus Cars to finish the vehicle's detailing, build prototypes and test rigs, carry out testing and take forward the programme to production. The development of the C5 took place over 19 months in conditions of great secrecy, with testing carried out at the Motor Industry Research Association's proving ground in Leicestershire.
  Further aerodynamic refinements were carried out in Exeter with the development of new body shells which produced further reductions in the vehicle's drag. However, it was felt that something was lacking in the design and a 23-year-old industrial designer, Gus Desbarats, was brought in to refine the shell's appearance. He had won a Sinclair-sponsored electric vehicle design competition at the Royal College of Art and was hired on his graduation to set up an in-house car design studio at Sinclair's Metalab in Cambridge, of which he became the first employee. It was not only Desbarats' first project but, as he later said, "day one of my working life", when he turned up at Sinclair's premises. He was taken aback when he saw the C5 for the first time, as he had been expecting a "proper" electric car. He said later that he thought "the concept looked futuristic but was short on practicality. There were no instruments, nowhere to put anything and no security features." Desbarats told Sinclair that the design would have to be redone from scratch, "asking what we were doing about visibility, rear view mirrors, range indications ...". It was far too late for this, however; all the key design decisions had already been made. Desbarats told Sinclair that he would need four months to revisit the design and was given eight weeks instead. He created the styling that was used for the final production model of the C5, with wheel trims and a small luggage compartment being added subsequently. Desbarats was also responsible for the creation of the High-Vis Mast accessory, as he felt uncomfortable being so close to the ground with other drivers potentially not being able to see him. He later described his contribution as "convert[ing] an ugly pointless device into a prettier, safer, and more usable pointless device".
  The chassis of the C5 consists of two identical metal pressings which are joined at top and bottom with a closing plate at the rear. It lacks a separate suspension system, instead relying on the chassis structure having enough torsional flex. Its motor was produced in Italy by Polymotor, a subsidiary of the Dutch company Philips. Although it was later famously said that the C5 was powered by a washing machine motor, the motor was in fact developed from a design produced to drive a truck cooling fan. Lotus provided the gearbox and a rear axle based on a design for car steering columns. The C5's electronics were produced by MetaLab, a Sinclair spin-off. The wheels were assembled from tyres made in Taiwan and wheels from Italy. Oldham Batteries provided a lead-acid battery developed for Sinclair that could manage more than the 300 charge-discharge cycles that had originally been specified.
  The bodywork was made from two injection-moulded polypropylene shells supplied by three manufacturers; J.J. Harvey of Manchester made the moulds, Linpac provided the shells, and ICI supplied the raw material. According to Rodney Dal
caption: The C5's electric motor, which drives the left-hand rear wheel
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