Sinclair C5 major consumer organisations published sceptical evaluations. The Automobile Association questioned many of Sinclair's claims in a report published at the start of May. It found that the range of the vehicle was typically only about 10 miles (16 km) rather than the promised by Sinclair, and reported that the C5's battery ran flat after only on a cold day. The C5's running speed was more usually around than the claimed , while its running costs compared unfavourably to that of a petrol-driven Honda PX50 moped. The stability, general roadworthiness, and especially the safety of the C5 were questioned, and the
Sinclair Radionics was failing, Clive Sinclair took steps to ensure that he would be able to continue to pursue his commercial goals: in February 1975, he changed the name of Ablesdeal Ltd. (an off-the-shelf company he bought in September 1973, for just such an eventuality) to Westminster Mail Order Ltd.; this was changed to Sinclair Instrument Ltd. in August 1975. Finding it inconvenient to share control after the NEB became involved in Radionics, Sinclair encouraged Chris Curry, who had been working for Radionics since 1966, to leave and get Sinclair Instrument up and running. Sinclair Instrument developed the "Wrist Calculator" to generate