The A-bike is a folding bicycle released by Sir Clive Sinclair in the United Kingdom on 12 July 2006. It was designed by Hong Kong design agency Daka, in collaboration with Sinclair Research, over a 5-year period. It was announced to the public in 2004. Clive Sinclair envisioned the A-bike, and Alex Kalogroulis was the main designer. It weighs 5.7 kilograms (13 lb) and folds to 67×30×16 centimetres (26.4×11.8×6.3 in), small enough to fit in a rucksack. The first version had 6-inch (15 cm) wheels, which was increased to 8 inches (20 cm) in later models. In 2015, an electric version, the A-Bike Electric, was introduced to the public as part of a Kickstarter campaign.