THE most enduring gag of the BBC’s self-lampooning show, “W1A”, involves the corporation’s fumbling “head of values” grappling with his folding Brompton bike as he arrives at Broadcasting House. Such is the way in which everyday artefacts are transformed into icons of popular culture.

Naturally, there is no fumbling down at the Brompton factory in Brentford, in west London. Lorne Vary, the chief financial officer of the bicycle-maker, shows how he can flip open the bike to make it ready to use in seven seconds flat. A growing army of enthusiasts see the virtues of a Brompton. The company is likely to sell a record 48,000 bikes this year and will soon move to a new factory, doubling its floor space. Turnover, at about £30m ($46m), has been growing by 16% year-on-year, says Mr Vary. Brompton hopes to double sales by 2021.

Brompton is already the country’s largest bike manufacturer, yet the company did not make them on a large scale until the early 2000s. Its rise happened against a backdrop of the almost complete collapse of Britain’s bicycle industry, once a world leader. Raleigh, the most famous volume bike-maker, based in Nottingham, had moved all its production to low-cost Asia by 2002. Now the vast majority of the 3.25m bikes sold in Britain annually are made abroad.

Brompton has bucked this trend by carving out a niche as a producer of high-end, handmade folding bikes with global appeal. The bikes are pricey, but every steel frame is fitted together using brazing rather than welding. The company makes much of its “Made in London tag”, as British craftsmanship is still valued overseas. About 80% of its bikes go abroad now, where Koreans, Japanese and others cherish them as fashion accessories as much as modes of transport.

All these countries suffer from clogged roads, too, making them good homes for the car-dodging Brompton. The domestic market should remain buoyant: one research firm has just declared London the most congested city in Europe.

Britain’s few other remaining bike-makers have survived using similar tactics. Pashley, based in Stratford-upon-Avon, has been making classic bikes, often seen in advertisements, since 1926. The company suffered a grave blow when the Royal Mail started phasing out its large fleet of Pashley bikes in 2010. It now sells about 10,000 units a year.

The brand is all about old-world heritage. Adrian Williams, Pashley’s boss, describes his products as “beautiful and useful”. Like Brompton, the firm is export-focused, selling to over 50 countries, mainly in Asia. Moulton, another brand, also sells well in the Far East.

However hard they pedal, these companies will struggle to make significant inroads into the British market. More Britons cycle than ever, partly encouraged by recent successes at the Olympics and in the Tour de France. Some British firms make components, a business that Mr Williams is getting into and where he expects to do well. But with costs in Asia still considerably lower, the vast majority of Britain’s bikes will continue to be made abroad.