They are the vehicle du jour of the green-thinking commuter and over the years have garnered such a cult following that people even race them.
But today Andrew Ritchie, the founder and creator of Brompton bikes has exited, presumably on his bike. Sources close to the company claim he had disagreed with the way the company was being run.
Andrew Ritchie designed the first Brompton in his flat in west London in 1975 and set up the company in 1976 and the bikes have always remained true to their original designs.
However an ambitious expansion strategy including the introduction of a vast palette of new colours, stand-alone stores in prime retail real estate and a high profile marketing campaign which included ex professional cyclist and TV pundit David Millar racing one on a Tour de France stage with co-host Ned Boulting, have proved too much.
Profits dipped 37 per cent last year to £2.1 million, according to its latest set of accounts.
"Brompton is Andrew's baby but he's been unhappy with certain aspects of how the company is developing. Things had started to upset him so he decided to step down from the board," a source told the Press Association.
Mr Ritchie continues to be the biggest shareholder of the company with around 18 per cent. The source added that he still "has a role at the firm".
Brompton is expanding into China, launching electric bicycles and moving to a new factory in Greenford, west London. Under the stewardship of Will Butler-Adams, chief executive, it earlier this year secured investment from serial entrepreneur and private equity boss Luke Johnson..
Since stepping down from Brompton's board, Mr Ritchie is thought to have set up his own design workshop.