Will Butler-Adams jumps on a Brompton and races off towards some industrial sheds at a rapid pace, almost as fast as he is talking. The engineer, who has been the chief executive of the British folding bikes firm for 14 years after joining 20 years ago, is enthusing about its new marketing, testing, spares and refurbishment facilities, which opened near its headquarters in Greenford, west London, last year.

Inside the rather dull grey sheds is an array of colourful bikes, some being “tortured” in testing tanks or waiting patiently to be fixed in a wall of cubicles – the physical manifestation of the more exciting rapid expansion of the brand during the pandemic.

The number of Bromptons sold rose by a third to 93,000 in the year to March as city-dwellers around the world turned to two wheels as a way to stay healthy and avoid potential infection on crowded public transport. That came after a strong year in the previous 12 months when pre-tax profits soared 60% to £9.6m and the company paid out more than £1m to its shareholders – who still include the founder, Andrew Ritchie, who designed the bike in his shed in 1975.

The group now employs 800 people worldwide, including 650 at its UK manufacturing base in Greenford, up from about 400 five years ago. Together they pump out 100,000 bikes a year from one shift – or about 600 a day – all overseen by AI technology that helps workers choose which frame to assemble next.

The spacious, airy facility is responsible for making 70% of the bike’s parts and assembling them. Brompton is one of just two commercial-scale bike makers left in the UK, the other being Pashley.

While sales of most bikes are expected to fall in the UK this year, as the pandemic boom for leisure cycling reverses, Butler-Adams expects Brompton’s sales to continue to grow as cities around the world promote active travel as a way to fight climate change, lower costs for citizens and improve health. In preparation, the company is seeking planning permission for a new factory on stilts in Ashford, Kent, with the ultimate aim of making 200,000 bikes a year.

Butler-Adams joined Brompton after a conversation with its then chairman on a bus persuaded him to leave aside plans for an MBA after working at ICI. He is so passionate about the need to encourage others to work on solving real-world problems such as climate change that he has written a book, The Brompton: Engineering for Change, about his philosophy and the development of the folding bike.

They are not cheap. Starting from £850 for a basic model and rising to £3,970 for a four-speed, super-lightweight titanium version, one might expect such luxuries to be set aside amid a probable recession and cost of living crisis. But Butler-Adams insists his bikes remain affordable – in the same way as a car – as they can last decades, save time and money, and improve health.

“If it adds value to your life it is a good investment and lasts 15 to 30 years. How many products can do that? It is good value not because it is cheap but because it is so bloody good,” he says.

“[Elon Musk’s] SpaceX may be doing amazing things with rockets but the bicycle is by a long chalk the most efficient mode of transport.”

China is Brompton’s fastest growing market, as the country turns back to bicycles in its cities, with Shanghai building new cycle lanes. “We are in it to change how people live in a city. If the bike is not relevant now then when is it?” says Butler-Adams.

READ RELATED: Lightfoot's plan to sue Chicago's gangs has stalled

“You can see what’s happening on a global scale. Even in the US, [which is used to] gas guzzling, they are shifting and the younger generation are not getting a driving licence.

“Cities are facing up to the need to change and put humans and families at their heart. Think how many cars are taking up space, how much that real estate is worth to people.”

He says that the popularity of electric scooters may well be paving the way for younger people to embrace cycling in a way their parents have found harder. “From scooter to bike you are 90% of the way there. Getting someone out of the bus or car is a much bigger step,” he says.

Still, the short term may feel like an uphill slog for Brompton after some free-wheeling sales and profit rises for a couple of years.

Costs are up about 10% across the board – from steel to labour – and not all of this can be passed on to customers, putting pressure on profit margins. Sales of its electric bikes are also rather slower than hoped after hold-ups on key parts, such as motors and batteries, at the height of the pandemic.

While sales of the ebikes have doubled to 12,000 since the launch year in 2019, Butler-Adams admits they are likely to make up less than 40% of sales, from hopes of half, as the extra weight of the battery-operated version has cancelled out Brompton’s USP – the ease of carrying the bike on public transport.

Brompton has meanwhile invested £700,000 in robotics to try to make its UK manufacturing even more efficient and piled more into research and innovation. For example, the company is developing super-light titanium bikes – just 2,500 of which will be made this year – in partnership with the Sheffield-based specialist CW Fletcher. That has put the company into debt for the first time in 20 years, just as interest rates are on the rise.

Butler-Adams adds that Brexit has also been “across the board negative” for Brompton, adding costs and bureaucracy and generally reducing efficiency. This year is the first time that workers have not seen their pay rise in line with the cost of living as Butler-Adams tries to avoid embedding inflation.

The price of Brompton’s bikes is set to rise by about 5% in October, following a similar increase last year. Butler-Adams says the company is sharing the pain of cost rises with its customers.

But he sees Brompton’s focus on quality, producing an item which will last decades with a bit of love and tinkering, as playing to a general shift towards buying fewer but better goods that will last.

Butler-Adams says: “We have got to buy less stuff and we need it to be more efficient. The bicycle is the way forward.”