The Brompton is a cult urban object, but if you’ve ever hauled one of the company’s elegant folding bikes up a set of Tube station stairs, you’ll be aware of how much serious engineering weighs.

Introduced in 1975 by inventor and company founder Andrew Ritchie, the company has grown slowly and steadily, and now sells around 70,000 bikes a year, in cities as far flung as Shanghai, New York and Singapore, with 15 flagship stores around the world. Urban cycling is still an expanding market, and Brompton’s unique folding mechanism makes it the ultimate and original last mile solution. 

 

Brompton T Line

The new Brompton T Line is being touted as the company’s lightest bike ever, with a total weight of 7.45kg. Given that the regular model starts at around 10kg, with electrified versions coming in even heavier, that’s a pretty impressive reduction.

It has taken the London-based company three years to refine the design of the T Line. From the outset, the focus was on shedding weight, which brings a huge number of benefits for the Brompton rider.

Detail of Brompton titanium folding bike

To achieve the 37 per cent reduction, the frame is made from titanium, corrosion-resistant, strong, ultra-light and relatively abundant, but also devilishly hard to work with. Yet before the first piece of metal was even cut, the design was fully computer modelled and simulated to optimise every millimetre of the frame’s structure.

Brompton’s team were on a hunt for every last superfluous gram, shaving down the frame and over 150 components without compromising the unique fold mechanism that is at the heart of the bike. 

Detail of new Brompton titanium folding bike

To achieve the right levels of quality, Brompton is working with Sheffield-based metalworkers CW Fletcher & Sons, specialists with 130 years of experience, including high precision work for the aviation and nuclear industry. Two different types of welding process are used at the dedicated new Brompton Fletcher facility, before the frames come down to London to be kitted out with the all-new componentry.

This includes a compact drivetrain with a carbon crankset, as well as a gear-ratio that’s been specifically tuned for urban riding. Other key details include a steel-armoured carbon seat post – and the T Line is the first bike in the world to have this feature – in order to withstand the wear of daily folding, unfolding, and riding. 

Brompton folding bike

The T Line is designed for riders and their luggage up to 110kg, with the drive system tested extensively in every kind of weather condition. The riding quality has also been carefully considered, with a one-piece carbon fork and wider carbon handlebars. At launch, there will be the T Line One specification – a minimal, single-speed machine designed for the purist – while the T Line Urban features the new compact gear system for more flexibility.

‘The only thing that has been carried over from our classic model is the brake system,’ says Brompton’s chief design and engineering officer, Will Carleysmith, ‘Everything else has been finessed, pared back, and upgraded.’ §