Brompton has redesigned its iconic folding bike to create its lightest version ever that – at 7.45kg – weighs a whopping 37% less than the original all-steel equivalent, “setting a new benchmark for folding bikes in lightness, ride performance and robustness” so Brompton says. 

Brompton T Line 4
Brompton T Line 4 (Image Credit: Farrelly Atkinson)

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The new lightweight titanium Brompton T Line is the result of three years of development and research, and is available in a single-speed or four-speed spec.

“At the new facility in Sheffield, the frame is precision-engineered in titanium, then orbital and tig-welded for strength,” says Brompton. 

Brompton_T Line_Welding 2
Brompton_T Line_Welding 2 (Image Credit: Farrelly Atkinson)

“The T Line is comparable to a carbon road bike, yet, it can be comfortably ridden by a 110kg rugby player and withstand the punishing impact of the city,” claims Brompton.

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The new titanium model features a patent-pending drivetrain that has been designed ground-up to sit inside the fold, as well as to be as light as possible.

Brompton T Line 7 (1)
Brompton T Line 7 (1) (Image Credit: Farrelly Atkinson)

The carbon crankset has been included to save weight and “give greater power transfer”, while the 60g derailleur is said to deliver smooth shifting in a small package. The T Line Urban model also comes with a new gear ratio – it is equipped with a 50T chainring and 11-13-15-18T sprockets. 

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Brompton has also used Tubolito’s S-Tubo lightweight 34g tubes for folding bikes, which have a reduced wall thickness to save weight over standard butyl tube options.  

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Brompton T Line 6
Brompton T Line 6 (Image Credit: Farrelly Atkinson)

Another one of Brompton’s big claims is that the new T Line is the first bike in the world with a steel-armoured carbon seat post.

“Ordinary carbon seat posts are stiff, strong and lightweight, but they can’t stand up to the daily use of a folding bike,” the brand notes. 

“Brompton’s design engineers have developed a new process to reinforce the limitations of carbon with 0.3mm steel armour. 

“The result is a superlight seat post that can take the abrasion of the fold, 110kg load and all-weather riding.”

Brompton T Line 8
Brompton T Line 8 (Image Credit: Farrelly Atkinson)

What else? Well, Brompton says it’s also managed to make this model faster to fold and easier to carry.

You’ve got new self-aligning hinges which, according to Brompton, are always “set-to-go”. Then there’s the spring-loaded handlebar catch that is said to click effortlessly, and an easy-grab carbon saddle with an integrated nose handle. 

Brompton T Line 5
Brompton T Line 5 (Image Credit: Farrelly Atkinson)

Perhaps leaving existing Brompton owners in a bit of a quandary (i.e. making every effort to persuade them to splash out on this new and improved version) Brompton boasts: “Nothing folds like this Brompton, not even other Bromptons.” 

We’re promised a seriously fun ride too: “Carbon cranks and cast Ti bottom bracket shift your power for a faster ride,” Brompton points out. 

“Naturally, shock-absorbing titanium smooths out the road.

“The one-piece carbon fork and wider carbon handlebars make it stiffer and even more responsive.”

The bike is available in two specifications, each with the option of a low and mid-rise handlebar fit: 

  • T Line One (£3,750): Singlespeed – this one is the lightest Brompton has ever made.
  • T Line Urban (£3,950): Featuring a compact 4-speed gearing system optimised for city riding.

The new Brompton T Line is exclusively available via a ballot system on Brompton.com, and through selected Brompton Junction stores including the one in London.