Brompton has reworked its iconic folding bike design for what the company says is its lightest model ever. Thanks to the T Line's titanium frame, a new drivetrain and carbon fiber components, the finished bike comes in some 37 percent lighter than an original all-steel Brompton.
After three years of research and development, Brompton reckons that just about every part of the design has been "finessed, pared back, upgraded." In fact, about the only thing that's trickled through from the classic Bromptons is the brake system.
"We have gone over this entire product in the minutest detail, looking for every single gram we can find to save on weight," said the company's Will Carleysmith. "What we’ve ended up with in T Line is the sense that when you leave the house you can go anywhere. All of those shared environments you experience when exploring a city, the bike is not going to be a burden, and you can do whatever you want with ease. That’s a pretty amazing feeling!"
And that total weight? The T line tips the scales at just 7.45 kg (16.4 lb), not the lightest folding bike we've covered but it is a full 2 kg lighter than Brompton's recently launched P Line bikes.
For the Grade 9 titanium frame, Brompton partnered with engineering firm C W Fletcher to form a new company – Brompton Fletcher – and build a new production facility in Sheffield. The orbital and tig-welded frames are then shipped to London where Brompton adds in the other componentry and tunes the finished bike for city riding.
The T Line bike comes in two flavors, the single-speed One model and the Urban bike with a 60-g (2.1-oz) four-speed derailleur, each featuring a brand new patent-pending drivetrain that sits inside the fold.
The folding mechanism here is also different to other bikes in the company's range, sporting new self-aligning hinges, a spring-loaded handlebar catch, and a larger an "easy grab" carbon saddle with integrated nose handle. Brompton hasn't actually revealed folded dimensions for this model, but a P Line bike folds down to 645 x 585 x 270 mm (25.3 x 23 x 10.6 in) so we expect the new model to be about the same.
Rather than use a full carbon seatpost, which the company says wouldn't be up to the task of daily folding bike use, Brompton's engineers have come up with a steel-reinforced carbon design "that can take the abrasion of the fold, 110-kg [242.5-lb] load and all-weather riding."
Elsewhere, the T Line comes with a carbon crankset, aluminum pedal set, a titanium bottom bracket, lightweight 16-inch rims wrapped in puncture-resistant Schwalbe tires with 34-g (1.2-oz) polyurethane inner tubes, a one-piece carbon fork and a 560-mm (22-in)-wide carbon handlebar.
The Brompton T Line is available as two models, each with low or mid-rise handlebar options. The One version is priced at US$4,795 while the Urban bike costs $4,995. The video below has more.
Product page: Brompton T Line
