Adventure Unfolded: A Look at the Brompton G Line

“Can I take a Brompton off-road?” It’s a question dealers have heard for years. Until now, the answer was cautious: maybe, depending on how daring you are. With the Brompton G Line, the answer is simple: yes—you absolutely can.

Built from the ground up for gravel and off-road use, the G Line thrives when the pavement ends.

Built for Adventure

At first glance, the G Line looks like a classic Brompton. But every detail has been re-engineered for rugged terrain. The all-new steel frame is designed to handle the demands of gravel riding, while still folding into a compact package when the ride is done.

The most striking change? The 20-inch wheels wrapped in 2.1” Schwalbe G-One Allround gravel tires. These larger wheels provide stability, grip, and ground clearance for uneven trails—rolling smoothly over loose gravel and chunky surfaces.

The stem is angled to give more reach, allowing riders room to shift their weight easily off-road, and for the first time ever, a Brompton comes in sizes Small, Medium, and Large for a more dialed-in fit. Even the hinge clamps have been redesigned to stay rock-solid against the vibrations of gravel riding.

Despite these changes, it’s still a Brompton at heart: it folds quickly, rolls easily on its heavy-duty rack with oversized rollers, and tucks neatly under a desk or into a vehicle.

Key Features

The G Line packs a host of upgrades, each chosen with off-road riding in mind:

20” wheels for stability and rollover ability
2.1” Schwalbe G-One Allround tires: wide, grippy, and tubeless-ready
TRP hydraulic disc brakes: powerful stopping in all conditions
Shimano Alfine 8-speed internal gear hub: sealed, low-maintenance drivetrain
Compact chain tensioner with a strong spring: stays out of the way and reduces chain slap on bumpy trails
Wide handlebars with ergonomic grips: comfort and control off-road
Microshift two-lever shifter: smooth, reliable shifting
Bottle cage mounts (yes, on a Brompton!)
Fenders to keep grit off you and your bike
Heavy-duty rear rack with large rollers for carrying gear and rolling the folded bike
Front carrier block for Brompton luggage

On the Road and Beyond

On pavement, the G Line feels stable and smooth, more like a full-size bike than a folder. It’s heavier than a 16-inch Brompton and trades a bit of agility for cruising comfort.

But the G Line really shines off-road. On gravel rail trails, rolling singletrack, or gravel roads, it delivers effortless progress. The low gearing makes climbing easy, while the stability inspires confidence on loose surfaces. The tires grip and hold, whether you’re cornering or braking.

This isn’t a mountain bike—you won’t want to take on big drops, jumps, or rock gardens—but for gravel adventures, rail trails, and dirt paths, the G Line is perfectly at home. It rolls and rolls, covering long distances with ease, and invites you to explore further.