The Brompton G Line with Roller Frame (8-Speed) introduces a brand-new era for the iconic folding brand, scaling up the classic Brompton fold around 20-inch wheels and all-terrain capabilities. Designed to deliver the geometry and ride quality of a full-sized bicycle across gravel paths, cobblestones, and urban commutes, the G Line incorporates a hand-brazed steel frame, an aluminium fork with accessory mounts, and Tektro hydraulic disc brakes for all-weather stopping power. Equipped with the rear Roller Frame, the bike folds down into a locked 72 x 67 x 41 cm footprint that rolls effortlessly through train stations and airport terminals.
Power transfer and gear selection are driven by a low-maintenance Shimano Alfine 8-speed internal gear hub providing a 307% range, keeping the chainline clean and protected from road debris. Rolling on high-volume, tubeless-ready Schwalbe G-One Allround 20x2.25" tires, the G Line comes in three distinct frame reach options (Small, Medium, Large) to ensure an accurate fit for riders of varying heights. Tipping the scales from 14.8 kg (32.6 lbs) with the rear rack installed, this build combines rugged multi-surface versatility with compact transit utility.
Specifications Breakdown
Frameset & Ergonomics
Main Frame & Rear Triangle: Hand-Brazed Custom Steel Tubing with Self-Aligning Hinge Clamps.
Fork: Aluminium Fork with Mid-Blade Cargo Mounts and Triple Bottle Bosses.
Sizing Options: Small (152–168 cm), Medium (168–183 cm), or Large (183–198 cm) with tuned stem angles and seatposts.
Folded Dimensions: 28.3" D x 26.2" H x 16.0" W (72 cm D x 67 cm H x 41 cm W).
Cockpit: Wide Alloy Riser Handlebars with Ergonomic Lock-On Grips.
Pedals: Quick-Release Left-Hand Wide Platform Pedal, Fixed Right-Hand Platform Pedal.
Seatpost & Saddle: Black Anodized Seatpost (Standard/Extended/Telescopic) with Superlight Saddle.
Drivetrain & Brakes
Drivetrain System: Shimano Alfine 8-Speed Internal Gear Hub (307% Gear Range).
Shifter: Microshift 8-Speed Thumb Trigger Shifter.
Brakes: Tektro Hydraulic Disc Brakes (140mm Rotors Front & Rear).
Crankset: 6061 Forged Aluminium Crank Arms with 54T Chainring and Integrated Chainguard.
Wheels & Accessories
Rims: 20" (ETRTO 406) Alloy Double-Wall Disc Rims.
Tires: Schwalbe G-One Allround, 20 x 2.25" (54-406), Tanwall, Tubeless-Ready.
Roller Rack: Rear Steel Roller Frame with Integrated Oversized Easy-Roll Wheels.
Integrated Accessories: Full-Coverage All-Terrain Mudguards, G Line Large-Diameter Front Carrier Block Adaptor, Frame Pump Brackets.
Approx. Weight: From 14.8 kg / 32.6 lbs (Max Rider/System Weight: 110 kg).
Key Highlights
Full-Size Bike Ride Quality on 20" Wheels: Larger 20-inch wheels paired with a stretched wheelbase and wide riser bars deliver confident stability over gravel paths, potholes, and forest tracks.
Shimano Alfine 8-Speed Hub & Hydraulic Brakes: Low-maintenance internal gear hub lets you change gears at a standstill, while hydraulic disc brakes deliver light lever pull and weather-proof stopping power.
Advance Roller Frame Luggage Utility: The factory rear rack provides stable cargo platform mounting while allowing you to push or pull the folded bike smoothly across flat surfaces.
Tubeless-Ready Off-Road Rubber: Wide 2.25" Schwalbe G-One Allround tires provide cushion and traction across dirt and wet asphalt, with tubeless-ready rims for lower pressure off-road setups.
Tailored S/M/L Geometry: Rather than a single frame height, the G Line offers three distinct frame sizes tuned for rider height to optimize cockpit reach and handling.