Independent editorial. Not affiliated with Brompton Bicycle Ltd.
The Brompton G-Line is Brompton’s all-road folding bike. It keeps the brand’s defining trick — folding small enough to carry indoors or onto a train — but adds larger wheels, wider tyres and a tougher build so it can handle gravel paths, broken tarmac and light trails that would punish a classic Brompton.
Short version: if you love the Brompton fold but ride rougher stuff than smooth city streets, and you’ll take the extra weight and bulk that buys you, the G-Line is your bike. I run one with a C-Line parked next to it, so most of what follows comes from living with both, not from a spec sheet.
Who the G-Line is for
- Commuters whose route includes towpaths, parks or rough roads.
- Travellers who want one bike that folds for trains and handles unpaved detours.
- Existing Brompton owners who find the 16-inch wheels harsh off smooth tarmac.
It’s not the bike if your priority is the smallest, lightest fold — that’s still the classic C-Line’s job, and I’ll tell you so even with both in my hallway.
G-Line vs C-Line at a glance
| Aspect | G-Line | C-Line (classic) |
|---|---|---|
| Wheel size | Larger (20”) | Compact (16”) |
| Tyres | Wider, all-road | Narrower, urban |
| Terrain | Mixed / light off-road | Smooth urban |
| Folded size | Larger | Smallest |
| Weight | Heavier | Lighter |
I’m keeping exact weights, gearing and prices out of here until I’ve checked them against Brompton myself — I won’t print a number I can’t stand behind. The specifications page has the structured table (same rule there).
Want to feel the difference? The gear & speed comparator races any two Bromptons at the same cadence — wheel size, gearing and tyre width and all.
Not sure which model is yours, or whether it will fit your life? Try which Brompton is right for you and the fold-fit visualizer.
What to check before buying
- Storage and carry. The folded G-Line is bigger than a classic Brompton. Measure where you’ll store it and how far you’ll carry it folded.
- Your real terrain. If 90% of your riding is smooth city streets, the C-Line may suit you better and fold smaller.
- Gearing for your hills. Confirm the gear range matches your climbs.
- Accessories that fit. Not all classic Brompton luggage fits the G-Line, so check before you carry one over — I’ve sorted what actually fits in the accessories comparisons.
Next steps
- Read the G-Line guides for setup, folding and maintenance.
- Check the full specifications.
- Compare accessories that actually fit.
Spotted an error or have first-hand G-Line experience? Get in touch.