Brompton G Line Electric folding bike
The G Line Electric - Gravel? Line range was introduced by Brompton in autumn 2024 (with the 2025 lineup of bikes). Whatever the G stands for it's built for adventure
It has larger wheels than the traditional 16 inch Brompton size at 20 inches - but that's not the only change - almost everything is different!
The G Line electric also uses a rear wheel motor and all new (Greenway) battery (compared to the the original C Line Electric) and small light 2A charger small enough to fit in the front pocket of the included essentials bag
The G Line electric has been so popular since its launch in autumn 2024 that we have really struggled to keep up with demand!
Brompton G Line Electric specifications:
1. Frame |
Main Frame: | Steel |
Rear frame / triangle: | Steel |
Front forks: | Alloy |
Handlebar stem: | Alloy |
Folded size: 71cm wide x 68cm tall by 38cm deep (approx)
The handlebar stem has water bottle bosses so you can mount a water bottle for easy hydration while riding. (we recommend the Fidlock system so the bottle cage doesn’t interfere with the fold)
2. Colour |
When the G Line Electric (and G Line) were launched in autumn 2024 they were available in 3 colours:
- Adventure Orange
- Traildust White
- Forest Green
In autumn 2025 a new colour option was added:
- Space Black
Main frame: | Choice of colour |
Rear frame / triangle: | Colour matches main frame |
Handlebar stem: | Black |
Front forks: | Colour matches main frame |
Folded size: 71cm wide x 68cm tall by 38cm deep (approx)
The handlebar stem has water bottle bosses so you can mount a water bottle for easy hydration while riding. (we recommend the Fidlock system so the bottle cage doesn’t interfere with the fold)
3. Size |
Available in 3 sizes - small, medium and large
The G Line Electric only has one handlebar type - ride position is dictated by the stem length and seat post length
Handlebar width - 65cm
4. Gears / drivetrain |
- 4 speed Brompton derailleur gear system (11T / 13T / 15T / 18T sprockets)
- Motor built into the hub of the rear wheel powered by the battery on the front of the bike
- 50T front chainring - black (we can change to 44T to reduce gearing if you would prefer)
- Torque sensing square taper bottom bracket - this senses the power you are applying to the pedals and then delivers power to the rear wheel - the more you press the more power the motor will deliver
- Brompton advance chain (106 links) with connecting link
- Flat platform pedals (the right one is removable and stows in the back of the front fork to make the bikes folded size smaller)
5. Front luggage system |
The G Line Electric comes with the electric e-Motiq front carrier block fitted - this connects to the battery and sends power to the motor
The bikes comes complete with the Essentials bag containing the battery
Standard Brompton luggage is not compatible with the G Line electric front carrier block
6. Mudguards / Rack |
The G Line comes with black mudguards (front and rear) and an advance rack
Note: The rack doesn't have bungee cords as standard
7. Roller Wheels |
Large new G Line roller wheels help keep the bike stable when folded
Front roller wheels are 70mm
Rear roller wheels are 80mm
Top tip: Replace the 70mm wheels with 80mm ones and it will help prevent the rear rack getting scratched when folded
8. Tyres / Wheels / Brakes |
Tyres
Schwalbe G One tyres with tan wall (ETRTO size 54-406) - tubeless ready
or
Continental Contact Urban tyres - designed for commuting - these require an inner tube
Both tyres have a low rolling resistance and good puncture protection
Wheels
20 inch wheels
The wheels have black hubs, black spokes and black rims
Presta / racing type valve
Brakes
TRP Hydraulic disc brakes
Brake Rotors:
- TRP Centrelock 25 - 140mm front
- TRP 6 bolt - 160mm rear
About the TRP Centrelock 25 rotors
TRP’s slotted rotor is designed for the most demanding riders in the most demanding conditions. The aluminium spider gives superior heat dissipation and excellent stiffness. Six recessed slots create channels to allow water, mud, and other debris trapped between the pad and rotor to escape during braking. When debris gets trapped between the pad and rotor braking power is dramatically reduced, these recessed slots maintain a more consistent brake feeling in mixed conditions. Upgrade the stopping power and heat dissipation by increasing the size of your rotor giving you more surface area and leverage.
TRP - Tektro Racing Products
9. Saddle |
Brompton saddle
The saddle is connected to the seatpost using a Brompton Pentaclip for easy adjustment of saddle angle / position
The saddle has a light mounting point on the underside allow additional lights (e.g. the VIZ 150 light) to be attached to the underneath of the saddle
10. Seat height |
Size small uses a standard seatpost - black colour
Size medium uses an extended seatpost - black colour
Size large uses a telescopic seatpost - black colour (which means it actually folds down smaller than a medium size)
11. Suspension |
Along with the new G Line comes a new advance suspension block
12. Lighting / reflectors |
- Lezyne E115 front light
- Busch and Muller rear light
The lights are powered by the battery which powers the motor
Three lighting modes are available:
- Off
- On
- Auto sensing - turns light on only when dark
| Colour | Space Black, Forest Green, Adventure Orange, Traildust White |
| Size | small, medium, large |
| Tyre choice | Schwalbe G One, Continental Contact Urban |