Innovating on fifty years of expertise.
Discover the research and development behind the all-new G Line.
Every Brompton bike is expertly engineered, handbuilt and quality-assured in our London Factory. We have 50 years of expertise in building bikes that stand up to daily use in the city. When it came to G Line, we harnessed all this and more - taking durability and testing to a whole new level.
Developing an in-house test laboratory allowed us to go beyond the limits of standard ISO industry criteria. Our purpose-built test chambers prepared the bike for all types of journeys in all conditions— from frame strength to gear and braking reliability to electric systems, we took G Line to the extremes.
Test rigs provide exceptional conditions and data that allow us to prepare for the extraordinary, but they have their limits. To make a bike truly capable, you must understand how people interact with it in real life.
Our dedicated Brompton Attributes Team (BAT) riders are experts in assessing ride characteristics and changes in the design. They took G Line everywhere. From soaking wet journeys across London to dry, sandy climbs in Spain to trips by boat, train and cycle lane across northern Europe. We wanted to understand not only how G Line rides but how it folds and fits into daily life. By combining the data from the rigs with real-life observations and experiences, we meaningfully evolved and advanced the design.
Electric bikes can play a significant part in reducing congestion in our cities. As infrastructure improves, they become an increasingly viable option for everyone. We believe a super reliable and safe e-bike that folds, stores and enjoys weekends outdoors will play an important role in the future of urban mobility. Our in-house engineering team (mechanical, electrical, software, systems and simulation) designed the Electric G Line as one. This holistic approach means we created a bike prepared for today and tomorrow.
By custom-designing the electronic system in-house, we made the hardware and software Brompton-specific. Not only does this mean we can give G Line the best ride feel and features now but also in the future. The continuous innovations shared with owners via the app are developed for Brompton by Brompton – enhancing the ride experience on this bike.
We rigorously tested the all-new rear wheel motor to the equivalent distance of the moon and back (over 1,038,640 km) and we did it in a wide variety of conditions. The temperatures ranged from from -20 to 50 degrees Celsius, the altitudes climbed up to 2000 metres all while the motor was aggressively sprayed with water, dirt and air.
This e-bike confidently goes where you go.
The next-generation Brompton battery has more capacity and power without compromising on compactness. It detaches from the front of the bike with one quick click for enhanced portability and easy charging. The redesigned mechanical fitting provides an extra level of battery security for riding on different types of terrain.
Designed with the same systems engineering approach found in the automotive and aerospace industries, the Electric G Line system sets the benchmark for quality and safety. Our bikes are independently certified and accredited – the system is UL2849 and EN 15194 compliant, and the batteries UL271. We set our safety standards high and believe everyone else should, too. Brompton actively supports greater regulation through the Battery Breakdown Safety Bill.
Like the original Brompton bike, every G Line is handbuilt in our London Factory. From steel brazing to paint plant to final assembly, we've applied 50 years of knowledge and expertise to ensure every bike receives the same level of care, detail and quality that brought us here today.
