If you were to ask a Brompton owner which three characteristics most distinguish their bike, it’s likely they would highlight its incredibly practicality; the almost beautiful innovation throughout its design; and its unsurpassable ride experience. So when it came to creating an electric version of this folding icon, Brompton knew exactly what areas it needed to perfect. Brompton CEO Will Butler-Adams talks us through the Brompton Electric and why it fits perfectly into the Brompton family.
Brompton has never rushed any of its products, and it definitely didn’t see a need to change that approach for the Brompton Electric. The company spent six and a half years developing its electric bike, time which allowed Brompton to refine, evolve, improve and delve deeper into the detail of the design. It also allowed the company to develop technology that had never been used before to come up with something that was practical, useful, fun and delightfully Brompton through and through.
As with traditional pedal-only Bromptons, the Brompton Electric has been engineered to be small, portable, high performance and robust. It’s also been designed to overcome issues of the security and e-bike storage in cities. Compared to most alternatives, the Brompton Electric is lighter and smaller, yet has a surprisingly large battery capacity, good range and suitably powerful motor. And it still looks just like a traditional Brompton bike, with the same folding mechanism and all the same functional benefits.
Technology and development
Those family similarities belie the effort and time that has gone into a truly Brompton electric bike. This is definitely not a case of dropping an e-bike drive system into an existing Brompton design. The Brompton Electric has a new fork that has been created to cope with the heightened forces generated by the electric motor; there is a new mainframe to accommodate the wiring; and increased-strength parts have been used in other areas of the bike to meet stringent European electric bike standards.
When it came to creating the bike’s drive train, Brompton also spent a significant amount of time finding the right partners to work with. Williams Advanced Engineering, part of the Williams F1 group, played a significant role in developing the powerful yet narrow front wheel motor. A lot of effort went into software and algorithm development to make the bike a joy to ride. Then the final product was subjected to stringent real-world and lab-based testing to eradicate any potential problems.
How it works
Those might be some of the lengths that Brompton has gone to during the development of its electric model, but how does the Brompton Electric actually work? As you’d expect, it’s not quite like a ‘normal’ e-bike. In the Brompton Electric’s case, the 250W motor is built into the front wheel hub, while its easily removable 300Wh lithium ion battery – which gives a riding range of 20 to 45 miles – is housed in the luggage that sits at the front of the bike. This approach allows for easy access to the user interface and USB charging port.
An advanced control system then regulates all these components. A sensor in the bottom bracket measures the rider’s cadence and torque, while a sensor within the hub motor measures the speed of the bike. A custom set of algorithms uses this data to send an appropriate torque request to the motor. This multiplies your pedalling effort, helping to make accelerations, climbing hills and riding into headwinds almost effortless. The maximum output from the motor is restricted so that it will not give assistance beyond 15.5mph but the rider can choose the level of power it provides to suit their riding style.
Owning experience – better than ever!
As well as all the practical benefits that a traditional pedal-only Brompton provides, one of the main aspects that marks it out against other folding bike designs is its fantastic ride experience. Despite its small wheels and unconventional frame shape, the traditional Brompton is reactive and just a joy to ride. The Brompton Electric is no different, with the advantage of the electrical assistance meaning that factors beyond Brompton’s control – hills, headwinds and fatigue – can be faced with confidence.
Another of the pedal-only Brompton’s benefits has been its incredibly low overall weight and small folded dimensions. The Brompton Electric’s slim, light motor means the folded pack size has remained exactly the same as the standard Brompton. Meanwhile, having a battery that is integrated into the luggage means the carry-weight of the packed bike is reduced by nearly 3kg. The Brompton Electric owner can lift off their front bag with the battery, sling it over their shoulder, and have cut the weight of the folded Brompton to a manageable 13.5kg.
Life with a Brompton Electric is not just fun but easy. A Brompton Electric owner can charge the battery by simply removing the bag from the bike and plugging it into a normal wall socket. The standard charger, which is included, charges the battery up to 80% in 3-3.5 hours, and to 100% in 4-5 hours. (An optional fast 4A charger can charge the battery up to 80% in 1.5-2 hours, and to 100% in 2.5-3 hours.)
So try a Brompton Electric at one of our Brompton superstores today and see how the world’s best folding bike just became a little better.