How Brompton is steering the future of electric bicycles

Posted on 28 May 2020 by The Manufacturer

In this exclusive factory tour and interview, The Manufacturer meets up with Brompton’s chief operating officer Paul Williams to discuss the new factory, Brompton’s training programme, two recent automation installations, the company’s electrification development with Williams Advanced Engineering, and the secret to Brompton’s unrivalled success in the personal transport industry.

There are many manufacturers located on the Greenford Industrial Estate in West London, but one among them is renowned for its truly unique – and some might say ‘quirky’ technology – which led to it becoming a household name and design recognised the world over.

Brompton Bicycle Ltd moved to the Greenford estate from Brentford three years ago to take advantage of a much larger factory and manufacturing capability, as well as to house several new innovations and an ever-growing, locally sourced workforce.

Brompton - award-winning innovative folding-frame design

The brand has become synonymous with efficiency and responsible attitudes towards the environment, as well as for its seemingly conventional design that betrays a much more innovative technology in the personal transport marketplace.

Founded in 1976 by inventor Andrew Richie, Brompton’s road to success wasn’t a smooth one – despite winning many export, design and sales accolades.

Brompton’s first iterations, prior to the folding-frame design it eventually become famous for, were rejected at the time by much larger bicycle manufacturers like Raleigh, who just didn’t get it.

Unable to strike a partnership that would enable Brompton to step its production up a gear, the company resolved to go it alone, investing internally in its technologies and staff, resulting in a slower rise to the summit of British design and bicycle manufacturing.

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More than four decades later, Brompton hit sales of £42.5m in 2019, an 18% year-on-year increase, and with the significant target of 60,000 units sold now in sight, the company is looking once again to the future of mobility and to its role in driving the pace of cycling evolution.

Slick, efficient and charming

Our tour of Brompton’s Greenford factory begins in the company’s mini museum, an ‘antechamber’ of now redundant versions of the Brompton bicycle mounted on the walls with historical descriptions underneath, to rows of ultra-modern, lightweight iterations in a variety of colours and metals on small podiums, showcasing the evolution of the Brompton over decades.

Paul Williams, Chief Operating Officer, Brompton
Paul Williams, Chief Operating Officer, Brompton

Although more advanced and therefore more costly for the customer, the overall design is still very much the same: that distinctive low, angular frame and high seat and handlebars that can be folded down to an area the size of a small suitcase and erected again in a matter of seconds.

Leading away from Brompton’s history section, COO Paul Williams opens the door to the company of the present, and indeed the future.

It all hinges on the hinge

The jewel in Brompton’s manufacturing crown is undoubtedly its brazing capabilities. The largest production cell on its factory floor comprises tens of individual workstations manned by as many people.

Brompton prides itself on its ability to fuse different types of metal together individually and in a style that while neat and effective, does not hide the unique handiwork of each technician responsible.

Indeed, Brompton has installed a ‘brazing board’ adjacent to the production cell, showcasing dozens of Polaroids of brazing work undertaken by its specialists. Each is unique to the worker for its tight, or conversely less crowded layering, at the bicycle’s joints – while remaining equally strong and meeting all design and production specifications.

“For me it’s really important our employees understand the cause and effect of what they do,” said Williams. “Brazing requires the highest commitment and skills level, and there aren’t many people doing brazing of this nature in the UK.”

“We consider out-house and in-house applicants for these roles, but at the moment we are finding more success with people hired internally, who see the brazing every day, who know what we’re about here, and who have a desire to get the torch in their hands.”

The unique handiwork of each technician is an artisanal feature of Brompton’s production process

The unique handiwork of each technician is an artisanal feature of Brompton’s production process

“We run a fairly intensive in-house training programme and build up over an 18-month period before trainees are given a real project, and we’ve found being diligent in that pursuit highly effective,” he added.

Not wishing to rest on its laurels, the company is experimenting with three brazing machines designed and calibrated in-house by its own engineers to produce the unique ‘Brompton hinge’.

“These are our ‘autobraze’ machines that join the cast hinge to the thin walled tubes,” explained Williams. “They use pyrometers to monitor heating and cooling profiles as the brass is melted between the hinge and tube components. All three are fully-operational production ‘war horses’.”

This hinge is the critical component that defines the Brompton bike, enabling it to fold perfectly away and be stored, without compromising the bike’s performance, durability or safety.

It is this very hinge, seemingly simple in design but resilient and internally complex owing to miniscule notches allowing for precision and flexibility, that sets Brompton apart from copycat designs which cannot fold down in the same compact way, Williams said.

One Brompton-built hinge brazing machine is entirely manually operated, while another is part-operated by a technician and partly by automation, and a third is almost entirely robot-operated.

Brompton - Automation has delivered 20%+ volume gain for two years in a row

Automation has delivered a more than 20% volume gain for two years in a row

Williams told The Manufacturer that while the company is always considering scope for automation, development in those areas does not need to come at the expense of its employees.

Many will be retrained in how to operate such machinery, and in its current triple-machine set up Brompton is able to experiment with three very different hinge production processes, each as valid as the next.

Williams said Brompton hinges brazed individually are also inscribed with the technician’s initials in ‘shadow’ parts of the component, allowing the company to monitor the quality and traceability of each hinge, while cultivating a simple system of pride and personal responsibility among its workforce.

Complementary colours

Two recent automation additions to Brompton’s Greenford site are in its painting department. Installed just before Christmas 2019, the company invested some £250,000 in two separate companion technologies in order to automate this area of production.

Brompton now has a floor-to-ceiling ‘paint picker’ which stands some 31 feet high and more than 14 feet across, silently selecting a range of colours to paint the bicycles and operated by a single technician who inputs the required colours via computer.

Once programmed, those selected colours are automatically fed into a separate, giant unit which carries the Brompton bicycles through on a conveyer-like hooking system and are sprayed from multiple angles according to requirement.

Brompton - Sensors identify the various heights of multiple parts on hangers as they go through powder coating spray

Sensors identify the various heights of multiple parts on hangers as they go through powder coating spray

Again, a single operator is charged with overseeing the entire robot from a control board, while manually using hand-held paint spraying apparatuses to get into all the ‘shadow’, or hard to reach corners of the frame the robot misses.

Since the end of 2017, the paint plant has used sensors to identify the various heights of multiple parts on hangers as they go through powder coating spray – bringing a degree of automation to the process and enabling a throughput of 25,000-30,000 parts a month through this system.

This represents a 20% volume gain, nearer 30% in the past financial year, and contributed to addressing one of the most ‘clunky’ bottlenecks in the business.

“Other areas of automation we’re considering are in those which don’t bring value add to the company – for instance the movement, locating, and loading of stock. So, we’re looking at AGVs (automated guided vehicles), nothing bleeding-edge, but logistics are really one of the best places to start.”

“And we are really on a recruitment and growth drive so if I can redeploy people currently doing those jobs in areas where they will create more value add then I will. After that, we would just refine those processes over time to give rise to a more agile operation overall,” Williams added.


A major development in Brompton’s portfolio is the emergence of its electric bicycle range.

Still in the early stages, though already exporting some 6,000 units globally a year, the electric bike marks a step-change in Brompton’s attitude towards the future of the personal transport marketplace and the role it wants to play in leading that evolution.

Williams Advanced Engineering C-X75

Williams Advanced Engineering is a technology and engineering business, providing world class technical innovation, engineering, testing and manufacturing services

Brompton has teamed up with Oxford-based cross-industry engineering leaders Williams Advanced Engineering in the development of this technology, to take Brompton’s technology from design phase through to implementation.

WAE is perhaps best known for delivering discrete project support, right through to ground-up vehicle development programmes and associated support packages in automotive, especially in Formula One motorsport.

One of the key challenges Brompton successfully overcame when developing its electric bicycle, was how best to install a discreet motor inside the bike frame without compromising on the unique hinge design, efficient folding characteristic, or the size and weight of the product.

“We could have gone back to the beginning with a blank sheet of paper and started again, but we recognised the USP Andrew Richie’s product had and there’s a huge responsibility to build on that foundation,” said Williams.

“We went to WAE as our development partner because we had a challenging set of constraints to overcome and incorporate into an existing product.”

“We needed to produce the smallest width electric motor in the most compact, lightest-weight form, still in-keeping with the uniqueness of our product and now with a removeable battery and a separate, compact charging package – while retaining a Brompton bike the rider can transport anywhere.”

“We ended up with a system that has a front wheel hub-drive motor delivering the power we needed, a battery that sits in our bagging system, and pushed tolerances right down to the nth degree in terms of the stack within the motor.”

“The flipside has set us some real operational challenges, there is no room for waving outside those really tight tolerances for everything we do because everything is stacked so tightly.”

“From that we’ve built a system we think gives real benefit to the customer. And we’ve essentially taken the pain on the operational side, by having a slower Takt-time, a more controlled training programme, as well as retaining in-house capabilities our suppliers thought were not possible.”

“We’ve really had to push ourselves within manufacturing capabilities to meet the requirements of our in-house goals and those we were pushed to by Williams and what they thought was possible.”

“We could be producing a lot more electric bikes due to the demand, we could flood the market – but we’ve held that spacious Takt time to make sure we learn and develop that product and integrity every time,” said Williams.

Brompton’s electric bicycle production cell is unique among the others in the factory, because in addition to being sparsely populated with relatively few technicians, it also moves at a much slower pace as the work requires near surgical precision.

challenge is having enough engineers out there at the level we need.

One of the challenges facing Brompton is having enough engineers at the level it needs. 

Williams told The Manufacturer that of the technicians currently working in the electric bicycle production cell, almost all were seasoned Brompton employees with the highest level of technical skills, many with more than two decades of service at the company.

All are also receiving additional, ongoing training in electric bike manufacture, he said.

The challenge of recruitment

“Recruitment in manufacturing is a constant challenge here at Brompton. We are in a particularly challenging place in West London, in that not a huge amount of manufacturing happens here,” Williams explained.

“If I go to the automotive sector in the Midlands and try to recruit from there, I am competing on an entirely different cost basis from what it costs a person to live in west London – for instance, with like-for-like salaries, we simply won’t stack up because it is much higher here.”

“Our challenge is having enough engineers out there at the level we need. Currently, our workforce is comprised of about 37 nationalities, but many are locally sourced. Our job is making this an appealing place to work while recognising we are in a higher than average cost of living part of the UK.

“We do what can in terms of school tours, volunteering days, events where we can get engineering and manufacturing into the minds of young people and especially among females. Our customer base is 50% female and we’d like that to be represented in our design, our manufacturing and our management.”

With a workforce of 37 nationalities, Brompton’s focus is on making the company an appealing place to work.

With a workforce of 37 nationalities, Brompton’s focus is on making the company an appealing place to work

“Other challenges we face are a fast-moving world, having to manage things on a global scale, sales activities in our global offices, supply chains in Eastern Europe, right down to those 1,200 components hitting the production line right when you need them.”

“But that’s common to all manufacturers and we are just pleased to be a part of that and creating a product that, when it reaches the customer, essentially makes them happier and healthier, and enables them to live in the city in a different way. It’s a privilege to contribute to a greater good,” added Williams.

Agility, Brexit and Coronavirus

“Out of nowhere came this virus and businesses are doing what they can to mitigate. But at the end of the day you must have the flexibility in your operational capability to flex and pivot as required,” said Williams.

“That is potentially one reason why we haven’t gone in for wholesale automation, because that reduces flexibility on the level of technical capability, and by being a predominantly human-based operation we can redeploy, putting people where they need to be to react to those changing situations.

“Brexit is another factor that informs this way of working and we will act accordingly as things become clearer for business,” he concluded.

Reporting by Rory Butler

*All images courtesy of Brompton