Swindon Powertrain explores electric powertrains

The Swind EB-01 is the result of an engineering-led business proactively adapting to a changing world and making the process both enjoyable and a commercial success, as Nick Fleurot reports

If you want to truly understand something, then the best route is to build it. That’s certainly the case for Swindon Powertrain. For close to fifty years the firm has been making high-performance engines and componentry. The power behind the British Touring Car Championship’s TOCA engine, as well as a manufacturer of one-off and low-volume engine parts for OEMs, is now investing heavily in electrification. But how did a firm, that was created to service F1 engines, decide to start its own electric revolution that now includes a high power-density powertrain with installation kits for classic cars and the first ever hyper e-bike, packing a substantial 15 kilowatts of power?

Understanding electric powertrains

For the team at Swindon Powertrain the project began with an objective to acquire first-hand knowledge of electric powertrains. Mindful of the wave of electrification sweeping through both ground vehicle markets and motorsport, the company set the intention to become a knowledge leader in the field, creating robust, high-performance powertrains just as it has for internal combustion (ICE) applications. The first question was how to become au fait in the technology as it started to dedicate resource to electrification?

Initial thoughts revolved around creating its own car but it was soon realised that a two-wheeler could teach them even more. The need to package, protect and keep the weight down for an e-bike that could be ridden until the rider tired (around two hours), made it a challenging project but one that technical director Sylvain Rubio relished. “It was a dream project really,” says Rubio. “We had a clean sheet of paper and around 1,000 hours of engineering time to dedicate.”

The EB-01 is the result and is reckoned to be a true tour de force for e-bikes. A range of 80 miles and a charge time of less than 90 minutes mean it is ideally suited for a rider to head out for a couple of hours of hard riding and still be able to pedal home if needed. Too powerful and too fast for the road – it will easily reach 60mph and out-gun most motorbikes off the line – the staggering performance is testament to the novel design from a team that had no two-wheeled experience before starting.

Swindon Powertrain chooses CNC over carbon

Whilst many would consider pure carbon for the frame, Rubio opted for a hybrid aluminium carbon construction. The reasons were manifold. The frame could be CNC machined without expensive tooling and thanks to Swindon Powertrain’s in-house 7-axis CNC capability, it could employ complex machined parts and produce them quickly. The frame also acts as the casing for the 1.75-kilowatt-hour lithium ion battery, eliminating unnecessary weight and enabling the team to get very close to its 40kg target. This packaging solution not only saved weight but also ensured the design could incorporate air cooling for the motor and also house the 9-speed sequential gearbox.

To better understand how to create electric powertrains, the team developed in-house the inverter, controllers and dashboard, acquiring software and hardware knowledge that has been instrumental in its subsequent ‘crate’ EV HPD product.

“It was crucial that the project be a valuable training and learning tool but as engineers we wanted it to be original and fun,” adds Rubio. “We learnt a lot about packaging that has enabled us to get the HPD powertrain to weigh less than 50kg and that includes lubricants, the brushless permanent magnet motor, transmission, open differential and a metre of cabling. With a package size of 441mm x 384mm x 228mm, HPD is also the highest power/volume unit for automotive applications on sale. The bike definitely served its purpose.”

Future applications for Swindon Powertrain

The bike has quickly acquired cult status with sales across the world. With each e-bike built to order, every element can be customised including wheels, tyres and frame colours. The novel frame design means that the core remains the same regardless of rider size, simplifying production. Tuning fit to accommodate the rider can be achieved through the seat and handlebars, with carbon options for both. To date, sales have focussed on private individuals, but the company believes the rugged nature of the original design means it would take very little additional work to create a military spec or a ‘commercial’ version for forestry workers or agricultural use.

For Swindon Powertrain, the focus of EB-01 is now on commercialising the product, with new dealers set to be added as opposed to significant design changes. “We are an engineering business and have a number of high performance, correctly engineered EV projects to look forward to,” suggests Rubio. “As electrification has become popular, there has been an explosion of solutions launched, ranging from very good quality to shockingly poor.”

Swindon Powertrain isn’t giving up on the internal combustion engine

With its reputation for producing performance engines and prototype engine components such as cranks and cams still in demand, the business remains active and acquired new projects in 2020. “We haven’t abandoned ICE powertrains and have in fact expanded our services for classic engines this year,” adds Rubio. “We will continue to supply the TOCA engine to the BTCC once more in 2021 but electrification is growing fast. Our decision to get ahead was the right one and we will continue to engineer our way to success.”