10 incredibly ambitious engineering students from ETH Zurich have come together to deliver an electric motorcycle that if you spotted on the street would assume was a future MV Agusta or Ducati. Having learned the basics of engineering, the group proceeded to start work on the electric bike in their fifth semester and as things stand today, they are hoping that they can somehow get their engineering college project into limited production.
We caught up with Martin Tanner, the team leader to speak about the creation and where the project is heading:
Tell us about the inception of Ethec – what was the inspiration?
Martin Tanner: With ethec, we wanted to create a change in today’s urban and suburban mobility. Today’s electric motorcycles suffer from their short range. By recovering the braking power with the help of recuperation, we wanted to cover longer distances with a smaller battery. User-experience and performance were always in the foreground, because everyone should want to ride our ethec city. Hence our slogan: “a sustainable and efficient solution for everyday mobility”
Why did you choose an electric motorcycle instead of an electric scooter which is more suited for mobility?
Martin Tanner: As stated above, we not only wanted to address the urban but also the suburban mobility, and hence we chose to build an electric motorcycle which can travel further distances and drive on faster roads than a normal electric scooter.
Can you talk to us about your team?
Martin Tanner: Our team consists of 10 engineering students from ETH Zurich; 7 Mechanical and 3 Electrical Engineers. We are bachelor-students that were in our 5th semester when the project started. We were supported by 6 master students as well as several freelancers from the industry. The project was organized by Prof. Dr. Wegener, who’s responsible for the lead of the institute for material machines and manufacturing.
Take us through the start of the build – how did you define the parameters of the electric motorcycle?
Martin Tanner: At the start of the build, our entire focus was on efficiency and sustainability. We consistently optimised and aligned each component for our recuperation. Normally, wheel hub motors are installed in the rear wheel of e-bikes. However, 75 percent of the braking energy is lost via the front wheel. This is why we decided to use wheel hub motors in the front wheel for the first time worldwide. In this way we wanted to recover significantly more energy and gain even more safety. That is were the beginning of our build started off.
Talk to us about the construction and features of the electric motorcycle
Martin Tanner: I will separate this part into the different modules of our project, to give you as many information as possible.
Electronics & Motors: Efficiency, weight and performance were the main priorities of our motorcycle. We tried to achieve better driving dynamics and unprecedented ranges through recuperation by means of a new concept with two wheel hub motors. To achieve this, we developed both our motors and inverters ourselves.
Battery: Our battery team was responsible for the range and supply of all vehicle electronics. They were developing a fast-charging, high-performance battery with a long service life. By means of passive oil cooling, we ensured that the battery cells are kept within the optimum temperature window even when riding on the motorway in summer. In contrast to the predecessor project ethec alpha, we quadrupled the voltage so that quick charging and lighter engines can be used.
Mechanics: A good motorbike experience includes riding comfort, ergonomics and, last but not least, design. Our mechanics team ensured a smooth and safe ride with a stable frame construction and a well adjusted chassis. To do this, we analysed the forces acting during the ride and design our components for this. In close cooperation with a team of designers, we adjusted the geometry of the motorbike for good ergonomics and an attractive appearance.
Software & Control: Our control team took care of everything that happens in the background. In order to have all processes firmly under control, we relied on real-time systems in ethec city. This technology allowed us to ensure the highest level of safety for the driver and his environment by constantly monitoring the vehicle. In addition, the driving dynamics and driving behaviour were optimised to the highest degree with the help of selected sensors in interaction with our software and control system, so that we can guarantee absolute driving pleasure.
Design: We wanted to pursue a concrete design strategy, we wanted the technical innovations to be reflected in their own aesthetics and at the same time quote the predecessor project Ethec alpha. Hence, a student project was launched at the University of Applied Sciences Northwestern Switzerland (FHNW), in which a design spectrum was to presented and then a direction for the project was fixed by a joint decision.
Under the direction of Lutz Gebhardt and the supervision of Johannes Hammers, students of industrial design worked in three teams to pursue different concepts and transformed their visions into scale models. At this stage the seating position, and also the creative character formation, played a decisive role. These main characteristics are responsible for whether a motorcycle is perceived as sporty or comfortable, agile or compatible, classic or futuristic.
The project was then handed over to our design team with the status of the models, which led to its implementation without losing track of the basic concept.
What are the specifications of the Ethec electric motorcycle?
Martin Tanner: Our specifications are:
- Lithium-ion technology
- 315 km range
- 15 kWh capacity
- Optimised service life through integration of passive oil cooling
- Continuous monitoring of cell temperature and cell voltage
Electronics & Motors:
- Wheel hub motors
- 2 x 16.7 kW continuous power
- Up to 70 kW peak power
- High voltage interlock for safety
- Variable recuperation
Mechanics & Design:
- Tubular frame for a low weight
- Two-sided swing arm rear as a proven design
- Complete interface via one display
Now that you have a prototype, do you have further plans?
Martin Tanner: After finishing our motorcycle-prototype, we want to do as many tests to collect as many data as possible about the performance of our bike. We do this to be able to further determine what works and what should undergo some change. The bigger picture is to initiate a follow-up project and hopefully someday be able to go into production, either as a spin-off or together with a partner company.
Is your team working on other electric vehicle projects?
Martin Tanner: Right now, six of our ten members are coaches and supporters of a follow-up project named e-sling, whose goal is to electrify a four-seater sports aircraft. Please make sure to check out their website at www.e-sling.com!
You can track the progress of the electric motorcycle by visiting ethec.ethz.ch/en/ethec_city