A group of Twente students, from the University of Twente and Saxion University of Applied Sciences, are preparing for the first race with the Electric Superbike Twente electric racing motorbike they developed. The first test metres have already been made.
The first small-scale tests have gone well, according to the students. The machine responds well to throttle and brake controls. Last week, the bike was tested more extensively at a track in Emmen. That too went as expected.
Team Electric Superbike Twente is a team of 15 students from the University of Twente and Saxion University of Applied Sciences, who designed and built an electric motorbike from scratch in less than a year. In doing so, they had the help of several companies. The team was founded by Tim Veldhuis and Lars Haarmeijer, both of whom already had racing experience. "I had the honour of being the first to ride our bike," team manager Veldhuis, an Industrial Design Engineering student at the University of Twente, told De Ingenieur. "It rode very smoothly, which was nice to experience. The machine listens very well to what you do with your hands. It responds instantly and drives snappy."
It is therefore a spirited motro: it has 200 hp and accelerates from standstill to 100 km/h within 3 s. Unlike a petrol engine, Electric Superbike Twente's electric motor has maximum torque available immediately from standstill. And it weighs only 220 kg.
Real test
Last week saw the first serious tests. The team's driver, Thijs Peters, rode the bike on a circuit in Emmen, collecting all kinds of data along the way, such as temperatures of the batteries and electronics. But the degree of suspension front and rear and tyre pressure, which is a measure of tyre temperature, were also measured. "We want to know if all these values remain neatly within agreed limits. Especially for optimal operation of the battery packs, it is important to keep their temperature below 60 °C," says Veldhuis. The batteries are air-cooled, the electric motor and inverter water-cooled.
Difficult job
The students designed and built the motorbike from scratch, investigating pretty much all the different options in the beginning. "That was a huge amount of work," team member Bram Norp, designer of the fairing (the outside of the motorbike) tells De Ingenieur. "Take the frame, for example, which on a regular bike is often a latticework construction. But we ended up abandoning that (see photo below). In fact, you can make the electric motor part of the supporting structure. That gave us more freedom of design compared to a petrol engine."
There are more differences from a 'normal' motorbike. The Electric Superbike has a lot more electronics on board. Central to this is the Electrical Control Unit (ECU), a kind of computer that ties everything together. 'This is the brain of the motorbike,' says Norp. It is badly needed, because each of the ten battery packs already has its own circuit board that regulates that they can function optimally in terms of temperature, current, etc. The ECU communicates with all these electronics, as well as with the inverter that converts the direct current from the batteries into alternating current for the electric motor.
Driving
Many of the team members ride motorbikes themselves. Nevertheless, an outside driver was recruited for the races, the experienced Thijs Peeters. He will have to get used to the handling of the self-built bike. Especially when accelerating, he will have to pay attention, because the electric motorbike immediately has maximum torque. If used incorrectly, this means an involuntary wheelie (the front wheel comes off the ground) or worse, ending up on the tarmac.
Furthermore, the Electric Superbike is a continuously variable automatic and so it has no clutch and no engine brake. "On a regular motorbike, you can brake on the engine, but on ours, you can only brake on the brakes. Whether we will use regenerative braking, so you recharge the batteries a bit, we still have to decide. The gain from that is smaller than with a car, because with a braking motorbike, a lot of pressure comes on the front wheel, while the electric motor engages on the rear wheel," Norp says.
The students came up with the motorbike themselves, but they did get help from several companies. At Ten Kate Racing, a professional racing team, they could always turn to for advice. AEGROUP helped the student team with their own design of the electric motor. ProDrive also contributed its knowledge, in designing the motorbike itself and the circuit boards of the engine's electronics.
The first race
After next week's measurements, the team may make minor adjustments to the bike. The first real race will then take place on 10 and 11 August, on the Donington Park circuit in England, against other electric motorbikes, with other races to follow later this year, including in Assen. The special motorbike could recently be admired up close at the Zwarte Cross, a music festival in the Achterhoek region.
Source + photo: The Engineer/Electric Superbike Twente.
