Interview with BMW C evolution Project Manager

Interview with BMW C evolution Project Manager

Now that the BMW Motorrad has presented its near-production prototype C evolution at the 2012 Olympics in London, we bring you an interview with its project manager Dr. Christian Ebner, who reveals why this model could change the urban mobility market forever.

How long has the BMW C evolution been in development?

Development on this particular electric scooter started at the beginning of 2010, but of course we have been working on concept models in this segment for some time. We introduced the concept vehicle E-Scooter at the BMW Motorrad Innovation Day in Munich in 2011, which for us was a rideable scooter on which we could check out the technical parameters and gain the information about what it would take to bring such a machine to the street. Then, at the IAA International Motorshow in Frankfurt later that same year, we unveiled the Concept e design study, which was how we thought it should look. Then the next step was for us to realize as much from the design as possible and match it with the technological possibilities, which is where the BMW C evolution comes in.

Dr. Christian Ebner, BMW C evolution Project Manager

There must be significant costs in producing not one, but five fully ridable prototypes, but how close are these to serial production models?

Yes, there are undoubtedly large costs involved and they are still prototypes, albeit at an advanced level. All the parts are made from prototype tooling so when serial production commences, there will be changes, but no major changes. For example, the contents of the rider information display will probably change in visual terms with how the graphics will actually be displayed, but the information itself – range, speed and economy – will be the same.

So, how does the BMW C evolution actually feel to ride, compared to a ‘standard’ Maxi-Scooter?

There are two answers to this question. Firstly, we tried to keep the operation of this electric scooter the same as that of a combustion-engined scooter, so that the rider does not have to change his or her behavior and learn new riding techniques. Secondly, in terms of the actual riding dynamics, the riding experience is very close to that of a motorcycle, rather than a ‘traditional’ scooter. Just like on our C600 Sport and C650GT Maxi-Scooters, the chassis, fork and swing-arm design gives a feeling closer to being on a motorcycle than a scooter.

What about the actual ‘twist and go’ operation? How does this compare?

The key difference with the C evolution is the torque, especially at low speeds. There is a constant high level compared to a combustion engine, which has a peak point at a certain engine speed. With the way that the torque is delivered, it means that acceleration is instant and fast, all the way to the electronically-limited top speed of 120 km/h [75 mph]. I was riding one of the prototypes in Munich a couple of weeks ago and there was a rider next to me on a 750cc Suzuki. When the lights turned to green he had trouble to keep up!

With the C evolution, do you think that BMW Motorrad has answered the common concerns about the range of electrically-powered two wheelers?

Yes, I think so. We did extensive research in the field of e-mobility in order to arrive at a high-voltage battery with a high capacity of 8 kWh, that would give the performance figures comparable to a Maxi-Scooter with a combustion engine – as well as a long riding range. In our early stages of development, we did lots of testing where we equipped many scooters with data-loggers and these machines were ridden in all conditions, from Monday to Friday urban commutes, to weekend leisure trips out of town. We analyzed all this data and came up with a typical commuting cycle, from which we determined that we needed a realistic 100 kilometer [60 mile] range from the battery, according to the vehicle’s weight and rolling resistance.

Being able to draw on the resources with the BMW Group in terms of shared technology must have been a real advantage with cutting development time and costs?

Absolutely. The C evolution uses exactly the same battery modules that will be used to power the BMW i3 automobile, although there are eight in the BMW i3, whereas we only need three! The lithium-ion storage modules come from the same assembly line and have undergone the same testing procedures, so because we did not need to do this ourselves, this saved an enormous amount of time, resource and manpower. Of course, it wasn’t easy to integrate them in the C evolution, as they were made for a car, but that was the challenge of the design and development team to put them into a good-looking vehicle. This was not easy, but as you can see, the result is pretty good.

There must be many other advantages to being able to draw on the ‘in-house’ experience and expertise in the development of electrically-powered vehicles?

Yes, we also have the complete battery electronics from the automobile division, as well as the concept of the integrated plug-in charger, so there are lots of common parts. Importantly, there are also many advantages in terms of the safety aspects. Our car colleagues have done extensive research as regards the safety of electronic vehicles. There are regulations in dealing with voltages above 60 volts DC – known as ‘high-voltage’ – in an automotive environment, such as protection, isolation, warnings etc. Furthermore, a machine powered by lithium-ion cells has different requirements in terms of safety compared to one that is petrol-driven. You need to think about things such as protection against over-charging, and safety measures against frontal and side impacts. All these things can take a long time if you have to start your research and testing from scratch, but fortunately we didn’t, which is why we are able to bring the C evolution to the market soon. This vehicle is also the first powered two-wheeler that has been developed according to ISO 26262 (a well-known standard for functional safety and reliability established by the automotive sector) which is unique in this segment.

What about the energy recuperation technology, how does that work?

Energy recuperation to extend battery life isn’t a new concept, but what is new for this electric scooter is the actual activation of the technology. With other electric scooters currently on the market, you have to actively engage this, but our intention was that the rider should not have to think about this, and that the machine itself does all the work automatically. For example, one of the energy recuperation points is the throttle grip. When you release this grip on the BMW C evolution, the e-motor actually ‘simulates’ engine torque, which feels to the rider like conventional engine braking, so as soon as you release the throttle you have a degree of deceleration that you wouldn’t normally have on an electric vehicle, but which also has the advantage of regaining energy for the battery.

The other area where regeneration is also carried out is during braking. When brake pressure is sensed on the front and rear brake lines by the levers being activated, the power electronics detect this and the e-motor builds up drag torque, which not only aids the braking effect, but also recuperates energy.

Does this feel any different when riding and how much energy can actually be saved?

For the rider, this is all very transparent – he or she won’t feel any difference to that of a conventional combustion-engine two-wheeler, but by regaining energy during coasting or braking, our simulations have shown that the range of the BMW C evolution can be extended by approximately 15 percent. Furthermore, we make this visible to the rider on the information display in the cockpit, so that a graph illuminates on the right side when energy is being used, for example, when accelerating hard. Then, a graph on the left side of the display will illuminate when energy is fed back to the battery. We believe that this will make riders think more sustainably and perhaps even change their riding style!

And finally, do you think that the BMW C evolution could be the most important new addition to the current model range when it launches?

Well, all new motorcycles are important to BMW Motorrad but there’s no denying that the C evolution is an exciting new chapter in the history of the brand. It’s a special kind of electric scooter that follows the BMW Group’s sustainability strategy and we hope that it will become a long-term part of the model range.

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