As most of you probably know, BMW is more than a car manufacturer. Motorcycles have been wearing the Bavarian roundel’s badge for decades. BMW’s motorcycle division known as BMW Motorrad, is in the final stages of developing the “C evolution,” a high-performance electric scooter.
With the C evolution, BMW Motorrad presents its first near-production prototype of a high-performance electric scooter. Starting today and until August 12, five fully roadworthy prototypes will be tested in road traffic in the city center of London. Trials will continue in other European cities afterwards. In the course of this pilot phase, the C evolution will be tested in real conditions and in various markets. This will allow BMW Motorrad to gain experience in the field of e-mobility in preparation for the launch of the future serial production model.
BMW Motorrad had two particular requirements for the development of the C evolution: performance figures comparable to those of a maxi scooter with a combustion engine; and a long range in realistic conditions of use.
With 11-kilowatts of continuous output (homologation according to ECE R85 to determine motor outputs) and 35-kw peak output, the C evolution has a powerful motor and provides a high level of riding fun. The top speed is electronically limited to 120 kph (74.5 mph).
According to BMW, the scooter supremely handles motorway riding and overtaking – even with a passenger. It is also capable of effortless hill starts on steep slopes with a pillion passenger. In terms of acceleration from 0 to 60 kph (37 mph), it comfortably holds its own against current maxi scooters a capacity of 600 cc or more.
Compared to conventional combustion engines, the electric drive of the C evolution also offers significant advantages at low speeds in particular. Thanks to elaborate power electronics settings, the alternator offers the rider an instant, spontaneous response. There are no delays in torque build-up at all as are typical in combustion engines due to the clutch engaging and disengaging.
At 8 kwh, the storage capacity ensures a range of up to 100 kilometers (62 miles). As in other areas, BMW Motorrad has been able to draw on synergy effects with BMW automobiles here. For example, the C evolution uses the same lithium-ion storage modules that are installed in the BMW i3. Here, developers paid particular attention to the quality and service life of the storage modules so as to ensure that the range is preserved even after many years of service life and in very cold weather.
One of the main technological challenges was optimum cooling of the high-voltage battery. On the one hand it was necessary to avoid excessively low temperatures due to the fact that the interior resistance of the cells is heavily increased as a result, thereby reducing power. On the other hand, the temperatures must not be too high since this would impair the life of the cells.
While in electrically powered cars a cooling agent is normally used to cool the battery, air cooling is used in the C evolution in order to save space and weight. The heat of the high-voltage battery is dissipated by means of an aerodynamically optimized cooling air shaft at the center of the battery casing through which there is a constant flow of air. To ensure optimum heat dissipation, the battery base has longitudinally arranged cooling ribs.
Interestingly, the battery casing in die-cast aluminum not only holds the cells with their special architecture but also the entire electronics unit for monitoring the cells. It also acts as a load-bearing chassis element.
The battery is charged via the integrated charging device, either at a regular household socket or a charging station. When the battery is completely flat, charging time ideally lasts less than three hours.
The car-type charging socket – currently the only one of its kind in an electrically powered two-wheel vehicle – is located behind a cover in the footwell. The charge cable required is housed in a storage compartment on the right-hand side of the footwell. It is fitted with a mains plug to fit the respective national system.
The fact that the charge socket is identical to the car standard has the advantage that the C evolution can be recharged at charging stations throughout the U.S. with integrated charge cable and standardized plug.
In order to reduce rolling friction and thus make the most efficient use of the electrical energy stored, the “C evolution” has lightweight tires. These are special Metzeler Feelgreen tires with optimized rolling resistance, in the sizes 120/70 R15 at front and 160/60 R15 at rear.
The tires were developed with two clear aims in mind: environmental compatibility and high efficiency based on minimizing rolling resistance; while at the same time providing a higher mileage. Rolling resistance was reduced by 25 percent when compared to the Metzeler Feelfree tires.
The BMW C at a glance:
• Innovative electric drive via drivetrain swing arm with liquid-cooled alternator, tooth belt and planetary gear
• 11 kw continuous output (homologation according to ECE R85) and 35 kW peak output
• 120 kph (74.5 mph ) maximum speed
• Range of up to 100 kilometers due to large battery capacity
• High-voltage battery with high capacity (8 kwh) and innovative air cooling
• Intelligent recuperation in coasting mode and when braking
• Synergy effects with BMW automobiles and electrical safety
to car standards
• Hybrid chassis with agile handling due to low center of gravity
• Powerful braking system with ABS
• Lightweight Metzeler Feelgreen tires
• Multifunctional TFT instrument cluster and LED daytime running light
• Innovative color concept and design