BMW just released official pictures of its co-developed three-wheeled, natural-gas powered micro-car called CLEVER (Compact Low Emission VEhicle for URban Transport). Although nothing official yet, but this concept that was funded by the European Commission (Fifth Framework Programme) could base the C1 successor, marrying the worlds of cars and motorcycles. Partners in the C.L.E.V.E.R project included:
- Technical University of Berlin, Institute for Land and Sea Transport (TUB), Berlin, Germany
- Cooper-Avon Tyres Ltd, Melksham, Great Britain
- ARC Leichtmetall Kompetenzzentrum Ranshofen GmbH (LKR), Ranshofen, Austria
- TAKATA-PETRI AG, Berlin, Germany
- University of Bath, Department of Mechanical Engineering, Institute for Power Transmission and Motion Control, Bath, Great Britain
- Universität für Bodenkultur Vienna, Institute of Transport, Vienna, Austria
- WEH GmbH, Illertissen, Germany
The CLEVER concept, a €3.3 million (US$3.9 million) effort, is an enclosed two-seater that combines the safety of a microcar, and the maneuverability of a motorcycle, while being less polluting than other vehicles as it runs on compressed natural gas.
Its strengthened frame will protect the driver in a crash and the vehicle will have a top speed of approximately 50 mph. The 230cc BMW engine—modified by Institut Français du Pétrole (IFP) to use natural gas—produces 12.5 kW (17 hp) of power and maximum torque of 15.5 Nm at 6,300 rpm.
Fuel consumption is estimated to be 2.4 liters/100 km gasoline equivalent (98 mpg US), with 59.5 g/km of CO2 emissions. The compressed natural gas is stored in two removable gas bottles providing a range of 150 km (93 miles).
A problem with three-wheel vehicles with a symmetrical wheel layout is the tipping moment when cornering, which cannot be controlled at high speeds if the vehicle has a short wheelbase. To solve this problem the vehicle’s center of gravity can be moved towards the center of the corner—just as a motorcycle does when it corners.
The do this, the vehicle is a cabin tilter, with the system designed by the University of Bath. The cabin with the front wheel is connected to the power unit and the two rear wheels by a pivot bolt. The rotary movement of the cabin is produced by two hydraulic cylinders (actuators) that are installed between the cabin and the power unit. The actuators create the rotary angle of the cabin of +/-45° relative to the vertical power unit.