Beautiful and Powerful: Audi's E-Bike Wörthersee

The prototype combines a electric and muscle power.

The airy frame boasts a low center of gravity and a compact overall volume. In this way, the e-bike is superbly agile at the sporty handling limits. The lithium-ion battery is incorporated into the frame and needs 2.5 hours to fully charge. On long trial tours, only a few simple steps are required to remove the battery and replace it with a charged one.

The frame and the swinging arm that holds the back wheel are made of carbon fiber-reinforced polymer (CFRP). The same material is used for the 26" wheels, which feature an innovative "Audi ultra blade" design with broad flat spokes for an optimized transmission of pedal power. "We were able to demonstrate with the choice of materials just how closely design goes hand in hand with expertise in ultra lightweight construction," Hendrik Schaefers comments.

The cyclist can choose between a total of five cycling modes – pure muscle power, the electric motor alone, or pedaling supported by the electric motor. In the "Pure" mode, the drive power is purely the product of the cyclist's legs, while in "Pedelec" mode you are supported by the electric motor that then makes speeds of up to 80 km/h (50 mph) possible and gives you a range of 50-70 kilometers (31-44 miles). If you select "eGrip", the Audi e-bike Wörthersee runs solely on the electric motor and can reach a top speed of 50 km/h (31 mph). The cyclist then controls forward momentum using a gripshift and can configure the power as desired using the computer.

The electric motor is located at the lowest point on the frame and drives the bottom bracket shaft directly. The maximum torque delivered to the rear wheel is 250 Nm (184.39 lb-ft). The electric motor generates a maximum output of 2.3 kW, a new world best for e-bikes. The complete bike excluding electrical components weighs in at 11 kg (24.25 lb), equivalent to a power-to-weight ratio of 9 kg (19.84 lb) per kilowatt, or 7 kg (15.43 lb) per horsepower – another record-breaking value.

When performing wheelies, an electronic control system support the rider when performing tricks and back-wheel biking. Different modes can be set using a smartphone or directly on the e-bike – either "Power Wheelie" mode, with adjustable wheelie angle for less skilled bikers or "Balanced Wheelie" mode for sporting challenges. In "Balanced Wheelie" mode, the electronic control system maintains the rider's balance, by compensating the biker's movements forwards or backwards via the electric motor. This means the rider can influence the bike's speed by shifting weight: if you lean forwards the bike picks up speed, and if you lean back it slows. You select "Training" mode if you want to keep your performance constant for training purposes.

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