Electric bicycle drive unit and energy storage device

An electric bicycle drive unit for arrangement in a bottom bracket area of a bicycle frame, the drive unit comprising:

• a bottom bracket assembly with a bottom bracket shaft,
• an electric motor device with a motor shaft which is arranged coaxially or axially parallel with respect to the bottom bracket shaft,
• an energy storage device for supplying energy to the motor device,
• wherein the energy storage device, in a state of the drive unit installed in the bicycle frame and ready for operation, can be arranged at least to a substantial extent in a down tube of the bicycle frame, the down tube having a closed tube cross section, and
• wherein the energy storage device is configured to be removable from the bicycle frame in a removal direction extending coaxially with respect to a longitudinal axis of the down, tube;
• wherein two frame interface arrangements define a rear fixation axis and a front support axis arrangement with a front fixation axis;
• and
• wherein, in the state of the drive unit in which it is installed into the bicycle frame ready for operation, the two fixation axes are arranged in front of a vertical plane which contains a rotatory axis of the bottom bracket shaft.