An automatic shifting device for a bicycle is disclosed. The device may include a shifting actuator to activate the gearshift mechanism, a computing unit connected to the shifting actuator, an operator control/display unit connected to the computing unit, an inclination angle sensor, and a velocity sensor. The operator control/display unit may receive a first input value of a gear speed of the gearshift mechanism for starting on a level underlying surface; a second input value of a velocity of the bicycle at which shifting into a maximum gear speed of the gearshift mechanism takes place on a level underlying surface; and a third input value of a velocity of the bicycle at which shifting into a maximum gear speed for this terrain inclination takes place on an underlying surface with a positive terrain inclination. An individualized shifting algorithm based on the input values may be stored in the computing unit.