A bicycle electronic system is described comprising a first manual command management unit having a casing configured for being fixed at a handgrip of a bicycle handlebar, comprising at least one first manually actuatable switch, a first processor and a first wireless communication device, wherein the first manual command management unit further comprises a circuit for supplying power to the first processor and the first wireless communication device, the power supply circuit comprising a battery power supply source and/or being configured for absorbing energy from a radiofrequency electromagnetic field generated within the system.