To make a generator out of a bicycle, Devon will need two magnets and coil of wire.
There is a close knit relationship between magnetism and electricity. Electricity can be generated by a wire changing flux in the presence of a magnetic field.
The magnets provide magnetic field for the process.
The coil of wire is placed in between the magnetic field generated by the magnets.
The bicycle pedal is connected to the set up to turn the wire in between the magnetic fields.