A mid drive system for an electric bicycle , the mid drive system comprising: a pedal shaft with pedals for a rider; a mid shaft residing parallel with the pedal shaft ; a first pedal shaft sprocket co-axial with the pedal shaft ; a first mid shaft sprocket co-axial with the mid shaft ; a first chain or belt rotationally couples the first pedal shaft sprocket to the first mid shaft sprocket ; the mid shaft driven by the pedal shaft through the first pedal shaft sprocket , the first chain or belt , and the first mid shaft sprocket , and through a first uni-directional bearing , the pedal shaft rotationally coupled to the mid shaft by the first uni-directional bearing when the pedal shaft drives the mid shaft , and decoupled from the mid shaft when the pedal shaft is not driving the mid shaft ; an electric motor rotationally coupled to drive the mid shaft ; a drive sprocket fixedly rotationally coupled to the mid shaft ; and a chain or belt coupling the drive sprocket to a bicycle wheel , characterized in that the electric motor is resided co-axially with the pedal shaft and rotationally decoupled to the pedal shaft by bearings ; a motor sprocket resides co-axial with the electric motor ; a second mid shaft sprocket reside co-axial with the mid shaft ; a second chain or belt rotationally couples the motor sprocket to the second mid shaft sprocket ; and the mid shaft is driven by the electric motor through the motor sprocket , the second chain or belt , and the second mid shaft sprocket , and through a second uni-directional bearing , the electric motor rotationally coupled to the mid shaft by the second uni-directional bearing when the electric motor drives the mid shaft , and decoupled from the mid shaft when the electric motor is not driving the mid shaft . a pedal shaft with pedals for a rider; a mid shaft residing parallel with the pedal shaft ; a first pedal shaft sprocket co-axial with the pedal shaft ; a first mid shaft sprocket co-axial with the mid shaft ; a first chain or belt rotationally couples the first pedal shaft sprocket to the first mid shaft sprocket ; the mid shaft driven by the pedal shaft through the first pedal shaft sprocket , the first chain or belt , and the first mid shaft sprocket , and through a first uni-directional bearing , the pedal shaft rotationally coupled to the mid shaft by the first uni-directional bearing when the pedal shaft drives the mid shaft , and decoupled from the mid shaft when the pedal shaft is not driving the mid shaft ; an electric motor rotationally coupled to drive the mid shaft ; a drive sprocket fixedly rotationally coupled to the mid shaft ; and a chain or belt coupling the drive sprocket to a bicycle wheel , characterized in that the electric motor is resided co-axially with the pedal shaft and rotationally decoupled to the pedal shaft by bearings ; a motor sprocket resides co-axial with the electric motor ; a second mid shaft sprocket reside co-axial with the mid shaft ; a second chain or belt rotationally couples the motor sprocket to the second mid shaft sprocket ; and the mid shaft is driven by the electric motor through the motor sprocket , the second chain or belt , and the second mid shaft sprocket , and through a second uni-directional bearing , the electric motor rotationally coupled to the mid shaft by the second uni-directional bearing when the electric motor drives the mid shaft , and decoupled from the mid shaft when the electric motor is not driving the mid shaft . <EOS>