A bicycle seatpost system comprises an electric actuator, a remote controller, and a seatpost controller. The seatpost controller is configured to control the electric actuator to change a state of the bicycle seatpost assembly to an adjustable state based on one of a first control signal and a second control signal. The remote controller includes a first operating part configured to receive a first user input and a second operating part configured to receive a second user input. The remote controller is configured to generate the first control signal having a constant signal length regardless of an operation period of the first user input. The remote controller is configured to generate the second control signal having a signal length corresponding to the operation period of the second user input.