Bicycle controller and bicycle control system including bicycle controller

A bicycle control device comprising:

• an electronic controller configured to control a motor that assists propulsion of a bicycle,
• the electronic controller being further configured to execute a motor output decreasing control to decrease output of the motor upon determining a shifting device performs a shifting action to change a transmission ratio of the bicycle,
• the electronic controller being further configured to end the motor output decreasing control before a predetermined period elapses upon determining that the shifting action is completed before the predetermined period has elapsed,
• the electronic controller being further configured to end the motor output decreasing control upon determining that the predetermined time period has elapsed in a case where the shifting action or the change in the transmission ratio is uncompleted even though the predetermined period has elapsed,
• the electronic controller being further configured to execute a determination as to whether the shifting action was successful based on a rotational speed of a crank of the bicycle, the electronic controller executing the determination as to whether the shifting action was successful only upon determining that a manual driving force inputted to the crank is greater than or equal to a predetermined value,
• the electronic controller being further configured to update the predetermined period in accordance with the change in the transmission ratio that is to be executed by the shifting action and based on a result of the determination as to whether the shifting action was successful.