A bicycle braking system comprises an operating device, a braking device, a sensing device, and an adjusting device. The operating device includes an operating member configured to be operated by a user. The braking device is configured to apply a braking force to a movable member of a bicycle in response to an operation of the operating member. The braking device includes at least one friction member configured to contact the movable member. The sensing device is configured to sense first information relating to an operation amount of the operating member and second information relating to an operating force of the operating member. The adjusting device is configured to adjust a position of the at least one friction member based on the first information and the second information.