A bicycle braking system is basically provided with a bicycle braking device, a supplementary brake operating device and a brake maintaining arrangement. The bicycle braking device is movably between a non-brake applying position and a brake applying position for applying a braking force. The supplementary brake operating device is operatively coupled to operate the bicycle braking device. The supplementary brake operating device includes a rider operating arrangement that is operable by a rider between a non-braking position and at least one predetermined braking position. The brake maintaining arrangement is configured and arranged to hold the bicycle braking device in the brake applying position in response to movement of the rider operating arrangement to the predetermined braking position such that the braking force of the bicycle braking device is continually and consistently applied.