Abstract: A controller and a control method of a motorcycle brake system capable of meeting requests of downsizing, cost cut, simplification, and the like, and a motorcycle brake system including such a controller are obtained. In the controller and the control method of the motorcycle brake system and the motorcycle brake system according to the invention, a positive gradient G that corresponds to a lean angle A obtained during turning of a motorcycle is set, and, when an initiation reference is satisfied, a braking force suppression operation to increase braking forces, which are generated by wheel braking mechanisms, in the positive gradient G is initiated.

Abstract: A controller and a control method of a brake system for a motorcycle are obtained, the controller and the control method capable of improving behavior stability of a motorcycle at a time when a road surface is a steep upward slope. The invention also obtains a brake system for a motorcycle that includes such a controller. In the controller and the control method of the brake system for a motorcycle and in the brake system for a motorcycle according to the invention, in the cases where it is determined that a user's operation of a first brake operation section 11 is present and it is determined that the motorcycle 100 is in a slip-down state where the motorcycle travels backward while a front wheel 3 is braked when the road surface is the upward slope, an emergency braking action that causes a rear-wheel brake mechanism 14 to generate a braking force that brakes a rear wheel 4 is executed.