Abstract: A brake apparatus for a two-wheeled vehicle includes a hydraulic brake, which receives a hydraulic force to thereby generate a braking force, and a braking force control unit, which controls the braking force by increasing or decreasing the hydraulic pressure. The two-wheeled vehicle includes an engine disposed between a front wheel and a rear wheel. The engine includes a crankcase disposed downward thereof and a cylinder extending upwardly from a front portion of the crankcase. The braking force control unit is disposed in a space surrounded by the cylinder at a position forward thereof and the crankcase at a position downward thereof, respectively. The brake apparatus for a two-wheeled vehicle is capable of promoting enhanced maneuverability, achieving sufficient durability performance, and improving electric connection performance.

Abstract: A mold and a die-cast manufacturing method for the die-cast product, in which a main frame which is contiguously formed with a head pipe constitutes a portion of a hollow light-weight-metal-made vehicle-body frame. The mold includes a core for forming an inner space of the hollow vehicle-body frame. The core includes a core body and a plurality of splints mounted on the core body, the splints having approximately elliptical cross-sectional shapes. The long axes direction of ellipses of the splints are set parallel to a mold split surface of the mold. As a result, measurement of the positional accuracy of the splints is facilitated, a clearance between the splint and the mold can decrease by increasing the dimensional accuracy of splint mounting portions of the mold based on sizes of the splints, and the frame can be manufactured with high dimensional accuracy.

Abstract: An intake duct structure having an intake path extending forwardly from a cleaner box, penetrating through an area near a head pipe of a vehicle body frame, and opening at a front end portion of a front cowl. During low speed operation of the engine, an intake valve closes a main intake path MR from a front end intake port and opens a sub-intake path SR from a lower portion intake port. On the other hand, during high speed operation of the engine, the intake valve opens the main intake path MR and closes the sub-intake path SR. The lower portion intake port opens forward of a head pipe inside a front cowl and obliquely downwardly toward the rear. With this arrangement, entry of rainwater into the intake path can be minimized during low speed operation of the engine.

Abstract: To easily secure a welding length when an opening is formed at a portion in the vicinity of a joint portion between a head pipe portion and a main frame portion. A front opening penetrating through a vehicle body frame across a head pipe portion and a main frame portion. A rib extending across the front opening along a front parting plane of the vehicle body frame. The rib being divided along the front parting plane and the edge portions of the divided rib portions opposing the outer periphery of the main frame portion are integrally joined.

Abstract: To arrange a steering damper behind a head pipe in a compact manner while suppressing the influence of the steering damper on an intake duct which penetrates the vicinity of head pipes of a vehicle body frame. A steering damper is arranged between left and right main frames of a vehicle body frame and, at the same time, is arranged above or below an intake duct which penetrates the vicinity of a head pipe of the vehicle body frame.

Abstract: A frame structure for a motorcycle includes a front fork which journals a front wheel and that is capable of being steered and supported by a head pipe. Front end portions of a pair of right and left pipe members are connected contiguously to the head pipe and extend downwardly and rearwardly from the head pipe. The pair of right and left pipe members each have a substantially prismatic cross sectional shape and are each bent at their longitudinally intermediate portions so as to be outwardly convex with respect to the sides of the motorcycle frame. An engine is disposed between lower portions of both pipe members in an engine mounting space. The present invention narrows the distance between the upper portions of the right and left pipe members and effectively increases the space between the lower portions of the pair of right and left pipe members.

Abstract: Piping associated with interlocked brakes for front and rear wheel brakes is to be simplified to improve maintainability and provide a brake system suitable particularly for a two-wheeled motor vehicle satisfying racing specifications. A braking system includes hydraulic brakes with three hydraulic systems which are a lever hydraulic system for a front wheel brake, an interlocked hydraulic system for a rear wheel brake and a pedal hydraulic system. A pressure sensor detects a hydraulic pressure in the lever hydraulic system and outputs the detected signal to a control unit in the interlocked hydraulic system through an electric wire. The control unit controls the operation of a motor, thereby causing a hydraulic pressure to be developed in a submaster cylinder, which hydraulic pressure is fed to the rear wheel brake through a control valve.