Abstract: The present invention provides a silicon nitride sintered substrate capable of reducing contamination caused by a boron nitride powder or the like used as a releasing agent and problems in bonding strength and dielectric strength at the time of laminating metal layers or the like, where the contamination is caused by a network structure provided by a silicon nitride crystal formed on the surface of the substrate in an unpolished state after sintering a silicon nitride powder. The silicon nitride substrate in an unpolished state after sintering is a silicon nitride sintered substrate where a cumulative volume of pores having a diameter in a range of 1 to 10 ?m is not more than 7.0'10?5 mL/cm2 in a measurement by a mercury porosimetry. Preferably, Ra of the surface is not more than 0.6 ?m and arithmetic mean peak curvature (Spc) of a peak is not more than 4.5 [l/mm].

Abstract: A silicon nitride powder for sintering which, despite of its fine powdery form, shows a very small increase in the oxygen concentration with time and features excellent storage stability. The silicon nitride powder for sintering has a specific surface area of 5 to 30 m2/g, and is characterized by having a hydrophobicity (M value) of 30 or more and an increase in the oxygen concentration of 0.30% by mass or less after left to stand in the air of a humidity of 90% and 20° C. for 48 hours. The silicon nitride powder for sintering can be obtained by dry-pulverizing aggregated masses of the silicon nitride in an inert atmosphere in the presence of a silane coupling agent.

Abstract: A motorcycle frame includes a head pipe, a pair of front main frames, and a pair of rear main frames. The pair of front main frames separates in a vehicle width direction from the head pipe, extends toward a power engine that is located on a rear side of the head pipe, and includes power-engine fixing parts that are fixed to the power engine at positions that overlap with the power engine as viewed in the vehicle width direction. The pair of rear main frames extends rearward from the power-engine fixing parts of the pair of front main frames.

Abstract: A motorcycle includes a fuel tank, an engine, an air cleaner box, and an electrical component unit. The fuel tank stores a fuel. The engine is driven by the fuel stored in the fuel tank. The air cleaner box purifies air to be supplied to the engine. The electrical component unit includes two or more types of electrical components driven by electricity. The fuel tank and the engine are arranged vertically one above the other. At least part of the air cleaner box is positioned in a space between the fuel tank and the engine. The longitudinal position of at least part of the electrical component unit is more frontward than the rear end of the fuel tank and more rearward than the air cleaner box.

Abstract: A straddle vehicle is capable of discharging high-temperature outdoor air having passed through a radiator with high efficiency. A motorcycle 1 includes a radiator, a fan, and a fan shroud. The radiator lowers the temperature of a coolant by heat exchange between outdoor air and the coolant. The fan suctions outdoor air, to make the outdoor air hit the radiator arranged upstream in an outdoor air flow direction. The fan shroud covers at least part of the fan, and discharges high-temperature outdoor air, which is outdoor air suctioned by the fan and having passed through the radiator, to outside. The fan shroud has a discharge opening and an air guide. The discharge opening allows the high-temperature outdoor air to be discharged outside. The air guide guides the high-temperature outdoor air such that it is discharged through the discharge opening in a direction including a laterally outward component.

Abstract: A motorcycle includes a fuel tank, an engine, an air cleaner box, and an electrical component unit. The fuel tank stores a fuel. The engine is driven by the fuel stored in the fuel tank. The air cleaner box purifies air to be supplied to the engine. The electrical component unit includes two or more types of electrical components driven by electricity. The fuel tank and the engine are arranged vertically one above the other. At least part of the air cleaner box is positioned in a space between the fuel tank and the engine. The longitudinal position of at least part of the electrical component unit is more frontward than the rear end of the fuel tank and more rearward than the air cleaner box.

Abstract: A straddle vehicle is capable of discharging high-temperature outdoor air having passed through a radiator with high efficiency. A motorcycle 1 includes a radiator, a fan, and a fan shroud. The radiator lowers the temperature of a coolant by heat exchange between outdoor air and the coolant. The fan suctions outdoor air, to make the outdoor air hit the radiator arranged upstream in an outdoor air flow direction. The fan shroud covers at least part of the fan, and discharges high-temperature outdoor air, which is outdoor air suctioned by the fan and having passed through the radiator, to outside. The fan shroud has a discharge opening and an air guide. The discharge opening allows the high-temperature outdoor air to be discharged outside. The air guide guides the high-temperature outdoor air such that it is discharged through the discharge opening in a direction including a laterally outward component.

Abstract: A motorcycle frame includes a head pipe, a pair of front main frames, and a pair of rear main frames. The pair of front main frames separates in a vehicle width direction from the head pipe, extends toward a power engine that is located on a rear side of the head pipe, and includes power-engine fixing parts that are fixed to the power engine at positions that overlap with the power engine as viewed in the vehicle width direction. The pair of rear main frames extends rearward from the power-engine fixing parts of the pair of front main frames.

Abstract: A motorcycle comprises a rear wheel; a vehicle body frame including a front frame unit supporting a motor, and a rear frame unit supporting a seat; and a swing arm which is rotatably connected to the front frame unit and supports the rear wheel, wherein the rear frame unit includes: a front section which supports the seat and extends rearward from the front frame unit; a pair of right and left branch sections extending rearward from a rear end portion of the front section to be spaced apart from each other in a rightward and leftward direction; and a pair of rear sections which extend rearward from rear end portions of the pair of right and left branch sections, respectively, and are placed rightward and leftward relative to the rear wheel.

Abstract: A vehicle comprises a fender unit which covers an upper portion of a wheel from above; and a mounting member placed inward in a vehicle width direction relative to the fender unit and including a mounting section by which an accessory component is detachably mounted to a vehicle body, wherein the fender unit includes: a first cover member which has an opening through which the mounting section of the mounting member is exposed, and covers a portion of the mounting member which is other than the mounting section, from outside in the vehicle width direction; and a second cover member which is detachably mounted to the first cover member and covers the opening.

Abstract: In a straddle vehicle such as a motorcycle, a harness in an electric power supply system which is thick, has a great weight, and is not easily mounted can be reduced in length as much as possible so that a weight and cost can be reduced, and assembling work can be made easier. An air cleaner and a fuel tank are disposed at a relatively rearward position such that the air cleaner and the fuel tank are disposed behind and distant from the head pipe to provide an electric component mounting space between the air cleaner and the fuel tank, and the head pipe, and a regulator, a relay box and a fuse box are disposed in the electric component mounting space. The fuel tank is disposed at a relatively rearward position such that its rear end portion is positioned behind and below a rear end of a main frame.

Abstract: A motorcycle comprises a front wheel; a rear wheel; a seat; a vehicle body frame; a swing arm which supports the rear wheel such that the swing arm is vertically pivotable around a location at which the swing arm is connected to a front frame; and a rear suspension which connects the vehicle body frame to the swing arm via a link mechanism, wherein a seat frame includes a pair of rail sections having rear end portions which are placed to be spaced apart from each other on both sides in a vehicle width direction relative to the rear wheel and located above an axle of the rear wheel, and wherein the rear suspension is placed on one side in the vehicle width direction relative to a vehicle body center line extending in a forward and rearward direction and extends in the forward and rearward direction.

Abstract: A motorcycle comprises a front wheel; a rear wheel; a seat; a vehicle body frame; a swing arm which supports the rear wheel such that the swing arm is vertically pivotable around a location at which the swing arm is connected to a front frame; and a rear suspension which connects the vehicle body frame to the swing arm via a link mechanism, wherein a seat frame includes a pair of rail sections having rear end portions which are placed to be spaced apart from each other on both sides in a vehicle width direction relative to the rear wheel and located above an axle of the rear wheel, and wherein the rear suspension is placed on one side in the vehicle width direction relative to a vehicle body center line extending in a forward and rearward direction and extends in the forward and rearward direction.

Abstract: A motorcycle comprises a rear wheel; a vehicle body frame including a front frame unit supporting a motor, and a rear frame unit supporting a seat; and a swing arm which is rotatably connected to the front frame unit and supports the rear wheel, wherein the rear frame unit includes: a front section which supports the seat and extends rearward from the front frame unit; a pair of right and left branch sections extending rearward from a rear end portion of the front section to be spaced apart from each other in a rightward and leftward direction; and a pair of rear sections which extend rearward from rear end portions of the pair of right and left branch sections, respectively, and are placed rightward and leftward relative to the rear wheel.

Abstract: A vehicle comprises a fender unit which covers an upper portion of a wheel from above; and a mounting member placed inward in a vehicle width direction relative to the fender unit and including a mounting section by which an accessory component is detachably mounted to a vehicle body, wherein the fender unit includes: a first cover member which has an opening through which the mounting section of the mounting member is exposed, and covers a portion of the mounting member which is other than the mounting section, from outside in the vehicle width direction; and a second cover member which is detachably mounted to the first cover member and covers the opening.

Abstract: In a straddle vehicle such as a motorcycle, a harness in an electric power supply system which is thick, has a great weight, and is not easily mounted can be reduced in length as much as possible so that a weight and cost can be reduced, and assembling work can be made easier. An air cleaner and a fuel tank are disposed at a relatively rearward position such that the air cleaner and the fuel tank are disposed behind and distant from the head pipe to provide an electric component mounting space between the air cleaner and the fuel tank, and the head pipe, and a regulator, a relay box and a fuse box are disposed in the electric component mounting space. The fuel tank is disposed at a relatively rearward position such that its rear end portion is positioned behind and below a rear end of a main frame.

Abstract: A vehicle body frame of a motorcycle comprises a front frame portion extending rearward from a head pipe; and a rear frame portion extending downward or rearward from a rear end of the front frame portion. The front frame portion includes at least a pair of right and left frame members. A forward portion of the rear frame portion is a lumbar frame having a closed cross-section structure portion in which a pair of right and left steel plates and are joined together. Devices such as a canister, and an ABS unit, are easily mounted in spaces lateral relative to the lumbar frame having a reduced width, while ensuring a sufficient stiffness.

Abstract: A handlebar support structure for sandwiching a steering handlebar (12) between a lower holder (25) and an upper holder (28) includes an instrument mounting area (30) for supporting an instrument panel unit (14) fitted removably thereto and a shield mounting area (32) for supporting a windshield (16) fitted removably thereto. The instrument mounting area (30) and the shield mounting area (32) are formed integrally with each other. The instrument mounting area (30) and the shield mounting area (32) altogether represent a forwardly pursed shape along a direction conforming to a forwardly tilted direction (D).

Abstract: In a vehicle body frame including a front frame portion extending rearward from a head pipe, and a rear frame portion extending downward or rearward from a rear end of the front frame portion, a forward portion of the rear frame portion, for example, a lumbar frame, includes a reduced-width portion overlapping with a vehicle body center line extending in a forward and rearward direction when viewed from above, and having a shape in which a width in a rightward and leftward direction is smaller than a length in an upward and downward direction. Devices incorporated into the motorcycle, such as a canister, a battery, an ABS unit, and a suspension unit, are laid out in spaces lateral relative to the reduced-width portion. Thus, the devices can be mounted to the vehicle body frame easily and efficiently.

Abstract: A straddle vehicle includes an engine; an air cleaner including an air cleaner box forming a passage through which air is supplied to the engine and an air filter for cleaning the air flowing through the passage; and a first electric component positioned laterally relative to the air cleaner box.