Abstract: The vehicle can include a power transmission system for transmitting power of an internal combustion engine to drive wheels through transmissions and a parking brake system for restraining rotation of the drive wheels by engaging with a part of the power transmission system. The parking brake system for the vehicle can also include a parking drive mechanism which operates a restraining member, by turning of an input shaft of a shift drive mechanism for changing the shift position in the transmission, so as to restrain rotation of transmission gear shafts, and thereby establish a parking brake state. In the parking brake system, a shift cable connected to the input shaft is connected to a parking operation lever.

Abstract: A drum type-variable speed drive wherein a spring bearing member, which is restricted from moving in the axial direction of departing from a shift fork by a locking member fixed to a shift fork shaft, is pivotally supported by the shift fork shaft. A lost motion spring is interposed between the spring bearing member and the shift fork. Movement of the shift fork shaft in the axial direction caused by rotation of a shift drum presses the spring bearing member through the locking member, whereby the spring load of the lost motion spring acts on the shift fork.

Abstract: The vehicle driving force transmission structure of a power unit can include a main transmission having a transmission shaft group and parallel to a crankshaft and provided in a crankcase on the side of the crankshaft. The transmission structure can also include a large rotational body provided at an end of the crankshaft, and an auxiliary transmission provided as a separate body from and connecting to the main transmission. The auxiliary transmission has a transmission shaft group parallel to the transmission shaft group of the main transmission and disposed so as to form a periphery of the large rotational body. The auxiliary transmission includes a transmission driving mechanism disposed below the large rotational body.

Abstract: A transmission partly overlapping clutches as viewed from an axial direction of a crankshaft is disposed below an inclined cylinder axis of an engine main body. A speed change actuator is disposed in a position such that the transmission is interposed between the speed change actuator and the crankshaft. An exhaust pipe connected to a lower side wall of a cylinder head is extended so as to pass above the transmission and partly overlap an upper portion of the speed change actuator as viewed from the axial direction of the crankshaft.

Abstract: A shift drum structure for a drum-type transmission in which a shift fork moving on a shift fork shaft in an axial direction while guided by a guide groove in response to a turn of a shift drum, changes speeds by sliding a shifter member on a transmission driving shaft pivotally supporting a transmission gear, the shift drum. The shift drum includes a cylindrical drum main body and drum spindles projecting outward from drum end walls on the respective two sides of the drum main body, and the guide groove formed in an outer peripheral surface of the drum main body in a circumferential direction, wherein in the shift drum, a work groove is formed in the outer peripheral surface of the drum main body from one end surface to an opposite end surface of the drum main body, or to the guide groove near the opposite end surface.

Abstract: A clutch actuator and a speed change actuator are disposed so as to be adjacent to each other on one side of an engine main body along the axis of a crankshaft. The clutch actuator is provided with a manual clutch operating part capable of being manually operated. The speed change actuator is provided with a manual speed change operating part capable of being manually operated.

Abstract: A drum type-variable speed drive wherein a spring bearing member, which is restricted from moving in the axial direction of departing from a shift fork by a locking member fixed to a shift fork shaft, is pivotally supported by the shift fork shaft. A lost motion spring is interposed between the spring bearing member and the shift fork. Movement of the shift fork shaft in the axial direction caused by rotation of a shift drum presses the spring bearing member through the locking member, whereby the spring load of the lost motion spring acts on the shift fork.

Abstract: The vehicle driving force transmission structure of a power unit can include a main transmission having a transmission shaft group and parallel to a crankshaft and provided in a crankcase on the side of the crankshaft. The transmission structure can also include a large rotational body provided at an end of the crankshaft, and an auxiliary transmission provided as a separate body from and connecting to the main transmission. The auxiliary transmission has a transmission shaft group parallel to the transmission shaft group of the main transmission and disposed so as to form a periphery of the large rotational body. The auxiliary transmission includes a transmission driving mechanism disposed below the large rotational body.

Abstract: A clutch actuator and a speed change actuator are disposed so as to be adjacent to each other on one side of an engine main body along the axis of a crankshaft. The clutch actuator is provided with a manual clutch operating part capable of being manually operated. The speed change actuator is provided with a manual speed change operating part capable of being manually operated.

Abstract: A transmission partly overlapping clutches as viewed from an axial direction of a crankshaft is disposed below an inclined cylinder axis of an engine main body. A speed change actuator is disposed in a position such that the transmission is interposed between the speed change actuator and the crankshaft. An exhaust pipe connected to a lower side wall of a cylinder head is extended so as to pass above the transmission and partly overlap an upper portion of the speed change actuator as viewed from the axial direction of the crankshaft.

Abstract: The vehicle can include a power transmission system for transmitting power of an internal combustion engine to drive wheels through transmissions and a parking brake system for restraining rotation of the drive wheels by engaging with a part of the power transmission system. The parking brake system for the vehicle can also include a parking drive mechanism which operates a restraining member, by turning of an input shaft of a shift drive mechanism for changing the shift position in the transmission, so as to restrain rotation of transmission gear shafts, and thereby establish a parking brake state. In the parking brake system, a shift cable connected to the input shaft is connected to a parking operation lever.

Abstract: A shift drum structure for a drum-type transmission in which a shift fork moving on a shift fork shaft in an axial direction while guided by a guide groove in response to a turn of a shift drum, changes speeds by sliding a shifter member on a transmission driving shaft pivotally supporting a transmission gear, the shift drum. The shift drum includes a cylindrical drum main body and drum spindles projecting outward from drum end walls on the respective two sides of the drum main body, and the guide groove formed in an outer peripheral surface of the drum main body in a circumferential direction, wherein in the shift drum, a work groove is formed in the outer peripheral surface of the drum main body from one end surface to an opposite end surface of the drum main body, or to the guide groove near the opposite end surface.