| 摘要 |
PURPOSE:To firmly protect a radiator by connecting an engine to main frames and down tubes, thereby forming a nearly square pyramid-shaped frame body by means of the main frames, the down tubes, and the engine, and arranging the radiator in the frame body. CONSTITUTION:In a body frame 2 of a motorcycle, right and left main frames 4 of vertical rectangular box type cross-section and made of sheet-metal are installed so that they are extended from a head tube 3 provided at the front part of the body frame back and downward nearly straight in a plane view, and a pair of right and left down tubes 13 are extended from the front ends of the main frames 4 back and straight downward. An engine 25 is installed below the right and left main frames 4, the upper end of an cylinder head 29 of the engine is clamped to the main frames 4, and the front end of a crank case 26 is clamped to the lower end of a down tube 13. Further, a square pyramid-shaped frame body 32 is formed by the main frames 4, down tubes 13, and the engine 25, a radiator 61 is arranged in the frame body 32, and the radiator 61 is thus protected from obstacles outside the vehicle. |
