| 摘要 |
PURPOSE:To enhance the strength of a body frame by supporting the upper part of an engine by left and right main frames, supporting the rear part of the engine by left and right rear arm brackets, and providing the left and right main frames and a support shaft for supporting a rear arm nearly in isosceles triangular form. CONSTITUTION:In a body frame 2 for motorcycle, box left and right main frames made of sheet metals having vertically long sections are extended downward from the back of a head pipe 3 in such a manner as to be nearly linear in plane view. Left and right rear arm brackets 7 are extended downward from the rear ends of the main frames 4, and a rear arm 12 is supported by a support shaft 11 laid between the lower end parts of both the brackets 7 in such a manner as to be capable of vertically oscillating. An engine 25 is disposed under the left and right main frames 4, and the upper end of its cylinder head 29 is supported by the main frames 4, and the rear end of a power transmitting device 27 is supported by the rear arm brackets 7 through the support shaft 11. These left and right frames 4 and the pivot shaft 11 are provided in such a manner as to form nearly an isosceles triangle having the pivot shaft 11 as the bottom side in a plane view. |
