Frameless motorcycle

Claim 2

A frameless motorcycle (1) comprising: a front wheel (10); a suspension (7, 8, 9, 11, 12, 13, 5a, 5b) for said front wheel (10), said suspension including an upper front swing arm (7) and a lower front swing arm (8) cooperating with each other to support said front wheel (10) at the front ends thereof; a rear wheel (15); an engine (4); and an attachment member (3) consisting of a bottom wall portion (6) and left and right side wall portions 5, 5 continued to the left and right ends of said bottom wall portion (6) when viewed from ahead of the vehicle; said attachment member (3) covering the lower portion of said engine (4) attached thereto; both of said front swing arms (7,8) being pivotably attached at rear end parts thereof to said side wall portions (5,5) of said attachment member (3); and the parts of said lower front swing arm (8) attached to said side wall portions (5,5) of said attachment member (3) being offset inwardly of the vehicle by a predetermined distance (l) from the parts of said upper front swing arm (7) attached to said side wall portions (5,5) of said attachment member (3).

Claim 3

A frameless motorcycle according to claim 1, further comprising: a suspension (14, 16, 17, 18) for said rear wheel (15), including a rear swing arm (14) for supporting said rear wheel (15) at the rear end thereof; and said rear swing arm (14) is pivotably attached at the front end thereof to said side wall portions (5, 5) of said attachment member (3).

Claim 4

A frameless motorcycle according to claim 1, wherein: said bottom wall portion (6) of said attachment member (3) is formed with an opening (3a) for fitting therein an oil pan (4c) of said engine (4).

Claim 5

A frameless motorcycle (1) comprising: a front wheel (10); a suspension (7, 8, 9, 11, 12, 13, 5a, 5b) for said front wheel (10), said suspension including an upper front swing arm (7) and a lower front swing arm (8) cooperating with each other to support said front wheel (10) at the front ends thereof; a rear wheel (15); an engine (4); and an attachment member (3) consisting of a bottom wall portion (6) and left and right side wall portions (5,5) continued to the left and right ends of said bottom wall portion (6) when viewed from ahead of the vehicle; said attachment member 3 having said engine (4) attached thereto; both of said front swing arms (7,8) being pivotably attached at rear end parts thereof to said side wall portions (5,5) of said attachment member (3); and the parts of said lower front swing arm (8) attached to said side wall portions (5,5) of said attachment member (3) being offset inwardly of the vehicle by a predetermined distance (l) from the parts of said upper front swing arm (7) attached to said side wall portions (5,5) of said attachment member (3); said side wall portions (5, 5) of said attachment member (3) comprise lower side wall parts (5e, 5e) upwardly and slightly sidewardly extending from the left and right ends of said bottom portion (6), inclined wall parts (5d, 5d) transversely outwardly extending by said predetermined distance (l), while slightly ascending, continuously from said lower side wall parts (5e, 5e), and upper side wall parts (5f, 5f) upwardly extending from the left and right ends of said inclined wall parts (5d, 5d), respectively, when viewed from ahead of the vehicle; and said rear end parts of said upper and said lower front swing arms (7, 8) are pivotably attached to said upper side wall parts (5f, 5f) and said lower side wall parts (5e, 5e) of said side wall portions (5, 5) of said attachment member (3), respectively.

Claim 6

A frameless motorcycle (1) comprising: a front wheel (10); a suspension (7, 8, 9, 11, 12, 13, 5a, 5b) for said front wheel (10), said suspension including an upper front swing arm (7) and a lower front swing arm (8) cooperating with each other to support said front wheel (10) at the front ends thereof; a rear wheel (15); an engine (4); and an attachment member (3) consisting of a bottom wall portion (6) and left and right side wall portions (5,5) continued to the left and right ends of said bottom wall portion (6) when viewed from ahead of the vehicle; said attachment member 3 having said engine (4) attached thereto; both of said front swing arms (7,8) being pivotably attached at rear end parts thereof to said side wall portions (5,5) of said attachment member (3); and the parts of said lower front swing arm (8) attached to said side wall portions (5,5) of said attachment member (3) being offset inwardly of the vehicle by a predetermined distance (l) from the parts of said upper front swing arm (7) attached to said side wall portions (5,5) of said attachment member (3); said side wall portions (5, 5) of said attachment member (3) comprise lower side wall parts (5e, 5e) upwardly and slightly sidewardly extending from the left and right ends of said bottom portion (6), inclined wall parts (5d, 5d) transversely outwardly extending by said predetermined distance (l), while slightly ascending, continuously from said lower side wall parts (5e, 5e), and upper side wall parts (5f, 5f) upwardly extending from the left and right ends of said inclined wall parts (5d, 5d), respectively, when viewed from ahead of the vehicle; and said rear end parts of said upper and said lower front swing arms (7, 8) are pivotably attached to said upper side wall parts (5f, 5f) and said lower side wall parts (5e, 5e) of said side wall portions (5, 5) of said attachment member (3), respectively.