Patent ID: 8534407

Claim:
A seat rail ( 30 ) of a motorcycle which includes a pair of left and right rail sections ( 45 L, 45 R) extending rearward from a vehicle body frame ( 11 ) for supporting thereon a seat ( 12 , 13 ), the seat rail being a magnesium-alloy cast seat rail, each of the left and right rail sections having a first groove section ( 64 ) formed in an upper inner side region thereof as viewed in a vehicle width direction and opening downward, and a second groove section ( 65 ) formed in a lower, outer side region thereof as viewed in the vehicle width direction and opening upward, the second groove section having a drainage hole ( 71 ) formed in a bottom portion ( 69 ) thereof for draining accumulated water in a downward direction, each of the left and right rail sections having a lower surface, and an annular protruding portion ( 72 ) formed integrally on the lower surface so as to surround a lower opening end of the drainage hole, the second groove section having an outer wall portion ( 70 ) extending upward from an outer side region, in the vehicle width direction, of the bottom portion, the outer wall portion having a boss ( 81 ) formed integrally thereon so that a distal end of a push pin ( 82 ) abuts against the boss at a time of mold release during manufacturing of the seat rail.