Patent ID: 8550201

Claim:
A swing arm for a vehicle comprising: a pair of left and right arm portions extending in a longitudinal direction; a pivot portion formed on front ends of both arm portions; an axle support portion formed on rear ends of both arm portions in a state where the axle support portion pivotally supports an axle of a rear wheel; a cross portion arranged between both arm portions for connecting both arm portions behind the pivot portion wherein both arm portions are integrally formed with each other by molding; at least the cross portion is formed into a hollow shape with a pair of left and right support bosses adapted for supporting a shock absorber being integrally formed on a lower wall or an upper wall of the cross portion in an outwardly projecting manner; wherein the pivot portion is contiguously formed with both arm portions in a vehicle widthwise direction in a state where the pivot portion connects the front ends of both arm portions to each other; an opening portion whose peripheral portion is endlessly contiguously formed and whose upper and lower ends are opened is formed by the cross portion, the pivot portion and the pair of left and right arm portions; a pair of left and right recessed portions indented toward a support boss side, said pair of left and right recessed portions being formed on an inner surface of a wall wherein the support bosses are formed to project outwardly from the lower wall of the cross portion; and a pair of left and right reinforcing ribs positioned outside the recessed portions in the vehicle widthwise direction is integrally formed on the inner surface of the wall on which the support bosses are formed in a projecting manner toward the inside of the cross portion.