Abstract: A stabilizer having a tubular shape is provided so as to extend in a widthwise direction of a vehicle and coupled to a suspension arm at opposite end portions of the stabilizer. Each of the opposite end portions includes: a first large-diameter bar portion having an outside diameter greater than an outside diameter of an intermediate portion of the stabilizer; and a second large-diameter bar portion having an outside diameter greater than the outside diameter of the first large-diameter bar portion and having a wall thickness greater than a wall thickness of the intermediate portion.

Abstract: A handlebar formed from a metal hollow pipe and having a generally uniform peripheral wall thickness along its entire length, including a longitudinal center portion, first and second end portions having a smaller outer diameter than that of the longitudinal center portion, and first and second, tapered intermediate portions connecting the center portion to the first and second end portions, respectively. The first and second, tapered intermediate portions and/or the first and second end portions are bent symmetrically with respect to the longitudinal center portion. The handlebar is produced by bending a hollow straight metal pipe, placing the resulting bent pipe between molds and feeding a pressurized liquid into the bent pipe while axially compressing the bent pipe to cause the peripheral wall of the bent pipe to plastically expand into conformity with a mold cavity defined by the molds.

Abstract: A method for producing light-weight twin tank rails of a two-wheeled vehicle including bending a rear portion of each of a pair of tubular rails downward using a roll bending machine to form a pair of primarily bent tubular rails. Each of the primarily bent tubular rails is bent using a press molding machine at its front portion to form a pair of secondarily bent tubular rails. Then, a pressurized liquid is fed into each of the second secondarily bent tubular rails while maintaining the secondarily bent tubular rail in the mold cavity of the press molding machine to plastically deform the peripheral wall thereof into conformity with the mold cavity of the corresponding press molding machine.