Pivot mechanism in a brake lever of bicycle for ensuring a reliable actuation of brake

A brake operating device for a bicycle, comprising:

• a housing mounted on a handlebar and comprising a channel, a first hole, a second hole spaced from the first hole, a bifurcated opening between the first hole and the second hole, a fluid reservoir, and a reservoir cover secured to the fluid reservoir;
• a spring actuated brake transmission mechanism disposed in the channel;
• a hydraulic brake lever comprising a stepped-diameter tunnel and a projecting push member proximate to the tunnel, the projecting push member engaging the spring actuated mechanism;
• and
• a pivot assembly comprising a first retaining member including a first sleeve disposed in the first hole and having one end engaging the reservoir cover, and an annular first flange at the other end of the first sleeve and engaging an inner surface of the tunnel;
• a second retaining member including a cup disposed in the second hole and having a bottom through hole, and an annular second flange around mouth of the cup, the second flange engaging the inner surface of the tunnel;
• and a cylindrical pivot disposed in the first retaining member, the tunnel, and the second retaining member for rotatably supporting the hydraulic brake lever on the housing.