A brake caliper assembly includes a brake caliper pivotally mounted to a shaft extending from the front fork of a bicycle, a cam member fixedly received in the frame portion of the caliper and fixedly mounted to the shaft. A pushing member is pivotally received in the frame portion with the lower end engaged with the cam member. A supporting member is biasedly connected to the brake caliper and the brake pad is fixedly connected to the supporting member. The rear side of the supporting member contacts the upper end of the pushing member. A bolt threadedly extends through the bottom of the frame portion so as to contact the cam member so that when rotating the bolt the caliper is pivoted about the shaft and the supporting member is pushed and pivoted by the pushing member which is pivoted by the cam member.