A bicycle brake apparatus comprising: a first brake arm including: a first brake arm mounting portion for pivotably mounting the brake arm to a bicycle frame member to pivot around a first pivot axis of a first pivot axle and a first control interface portion; a second brake arm including: a second brake arm mounting portion for pivotably mounting the brake arm to a bicycle frame member to pivot around a second pivot axis of a second pivot axle and a second control interface portion; and a piston unit including: a housing with a fluid chamber, wherein the housing has a first axial end and a second axial end, a piston movably disposed within the chamber, and an output shaft coupled to the piston and extending from the first axial end of the housing; wherein the first control interface portion of the first brake arm is coupled to the output shaft; and wherein the second control interface portion of the second brake arm is coupled to the housing between the first axial end of the housing and the second axial end of the housing, characterized in that the bicycle brake apparatus further comprises: an adjusting member disposed at the output shaft outside of the chamber, wherein the adjusting member adjusts a position of the output shaft relative to at least one of the housing or the first control interface portion of the first brake arm, wherein the output shaft is slidably coupled to the first control interface portion. a first brake arm including: a first brake arm mounting portion for pivotably mounting the brake arm to a bicycle frame member to pivot around a first pivot axis of a first pivot axle and a first control interface portion; a first brake arm mounting portion for pivotably mounting the brake arm to a bicycle frame member to pivot around a first pivot axis of a first pivot axle and a first control interface portion; a second brake arm including: a second brake arm mounting portion for pivotably mounting the brake arm to a bicycle frame member to pivot around a second pivot axis of a second pivot axle and a second control interface portion; and a second brake arm mounting portion for pivotably mounting the brake arm to a bicycle frame member to pivot around a second pivot axis of a second pivot axle and a second control interface portion; and a piston unit including: a housing with a fluid chamber, wherein the housing has a first axial end and a second axial end, a piston movably disposed within the chamber, and an output shaft coupled to the piston and extending from the first axial end of the housing; a housing with a fluid chamber, wherein the housing has a first axial end and a second axial end, a piston movably disposed within the chamber, and an output shaft coupled to the piston and extending from the first axial end of the housing; wherein the first control interface portion of the first brake arm is coupled to the output shaft; and wherein the second control interface portion of the second brake arm is coupled to the housing between the first axial end of the housing and the second axial end of the housing, characterized in that the bicycle brake apparatus further comprises: an adjusting member disposed at the output shaft outside of the chamber, wherein the adjusting member adjusts a position of the output shaft relative to at least one of the housing or the first control interface portion of the first brake arm, wherein the output shaft is slidably coupled to the first control interface portion. an adjusting member disposed at the output shaft outside of the chamber, wherein the adjusting member adjusts a position of the output shaft relative to at least one of the housing or the first control interface portion of the first brake arm, wherein the output shaft is slidably coupled to the first control interface portion.