A cantilever brake of bicycle is provided with a triangular cable stop including first, second and third corner attachments and a wheel between the first and second corner attachments; a first pivot member including a first trough; a first cable passing through the first corner attachment, the wheel, and the second corner attachment to be fastened at the first pivot; a second pivot member including a second trough; a second cable having one end fastened in the third corner attachment and the other end fastened in the second pivot member; a first brake arm releasably pivotably secured to the first trough and including two opposite first projections and a spring actuated first adjustment knob distal the first projections; and a second brake arm releasably pivotably secured to the second trough and including two opposite second projections and a spring actuated second adjustment knob distal the second projections.