All housing--brakes as well as shifter--runs internally within the frame, offering a nice, clean look. It is a bit of a hassle if the brakes need to be swapped in a hurry. Unless you are running Formula's speed lock system. Again, Andrew, Ragot's mechanic, adds a bit of a more robust housing to this somewjhat vulnerable portion of the disc brake hose before it wraps around the BB shell and goes into the chainstay.