Cable routing through Alpha One is easy, straightforward, and hides cables from the wind. The brake cables route internally through the wing. The front brake cable exits the opening at the bottom of the bar, and you can route full housing or hydraulic line through the hole, or route bare cable via the included removable cable stop. The rear brake cable exits the back of the bar under the cable cover. Shifter cables or wires exit your extensions, and enter the stem cavity. They are then hidden under the cable cover, by entering the cable port just behind the Monopost. You can route all your cables and then hide them, rather than have to execute a convoluted routing operation with the cover already in place. The images below show routing with Shimano Di2 wires, and full brake housing. And yes, the 5-port Di2 junction does fit in the stem cavity. It's a tight fit, but it works. The routing would be the same for mechanical cables, except that the shifter cables would not be taped to the back of the Monopost, instead taking a slacker route to the cable port behind the Monopost. Cables and wires route into the stem cavity The 5-port Di2 junction fits snugly inside All cables, wires, and junctions tucked inside the stem Di2 wires snugged up to the Monopost, for fully-hidden cables