The Trail Tech
computer uses a reed switch
and magnet for its speed sensor. I used some high-temp epoxy to mount the magnet in the hole of one of the brake disk buttons.
With the magnet fixed I tried different locations for the reed switch and decided that mounting at the top of the caliper adapter gave the best cable routing while giving a good signal. I drilled and tapped a hole in the adapter for it.
Here's how I routed the sensor cable up along the brake line with a few nylon ties
At first I used the brake line guide I had made up before, but it was a tight fit for both the brake line and sensor cable.
I didn't want the brake line to get hung up and kinked, so I made a new guide from a block of hard plastic I had. I put a 22 mm hole in it and made the base a little wider to better match the 58 mm fork upper.
Here's the drawing I made up for the new guide.
The new guide with the cable routed through it.