Another option is to solder directly to the ribbon the cable. It saves you from having to buy the breakout board and allows you to connect two encoders per ribbon cable (you cut them in half in order to solder to them). A pin diagram for the ribbon cables can be found on page 5 of this document:
https://content.vexrobotics.com/vexp...User-Guide.pdf .
When soldering these I highly recommend using flux and be sure to individually insulate each wire with electrical tape or heat shrink.