Which part of the system are you worried about? This is the Q and A answer to the velcro part of the system, which is a clarification of the rules that many teams have asked about.
http://www.firstinspires.org/robotic...need-answering
As long as your system doesn't extend outside of the frame perimeter, there's no reason that it can't move or extend inside the robot. Otherwise, this pulley system is just a ratcheting shaft connected to a motor. Very legal.