Hey, just wanna say that there is another way for clearing the 3rd rope. I dont know if its easier for you, but to me it was:
you can ride over the box so your back wheel hits the rope, then immediatly hit the brakes so your rider hangs completly over the box, only the back wheel on the box, looks like your going to fault, but you can recover from that by swinging forward and then back, while swinging back you should release the brake

you then will roll back and can go on.
also a little Ninja style but it worked pretty good on that box. I hope its clear what I mean? otherwise I will search for a video showing that.