I had to change the aerobars and need to reroute the cables and housing.

I got everything done except that i can't seem to figure out how to route the cable from the shiter to rd.

It comes down to bb but it is impossible to get it out of the other end on the chain stay from the bb. It almost seems like something is blocking it in the tube between the bb and chianstay. Is there a Ferrel\Magnet in there or something? Any tips would be great.