I have one of these Sportworks (now Thule) racks,
Somebody backed into it when it was on my car and bent both of the mounting brackets as well as the main "boom". The bicycle holders themselves are in great shape. The bracket that holds the bike mount on the very end was bent up so bad that I just pulled the whole bike mount off and have it by itself.
What do I need to put these 2 bike mounts on my factory roof rack? Does something exist or do I need to make something on my own?