Originally Posted by Whiskeymike

I have a Thule Rack for carrying 4 road bikes and use an extender I got from harbor freight for $15 or so. Works great. The only thing I don't like is that there is a bit of a gap around the extender fitting into hitch. So there is a bit of play. I use a piece of rubber sheet to tighten it up.

The other thing to remember is that you need two hitch locks with the extender. Otherwise a thief can disconnect the whole thing. But they are cheap. Not sure if they make them where they can be keyed the same.