The cut in the top of the tube is actually an insert where a little bit of plastic within the joint fits into and is supposed to provide more support for the weight of the bike on the other side. Well, it's near useless and seeing as the joining clamp arm is only 2", eventually the weight of the bike is going to get the best of it.

I'm thinking some kind of L bracket that would connect to the stand pole and then hold up the clamp arm and support the weight of the bike more than the current structure. Just can't find anything. A shelf bracket is too linear; this would have to be something that could adjust.