You should really put a 2nd bearing below the first at least 6" away to build a moment connection. That single ball bearing wont hold up to much abuse and could become dangerous if somebody decided to hang off it or something equally dumb. I'm sure it's also not sized for much radial thrust. You can probably build a thrust washer that rides on the casting and not the inner race with a couple couple washers and a short chunk of PVC pipe or some other short standoff depending on what sorts of tools you have access too.