FWIW my set it is for two bikes. Have you check with 4x4 labs? I have seen a couple bike mounts on swing out by him.
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@LandCruiserPhil - Love your vertical mount idea using the front axle mounts. I did the same thing on the cage/rack on my Tacoma. I have a BJ73 now and would like to rig up some kind of axle mount that would work on the rear barn door. Any close up pix of your mounts, or ideas for me? Thanks