Milwaukee packout mounts that can be attached to various things with screws. I've noticed that even in the worst layer line configuration, it's still very strong.
If we have all our bikes out, I use three attached to a piece of 2x4 and a bike hook to quickly stow my wife's bike (~34 lbs) out of the way instead of high on the ceiling hooks. I do keep her tire on the ground so she can easily retrieve it. That being said, I've hung my own bike (~28 lbs) with the wheel off the ground for a month without issue. I don't think I'd risk a carbon/fragile bike this way but it seems pretty stable for being 3d printed.
The author remixed this model.
Took JayC's remix of my model and just duplicated the holes for added stability/rigidity when attaching to things like 2x4's.