>>1909159>>1909159Here, have this from Sheldon Brown's site. It looks like shit, but who cares. I myself use two heavy duty, long, flat bottomed garage hooks screwed into my workbench right now. It works well enough, though depending on your bars it might be too tight. Downside is you have to lift the bike off and rotate it to get to the opposite side. I'm sure you could figure out a way to mount two hooks to something heavy, like maybe find an old, heavy wood piece of furniture to screw them to, and fill it with bricks if you can't build shit.
Mounted to my bench the hooks hold my 40 something pound 70s Raleigh Sports no problem. But honestly if you have any space with exposed beams, I would try the method in pic related.
Also, I found what are basically 3 foot long, thick foam covered twist ties at Ross, and I use those to secure the bike to the hooks if needed.