I bolted a 2X6 to the frame of my metal shop. At first I just had hooks coming straight out from the 2X6, but the bikes took up too much room sticking straight out. So, after seeing a swiveling bike rack advertised on social media, I looked them up. They were $100 each, so I passed. After thinking about t for a while, I bought 4 regular door hinges and attached them to 5" pieces of 2X4 then attached them to the 2X6. That worked OK, but I had troubles putting the bikes in the hooks because they kept turning on me. I went back to Home Depot and bought 4 screen door hasps with a hook and eyelet that I can hook and unhook to keep the hooks from moving. I like it. We'll see how long the 2X4's last, but they've been good for a few months. Total cost - $20.