I used 3/4 emt electrical conduit and 3/8 plywood for end caps and middle support. Emt is lightweight and cheap. Comes in 10ft. lengths. Drill holes in plywood to slide conduit though and secure with emt connector on each end. Space pipes far enough apart for tires not to fall though. Too close and your tires will bounce out going down the road. Every thing is availiable at Lowes or Home Depot.Need some ideas on a cheap way to make some tire racks. Thanks for the help
I was gonna post same then read your post, wooden blocks as ends and supports drilled for PVC, then drill PVC and place a bolt at ends to keep it from sliding out.