It took me years to think of this one, but when I finally came up with the idea I was happily impressed. I used to use three bungees, but my new system is half the weight, easier to use and a lot cleaner.

I tied 4 inch loops around the rack and then run a bungee through the ends of the loops. There isn't much tension on the bungee, so I'm not afraid of it snapping.

It holds my tent, sleeping bag, pad; all wrapped up in a 9' x 12' clear plastic sheet. The plastic sheet (painter's drop cloth) doubles as a tarp over my campsite at night. 4 ounces and needs to be replaced every 2000 miles or so.