On centuries or long trail rides, we zip tie a spare tire to the seat post or frame. They are also great for attaching race numbers or maps to the handlebars. Of course, I'm married to a mechanic so we have HUNDREDS (in different lengths and colors)! With a few zip ties and a pocket knife, he could build you a new bike on the side of the trail.

If it's a temporary installation, ust don't cinch them down to tight or they are hard to cut off.