I had to change a tube on the rear of the xchallenge and used a small Dasko Pro pry bar to break the bead. Basically pushed the bar between the tire and rim and pried until there was a workable gap, a few more bites working around the rim and the tire was ready to be spooned off the rim . No hammer, just a few bites, easy job. Here is a link to the home depot page, Sears carries them also. The bar is the middle one, great tool for many tasks, 9 1/2" long, little under 1/8" thick. $7 on the sears online page.