File this into the "things that everybody else probably already knew but I didn't" category... I was at my favorite local shop in Indy a couple of weeks ago bitching about how I couldn't get my chain tight enough when employee Shawn Wolf whipped off his shoe and yelled out, "shoe wedge!"
It works absolutely perfectly. Instead of using my own shoes, I usually sneak one that belongs to my wife because she tends to wear skids with a thicker sole than I do. Please don't tell her...!