If you want to get the most out of you motorcycle, or car, you really need to have a baseline measurement of your ride. A dyno is something that a high performance shop may have, or you can usually find them at a rally like Sturgis or Daytona. I have never seen one in a home shop.
Via hack a day - Make your own dyno
http://blog.makezine.com/archive/2008/05/diy_dyno.html