Never, even at low speeds (this applies for cyclists, too). But apparently the argument is that motorcycle riders will approach their riding with more caution.

Never, even at low speeds (this applies for cyclists, too). But apparently the argument is that motorcycle riders will approach their riding with more caution. To a certain degree, I will agree (when I wear less gear and no leathers, I ride with paranoia set to 80%, and assume the car behind me is going to drive with the intent of attaching me to the front bumper).