I often ride with just the right hand when I am on my old FZR600 sport bike when I am not at speed. This is done by slightly twisting and reaching with my right hand. At slower speeds it allows me to sit up a little straighter, which is easier on my back and wrists. When you are at speed and both hands on the bars, the wind supports your upper body. When not at speed, your wrists take most of your weight and riding with just the right hand, is just a much more comfortable riding position.