Powder Rocker, Piste Rocker, Speed Rocker..... What is "Rocker"? It's not a musician or a chair. The biggest technology change in recent years has been rocker. Rocker has changed how ski's and snowboard's work, making them easier to use and more versatile. But rocker can make things difficult to work out what size of ski or board you need, especially if you don't know what it is.