An ice cycle, ice bike, or icycle is a bicycle adapted for use on ice, usually by replacing the front wheel with an ice skate. [1] [2] [3] [4] [5] Versions exist with and without additional skates to provide lateral stability, [1] [2] that have been based on upright and recumbent bikes, [6] and that have been used for racing. [3] [6] Ice cycles have been in use since at least the 1890s, [7] and theory predicts that a bicycle with a front skate can exhibit riderless self-stability similar to the same bicycle with a front wheel. [8] At least one example has been made with both the front and the rear wheels replaced by skates. [9]