Knowing motorcycle speeds at various points throughout an accident sequence is valuable in reconstructing an accident. Often, the motorcycle slides on its side for some distance during the accident sequence. In order to account for the sliding segment in the speed calculations, a suitable slide coefficient must be selected or determined. During this study, an accurate measurement methodology was developed for determining slide coefficients. Once the test methodology was established, eight different motorcycles were tested to determine their slide coefficients at 48 and 97 km/h. The test surfaces were asphalt pavement, dirt, and gravel, and the motorcycles were tested on the right and left sides. Some motorcycles were tested multiple times on one side also. The test group included standard, cruiser, sport, and touring motorcycles.