This report is part of a continuing series of assessments of the impact of trail hikes in the area set aside for their use at Stromlo Forest. Details of the full assessment are given in a larger report which includes area description, methods, results, discussion, photographs and diagrams. This provided valuable opportunity to assess the impact of trail bikes on a specific forest area, both by immediate investigations and long term experiments. In Australia, assessments of this nature are apparently new. The scope of report implied more than a subjective analysis and some quantification was required. Techniques used were simple and further refinement may be justified.