|A variety of social and physical impacts are attributed to mountain biking. In many cases, the perception of these impacts differs from the reality of on-site experiences. This distinction is explored in two ways. First, a brief review of impact issues associated with mountain bikes is carried out. Second, results are presented from a survey of 370 walkers on a multi-day natural track where biking has been allowed on a trial basis. Walker opinions are surprisingly positive toward bikes. These opinions are found to be more positive among those walkers who had actual encounters with bikes. By contrast, more negative opinions were found among those who had no such encounters. Such distinctions between perception of a conflict and the actual outcome from an experience have important implications for park managers responsible for providing a range of different recreation opportunities.