All of these issues continue to require research and dialogue. Most land managers are charged first with protecting the resource and the primary question regarding mountain bike use was what are its impacts. Both of these uses tend to have fewer impacts than do equestrians. The second concern has been one of safety. Bike advocates would point out that while there is the potential danger inherent in all outdoor recreation, the number of mountain bike fatalities and serious accidents is minuscule given the number of riders.
Accidents involving bicyclists and other users are rare.
Closely related is the question of liability for both public and private land managers. Bike advocates like rock climbers and other backcountry recreationalists urge cyclists to take personal responsibility for themselves and their equipment. IMBA distributes a booklet of recreational trail liability laws in all 50 states to reassure public and private land managers. Finally, there is the question of aesthetic or philosophical appropriateness. The bike is a machine.