Dirt bikes are a wonderful recreation but noise concerns remain a problem...
I appreciate the pleasure people get from riding their motorbikes in natural areas and if the bikes could be created to run reasonably quietly then they would be a welcome addition to many natural areas designed for general human recreation. But as the bikes are at the moment- with their extreme noise levels- they don't belong in quiet natural areas but instead in the noisy cities or on a race track.
When ridden without due care, dirt bikes violently upset the peace and tranquility of natural areas and are offensive to other park users and the creatures that live there. However, by riding considerably, by limiting revs and not spending too long in the one area (i.e. by passing through areas rather than doing laps), for example, then some kind of accommodation can be reached!