rain
An archaic definition of atone is to be reconciled or at harmony with something. At on, in harmony, at the point or moment of being on. That's it. That's part of the motorcycle experience. To be atone with the weather. On a cycle one is in the weather rather than traveling through the weather. There is a connection with nature, and by extension with God, that does not exist when one is an observer in a climate controlled environment going through, but not in, weather. Perhaps that feeling of being atone with a facet of God is central to the motorcycle experience.
Over the centuries humans have gone to great lengths to experience that feeling of being at on. When in harmony sometimes it is harmony with and sometimes it is harmony within. Being at harmony with, with nature and the machine, yet not being at harmony within is incomplete. There is still internal discord. Sometimes driving a motorcycle, achieving that harmony with helps achieve harmony within. It helps send the demons of dis-harmonic thought away.
Sometimes that same harmony is established by walking, or sitting in the woods, yet it is difficult to hold the feeling. That clarity of thought and sense of peace tends to last easily when driving a motorcycle. It is a bit like being able to compartmentalize the mind, to focus on the calm part and let the remainder be occupied with driving, watching for gravel, attending to the many small motions that keep the physical balance and free the other part of the mind. It is the mental equivalent of send the children out to play so one can relax and concentrate on some important mental business. It is a precious time of being at on, exactly and wonderfully on.