That works except for the most dangerous encounter -- the one where you (the cyclist) doesn't know the dog is coming after you until it's within biting distance or nearly so. The silent, vicious attack dog that doesn't bark, but but comes running from behind the house and you hear its toenails on pavement from 12" behind your foot and closing fast. It was a nice ride, there was nothing to be afraid of. Why would you smell like fear? How would the dog smell it from 50' away?