It has crossed my mind to use my Birdy for light trails and off road. Aside from the gearing, could I throw some knobbies on there and use it for that purpose? I've seen off-road tires offered for the Birdy, but I can't seem to find a place that actually sells it as an accessory. Changing to the stiffer elastometer also seems like it would be a good idea as well. Any thoughts?