Let's not forget, (for those playing along at home) that the hot-point of the grouped treads should be placed at the center of the tire, rotated a short bit, then duped. It will wrap right around the tire that way, just like magic! ;) Check out Kix's gear tutorial for the step by step version. Same thing as adding the cog's to the gears. (Kix- I hope you don't mind my stepping on your toes a little... thought it could use a little clarification.)