The only complete leg amputations I've seen at home were from motorcycles being t-boned. The car bumper pinches the leg against the bike. In these cases a self-applied tourniquet would certainly make a lot of sense. Something else we tend to see with motorcycles is bilateral mid-shaft femur fractures from the legs impacting the handlebars after a head-on collision, although there isn't a whole lot of self-aid that you can do in these situations. I can't think of any motorcycle specific pieces of medical gear, you're looking at a lot of trauma caused by a relatively unprotected body impacting the environment.