I am looking for a good fitting tank bag for my 1100RS,non-magnetic since tank is non metal.Been looking at all the different web sites and a clear winner did not appear.Looking for something not too big,easy on/off,durable that will not ruin the tank.Need it mostly for day-trips.I do not know if all have a base that stays attached to the tank when bag is off the bike.What are the favorite bags used by this group and why?Thanks for all input,Karsten in Mobile