If you are looking for a kit that works for Athlon and most others without bicycle inner tubes (lol that is pretty resourceful though)... google "Kapture Gear". I ordered the system in their pre-launch. I was in the first waive that shipped and they are shipping regular orders now. Pretty...
Google "Kapture Gear". It should come up at the top of the list. Down at the bottom of the home page is a link for a sizing chart. Download the sizing chart and see which ring fits. I know they have a kit for the the Gen2's but you will have to see what ring fits the gen 1's.