RE: ***CUB BROTHERHOOD***
Cub man I have not had good luck with the O rings.. I found they broke even when not in use.. Also as you found I had to use different amounts of O rings for support. When I was purchasing my O rings I found you could get some that were a little heavier but it was the same story , they broke often and need to be replaced but when I switched over to shock cord all my troubles went away.. I use 1/8 " and you can play with the tension and wraps till you get the feel.. Yours will probably use about 6 wraps ,4 finger loops , maybe even 8 wraps .. Shock cord is cheap and you can buy it at some hardware stores or maybe a dress shop.. Its not too hard to find.. Look it up on the net.. I can find it in Canada but I am not sure about if you have Home depot stores in the States etc. ... Anyway give it a try...It will only cost a few bucks and I bet you will never look back..