I use velco straps for just the same reason. I don't see the need for a 'bag' per se.
Here's a pic of my setup. I used sticky-back velcro so the straps just stick on the frame. It works really well for me. Hope you find what works for you.
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Originally Posted by
KrisPistofferson
Did you just say "minarchist?" I'm going to start a 10-page vaginathon because only Libertarians can define Libertarianism. Also, you're mean.