The saddle bag I own has two elastic loops on the underside. From reading this question on long-term storage of tubes I can see tubes don't like changing temperatures (not really a problem in Ireland ...
The LBS's in my area tend to have major sales around the same time once or twice a year. During this time, I can get replacement tubes at about half their normal price. I can buy several tubes, enough ...
I got a spare inner tube with my bike, which is good. I checked how it was packed and found it was sticking somewhat when I pulled it out of the box, which I can only imagine is bad. Would it be ...