Friday morning I got my bike out of the shed and the front tyre was\nflat. No problem: I have spare tubes.\n\nI took the flat tube out and pumped it up to find the puncture -\-\- no\nsign of it. I went round the tyre, cleaning inside & out randomly.\n\nPut in spare #1 (used but patched): air goes out as fast as I can pump\nit.\n\nTried spare #2 (used but patched) outside the tyre first: also leaky,\nbut not as bad.\n\nTried spare #3 (unused, out of my pannier): good. Put in the tyre,\nwent to work with no spare tube in my pannier on the way, but fine;\nthe tyre even stayed up all day while I was at work. Put the unused\nspare out of my desk in the pannier, just to be safe, and stopped on\nthe way home for a pack of 3 spares, just to be safe for longer.\n\nGot home: the tube that had gone flat overnight was still mostly\ninflated (lying in the garden). I had to put it in water to find the\nleak, which I patched.\n\nTubes #1 and #2 both had several crackly-looking places parallel to\nthe moulding seam, so I discarded them. I'm sure they aren't more\nthan 3 years old, though -\-\- were they dud tubes or had I done\nsomething to encourage them to get like that?