Unfortunately my bike has to live outside, so I cover it. The cover I use is according to the packet, heavy duty vinyl with polyester lining. The question is, how long should I expect it to last? Had it about a year, and over this time it has developed a large sticky brown stain over the top, which I haven't been able to get off. I've just noticed that the stain is now hardening, with the result the outer layer is cracking & splitting, making it useless. Is this expected to happen, or do I just have a rather crappy cover? Dunno wat got on it, but I'm glad it's on the cover & not my bike!