This problem has been going since the spring. In the spring I dusted off my bike and got it out the shed, then I had a slow puncture and I mean slow it took about a week to go entirely flat. I lived with that for a few months pumping it up before setting off. Then I decided to get a new inner tube and broke two inner tubes whilst inflating it they just went pop! Eventually I managed to get one in and inflated but noticed there was a bulge around the valve but decided to go cycling anyway and sure enough on every revolution I felt a bump but the problem seemed to go away the further I cycled and I got home and put the bike away. And now 2 weeks later I have just got the bike out and seen the tyre is completely flat and has a fast puncture. I've been using continental conti tubes race 28 (700c) and have been checking the wheel for sharp or foreign objects when changing the tube. Is there something obvious I'm doing wrong here? I don't want to keep forking out money for new tubes all the time and its really beginning to take the fun out of cycling for me. Any advice please? Am I using the wrong inner tube it looks the right size.