Hi everyone,

I have a Raleigh Technium 450 with 27 inch wheels and tires. Recently, I have had problems with numerous flat rear tires, the most recent of which was a blowout while I was riding. I ordered two new tubes and as soon as I inflated them to about 80 psi (tires are rated to 90 psi) they popped within a minute or two, just sitting by the pump. I can't find anything sharp on the rim or on the tire, my rim tape is new, and I checked carefully to make sure my tube was seated properly. Also, the holes are all on the inside edge of the tubes. The tubes themselves were 700c by 28-32, although they did seem a bit small as I was putting them on. My rim is just a little bit bent in a few places (the edges are a little flat since the bike was stored for a long time with no tire)-- could that be the problem? I'm at a total loss!

EDIT: Problem resolved! (I posted below, also.) Turns out I had a small hole in my tire and the tube was bulging out of it. I've replaced the tire and all is well. Thanks again to everyone for all of the good advice!