Dear Carleton,
Recently noticed my rear tire was all weird and lumpy in 4 spots (2 on drive, 2 on on non). Took it to a shop as I was not in my home state and had no tools. When I installed that tire, a 28c, I used a 700c 28-32 Bontrager tube, which seemed to be too large in diameter for my wheels (it was folding as I installed it, but I thought it would fix itself as the tire inflated, I got the bead to sit). The guy at the bike shop assured me that I was an idiot when I told him this, and tried to sell me a new tire and tube. Lo and behold, when I take the tube out, there are 2 different spots where it was clear that the tube was folded onto itself (creases with talc collected in them).
What gives with these larger diameter tubes?