I have a really hard time fixing flats on one of my bikes, a Miyata 1000, because it's difficult to get the tires off and impossible to get them back on. I have three other bikes and don't have trouble removing or replacing the tires on those. And yes, the bead is pretty tight, but the tires are probably near two years old--it seems as though they should have worn out a bit by now. I've come to just accept paying a bike shop to fix flats on that bike (bike shop mechanics can fix them, although I have gotten comments about how tough it is to get the tires back on). But I'm planning some long rides out of the city in the next couple weeks, and I'm not sure what I would do if I ended up needed to fix a flat on the road.
To get to the catchy subject head: A couple years ago, I was told by a mechanic at one shop in the suburbs that sometimes, wheels will be made just slightly too large or small--not enough so that it would be noticeable to the eye, or that it wouldn't fit properly onto the bike. Just enough that getting tires on and off could be a huge pain in the ass, or that the tires would be a little loose and cause a bunch of pinch flats. I have chosen to believe this, because it makes me feel better about my inability to fix flats on this bike.
But, I wonder, could this really be the case? Has anyone heard of this phenomenon?