For the last month or so, my main bicycle has had a wobble in the rear wheel. I've been busy with other things, so it wasn't until last weekend that I got the bike up on the stand to true the wheel.
After getting the wheel off the bike, I started checking the spokes to see if any were broken before putting the wheel on the truing stand. Unfortunately, I had a broken spoke. That explained why the wheel was so out of true. What it didn't explain is why I had several prominent cracks and holes in the rim. I bought that set of rims five years ago while we were still living in Alameda, CA. Over the next five years I put several thousand miles on those rims. I rode that bike in the rain, in the cold, in the blistering sun, on gravel, on limestone, and on pavement.
What I had done, essentially, was wear those rims out. The rims weren't double-walled and they were the cheapest aluminum alloy rims that I could get at the time.
The manufacturer most likely didn't anticipate that anyone would buy those rims and then put several thousand miles on them in short order. Between the stress and strain of hitting bumps in the road; being worn down by the brake pads and road grit; and carrying myself (185 pounds) and sometimes up to fifty pounds of gear those rims suffered through quite a bit.
Now, however, they can go to that great aluminum scrap heap in the sky. I just got a new wheel custom built for me by one of the local bike stores. It's a Surly track hub (read: bolt on and designed to be used with a single-speed freewheel) that is connected to a Velocity Deep-V rim (read: double-walled aluminum alloy; known in the MTB community to be rock solid). Combined with my usual tire (Panaracer Pasela Tourguard), it all makes one really nice wheel. The bike shop even threw in a new freewheel for nothing.
For the last week, I'd been riding my Miyata frame which I also got in California. That's a nice bike, don't get me wrong, but for around town riding, I'll take my beat-up old Schwinn. The Miyata is a zephyr meant for long, speedy road rides; the Schwinn is a beast of a bike with its single-speed freewheel, collapsible metal panniers, and a trunk. All of that is attached to an old-school steel frame. While the Miyata also has a steel frame, but it is stiffer and lighter which gives a much different road feel.
I took the new wheel out for a ride today and it is fabulous; it's worth every penny that I paid for it.