I'm very confused...I took my bike over to Harris Cyclery yesterday to have a couple things looked at, ask a bit of advice, and pick up a new shifter cable. I had experienced problems with excessive friction and related noises (squeaking and clanking) coming from the front wheel, and the guy I spoke to told me that my axle cones were overtightened. I don't have cone wrenches, so he adjusted it for me, and it was working fine for the whole rest of the day yesterday (8-9 miles' worth of riding), and then for another mile and a half or so today...but then suddenly, the friction and noise reappeared.
The wheel spins mostly freely in reverse, but then when you go spin it forward, it stops quickly.
If it matters, it's an early '70s Columbia Sports III 3-speed that I understand to be home-built to some degree, by a relative of the Craigslist seller I bought it from. The wheels look to be all original, or at least from the same time period.