Wobbly hub
 

So I'm back from my first bike tour, but not without some problems on the way:

When in low gear, my freewheel broke. It was a relatively unused NOS Shimano freewheel (dunno model, but decent at worst). I don't know how to describe better than to say the freewheel body snapped. Luckily, I found a replacement.

After installing the replacement, I noticed that when coasting the wheel (upsidedown bike), the cassette seemed to wobble. Rather, it seemed to have a non circular orbit. There was no shaking a la loose hub. So, I figured that my axle was bent.

The axle was not bent. I learned this after comparing to a replacement, installing both, and still not having a change in behavior.

What gives?

My only working theory at this point is that the bearings in the hub are somehow just a little off in size, somehow allowing the axle to be slightly off in orientation when the hub is properly adjusted.

Other clues for solving the mystery:
- Adjusting the hub was not so easy. There seemed to be a friction point or catch point on each revolution, unless I traded for a slightly loose adjustment.
- I'm not using original cones - I did match the new ones to the old, and they seemed to have exactly the same shape
- I'm not using original bearings
- I've bent an axle on this hub as well, but I think that was when I pulled it out of the dropouts really cranking up a hill

Thoughts?

I expect the threads on your hub that the freewheel screws onto are damaged.

All freewheels wobble a little bit. But to be safe have your hub checked by a qualified expert...I assumed that should have been done when the freewheel was bought and installed on your hub unless you did it yourself. You may want to buy a better hub, sounds like you had a lot of problems with that one.

Hmm, that is not the case with my Campy Record on my Topolinos.

Do you freewheel or freehub (Cassette). All freewheels I've ever seen have a slight wobble up and down, not side to side.

It's a thread-on freewheel. The wobble is much more pronounced then I've seen elsewhere. It's also not just up/down. It seems like the axle is in crooked, wrt the freewheel.