Yup, this is an old bike. I use it as my commuter, since no one will bother messing with it.
It's got a Sturmey Archer 3-spd hub on it and it's been riding fine up until a few weeks ago, when I noticed that the rea wheel had developed a really bad side-to-side wobble. As I ride it, the rear wheel shifts about 1-inch sideways with each revolution, always at one point, sort of like how a wheel would react if a bunch of spokes at one point were really out of tension.
I finally had a chance to look at it this past weekend.
I took the wheel off and the bolts were tight and secure. I spun the wheel in my hands and it spun smoothly and with no wobble at all; the wheel is perfectly round and true, even when back on the bike.
I re-attached the wheel and adjusted the shifting.
But the wobble is still there!
What could it be? It seems to only occur with a bit of speed. It happens while pedaling or coasting. It feels as if the wheel isn't bolted on at all. But since I know the wheel is on tight, I've continued to ride it like this.
I'd appreciate any tips you can give me. TIA.