Originally Posted by
verktyg
A rusty chain is ALWAYS a warning sign for me!!! I my experience bikes with exposed rust have always turned out to be more work than I anticipated: screws and nuts are rusted and either break off or the heads strip, EVERYTHING like cables, brake pads, bearings, tires and tubes will need to be replaced and so on. Chas.
I agree with Chas here. If a chain is that rusted then the bearing races elsewhere are suspect. Bearings themselves are not expensive and doing the clean/lube yourself is easy but paying some one to do it is expensive. However bearing races (cones, BB spindles and cups are expensive) are where the risk is. If the bearing surface on the hub is corroded then the hub (and probably the wheel) is scrap. Chas has pointed out before how thin the hardened surface is on these cones and cups are - cannot be sanded down to restore them. Scrap. Same concern with the headset bearings. A chain that rusted has been living outdoors so that same rain has been trying to seep into the other bearings and, if it has been successful you may have a lot of work to do.
The rusted chain is a warning flag that several other things could be FUBAR. Caution.