Mark Eaton wrote;
> I can't really determine objectively what
> happens to an aging steel frame, does the ride characteristic
> become softer and more noodle-like, or harsher and brittle?
> Is some rust a determining factor in its characteristics?
> Does anyone have the scoop on what to expect with old frames?
I think the agreement is 100% among the scientists that study these things, steel can't lose any "ride quality" over time, unless there are fatigue cracks, or a substantial amount of the original material is gone, rusted away like Jamie's Jewel. If all or most of the steel is still there and not cracked, then the ride is the same as new.
Many riders have claimed to feel a softening over the years, but I believe this is easily explained by psychological factors and the unreliability of human perception. I think if there were some attribute of metal that is lost over time or hard miles, that the metallurgists would have discovered it by now. You might say I take this on faith.