well biked

Certainly the most noticeable place you can improve your situtation by tossing a cheap retainer is a headset, but I mentioned old cup and cone bottom brackets as well. Granted, unless you're doing a restoration, it makes more sense these days to simply replace an old bb like that with a cartridge unit. But since we're talking "theory" here, I do wonder what the real differences are in terms of performance and durability, with caged vs. loose balls, in something like an old cup and cone bottom bracket with one of the old "tin" cages. Or for that matter, what the differences would be if you used "tin" cages in a hub, vs. loose balls.

My experience has been that an old bottom bracket at least seems smoother with loose balls, and it also makes sense that the most important part of the unit, the cups, would last longer with the load spread out over more area as with loose balls. This is definitely the case with headsets, but again, I'm thinking it probably is still best to use loose balls vs. cages no matter where on the bike you're talking about, if the cages are the cheap tin type. Otherwise, why would any manufacturer have EVER used loose balls in hubs? Seems to me it would be cheaper to manufacture the hubs with caged balls, and if the performance is actually better with caged balls, there would be no reason whatsoever to EVER use loose balls. Again, I think it's likely that the key factor with these quality hubs (Campy, Dura-Ace) is the type of cages they're using-