Originally Posted by
sbarner
Repacking bearings is necessary as the oil will have migrated out of the original grease and the bearing may have become contaminated in use. The downside is that it can be tough to find replacement parts that are in better shape than the ones you have, should you find damage. My approach is to clean the balls with solvent and inspect the rag. If I don't see any tiny flecks of chrome, and the races are not pitted, I re-use them, taking care to keep sets together with the others that came out of the same side of the bearing. Modern cable housing is lined and thus performs much better than the originals, which usually have kinks in them, anyway. If the inner wires have no oxidation (they were typically made of galvanized steel wire strands, twisted together), are not kinked, and the ends have not been damaged, it is not necessary to change them. Modern cables are not very expensive, and the stainless steel ones that have been drawn through a die, a.k.a. "slick", will outperform the originals, but it might be difficult to find shift cables with heads small enough to fit your Simplex shifters. If filing down the head is required, know that it is a tedious task to reduce the head diameter by even small amounts. Test it by sliding the cable head into its socket backwards until it slides easily into place. If you force the cable head into the lever at all, you may easily find that you can never get it out again without wrecking the lever.
Please do not "clean the balls with solvent." There's little to no reason to re-use old ball bearings. Most bicycles come with low-grade (300) ball bearings. Standard overhaul procedure is to replace used balls with brand new, higher grade 25 or 20 ball bearings. This will ensure smoother and longer bearing life & operation. Additionally, you'll find that you can improve bearing durability by tossing the bearing retainer and going with MORE free ball bearings. Bearing retainers are used by manufacturers as a cost-saving measure. To put things together MUCH faster. The typical bottom bracket's 9 1/4" ball bearings in a retainer can be replaced by 11 free ball bearings. That's over 20% more ball bearings, distributing load among more ball bearings, race and cone surface area.
In headsets, the difference is even more impressive. I'm overhauling a 1984 Univega. Headset ball bearing retainer holds 16 ball bearings. Tossing the retainer means I can use 24 ball bearings per headset cup. That's 50% more bearings! And higher grade means they'll operate more smoothly. (Just be sure to not "pack" in as many bearings as you can fit in a headset. It's general procedure to remove one for "open space" in a headset.)
Plus, cleaning bearing retainers is a PIA.
Why do it when it's more time-consuming, lower quality, less durable and not as smooth?
Edit to the OP:
Oh and the rebuild is looking great! Nice job. I hope you enjoy it. BTW, having a Reynolds 531 fork is an asset; I assume it is indeed original.