dedhed

Go to the local bearing supplier, tell them grade 25 and what sizes. You can usually buy them in packages of around 100 depending on size.

https://www.superpages.com/yellowpage...CA/T-San+Jose/

Flippers if they look good reuse, keepers get them replaced.

HillRider

Yes and no.

Yes, the headset is the worst abuser of bearings due to the impacts they absorb and the fact that the angular displacement is so small under normal riding conditions that the lube isn't redistributed very often.

No, the bearing don't "ovalize" and if they are still clean and rust free can be reused. What eventually kills loose bearing headsets is "Brinelling" of the crown race and lower cup race, i.e. little dents or pockets that develop from impact and fretting where the balls touch the race. This produces "index steering" when the balls stick in the pockets. A temporary fix if the original bearing balls were in a retainer is to discard the retainer and add an extra ball or two to the race so the pock marks and balls no longer align.

well biked

Regarding headsets, I'm amazed at how quickly the bearings can become "indexed" on cheap headsets. The headset is one area a bike manufacturer will sometimes skimp to save money, and even on decent new bikes you'll sometimes see pretty much the crappiest headsets available. I've seen "indexing" on these in as little as a few hundred miles, maybe less. To put this in perspective, the original tires on the bike might last two to three times as long as the original headset! To clarify, these are not cartridge bearing headsets, but have caged bearing balls and are apparently the cheapest quality races, balls, etc. that money can buy.

Bikewer

Way back when I started working on my own bikes (70s) I got a copy of the repair manual put out by Bicycling magazine. They said flatly not to re-use bearings...
All the local bike shops here have 'em, I just buy them as needed. I count the ones I take out of the hub or whatever and take a couple in to the shop so they can run 'em through the bearing sizer (just a gauge) to make sure of the size.
Another source is the big industrial supplier, McMaster-Carr:https://www.mcmaster.com/#steel/=bp9obt

HillRider

My experience too. I had a Trek 1420 that came with a low-line Tange headset which developed index steering in under 4000 miles despite good maintenance. I replaced it with a Shimano Ultegra 6200 headset (still a loose bearing design) that lasted well over 15,000 miles.

Actually the best 1" threaded headset ever made (except for the $$$$ Chris King) was the Shimano Ultegra 6400 cartridge bearing version. These were reasonably priced, easy to adjust and lasted nearly forever.

electrik

The phenomenon is actually called false brinelling since the mechanism which causes the fretting is different.

HillRider

You are right but this is a thread on bearing replacement, not a detailed mechanistic discussion on arcane metalurgical definitions. I used the term "Brinelling" in quotes because, while it isn't technically accurate, most readers know what it implies.

wrk101

Even on flippers, I always replace the bearings. Buy in bulk, and they only cost about 2 cents each. What is your time worth? Is saving 44 cents on a bottom bracket by reusing ball bearings meaningful? Without a microscope, I don't trust my inspection. I save money elsewhere (bulk housings and cables, etc.)