If I see a crown race in the condition below, a scoring all the way around (fork race is similar, but not as bad, cups are ok), my assumption is that it is not useable. However, this headset is sort of irreplaceable, at least not easily I think, so before I give up on it, wanted to check to see that my assumption is correct or if there is any hope at all...

Looks like you've just worn the plating off. No pits.
I'd say run with it.

Yeah, I don't see a problem with it. Headsets are pretty low tech anyway, it's not like they are spinning like a BB or hubs... I say it's fine.. rock it.

+1 Low tech application, not spinning like a bb or wheel hub. Go for it!!

You guys make me feel so good....

What scoring? All I see is worn plating. It should not have been plated there in the first place. I see nothing to worry about.

Who makes the headset that it is irreplaceable?

It's just a headset, man! Only Eddy would reject that one.

That's just worn through the plating, but keep in mind that plated headset races are generally a sign of lower quality parts. Instead of grinding, polishing, and hardening the races, they are simply polished and plated in the hope that the hard chrome will last long enough as a bearing surface. Once you've worn through the chrome, as you have with this unit, you can expect faster wear on the exposed soft steel beneath. There's no particular danger in running this headset, but when it wears to the point that it bothers you just replace it with something better.

A quick way to tell if is still good is to trace around the worn or scored track with a ballpoint pen. If the pen grabs or catches, the race is not in good shape. Then it is a personal choice whether or not to replace it.

I wonder what will happen with modern bikes when they need headset replacements in 10 or 20 years. A lot of proprietary stuff on today's bikes, and not just headsets.

Use it!

Oh, you'll just do what the manufacturers intend you to do - chuck it out and get a new one!

you might want to replace the balls with loose balls (no retainer cage) to increase contact area and "spread the joy", also consider Grade 200 carbon steel balls instead of Grade 25 chromium steel: softer against the now softer race, but more rust-prone so keep them greased.

They use cartridge bearings, most are the exact same cartridge, they will be widely available for a long time to come.

That's what I thought way back when, too.

I don't think this is a crown race, in that it doesn't look like it's designed for a fork crown. It looks (that straight cylindrical section toward the right in your photo) an upper fixed race, the one that gets pressed into the head tube. Plus, crown races and the fixed cups that mate with them often have divots and a lot more wear than the upper parts. I've seen this even in really high quality parts like early Campy Record and Shimano 600 wavy-nut - perfect uppers and trashed lowers.

The main wear I see is on the edge of the actual race (the actual race is the concave area), not in the middle where the balls should run. At that edge the color looks brassy. Is the base metal brass? If so I think this is a very low quality part, and it should be replaced if possible, with something that at least has ground and hardened races. I think many bearing cages are steel, rather than brass.

If you really don't want to replace it, I'd recommend going with loose balls rather than a caged bearing. I'm guessing that race edge wear is due to a bearing cage that didn't fit quite right. Loose balls will find the right place to run when the whole bearing is assembled and set. I like the idea of softer Grade 200 for this, unless someone who understands metallurgy speaks up.

The "brassy" looking material is copper, which is used as a base layer under chrome plating because chrome doesn't adhere well to steel. The middle part where the balls run is the underlying steel. The balls have worn through both the chrome and the copper and are now bearing directly on the steel.

I dunno, don't see it. What I usually see on my headset rebuilds is a distinct and narrow roughish track in the race area, where the balls progress one after the other. Maybe it's my monitor, but that's not what I see. If the chrome and copper layer are worn through, I'd expect to see a track, with a gray center, a copper border, and the chrome outside. I just see chrome all across the race.

The radius of the bearing ball has to be less than that of the race surface, to promote point contact of the ball, but there is to my eye no visible track. Could you be saying that the balls have kind of lapped their way completely into the race?

Sorry, it is the head tube race. FWIW, there were loose balls in it, and in person, it looks like it is worn through the chrome and then copper substrate.

You really don't see it? Let's try a close-up:

Ok, thanks, John, I was interpreting those lines as wear at the edge of the race, perhaps caused by the bearing cage, not ball wear.

Now I get it!!


Road Fan

Doesn't look that way to me. The balls should be running on the bottom, right-hand area that says "chrome". That area looks fine.

Maybe robatsu can take a good look and clarify it. I think it needs a fingernail scratched across it.

But the wear pattern clearly shows that they are *not* running in that area.