RandomTroll

My front hub has 'races' (is that the right word?): a piece of metal
in which the bearings sit. On one side the outer half of the race
has detached from the inner part (but with completely clean edges:
it must have been made in 2 pieces). After I pack the bearings I
put the side with the attached race down, push the axle from the
bottom (cone attached for the bottom side), mount the top half of
the other race, then that side's cone. I notice that the attached
part of this race rotates on its own. I can't tell about the other
side.

Is this a problem?


What I usually call a race is a piece of metal that holds the
bearings, a toroid with an occlusion for each bearing. I think
that's just to make it easier to build, perhaps for machines.
That's not what I'm talking about.

FBinNY 

First some terminology

The bearing is the entire assembly that supports the axle and allows it to spin, consisting of the parts below:
The part you call the race is the retainer
What you call bearings are the balls
and the races are the tracks the balls run in, aka the cup and cone.

You don't need a retainer, simply pack the races with a full complement of balls (you'll need to buy a pack and use all new ones). The right number fills the cup leaving a gap of less than one ball width, usually 9 or 11. Coat the cup with a layer of gearing grease, and it (and gravity) will hold the balls in place while you assemble the cone, then invert and repeat.

bikeman715

If the cup (which you calling a race ) is broken then the hub need to be replace . By relacing an new hub to the wheel or replace the whole wheel all together . Or is it a dust cap that sit on the cone or the one press into the cup after the bearings are replace are you talking about ? if it the dust cap you talking about , then you might find a replace at your LBS in their used bin of parts .

FBinNY 

That's a good description of the retainer, not the cup nor cone.

fietsbob

A race track is where the race is .. bearings roll around in a circle that is their race.

RandomTroll

Quoth Wikipedia, 'The rolling-elements of a rolling-element bearing ride on races. The large race that goes into a bore is called the outer race, and the small race that the shaft rides in is called the inner race.' at Race (bearing) - Wikipedia, the free encyclopedia

I've used the same front hub for at least 10 years. Beginning 2011 April 5 I've repacked the bearings 5 times and adjusted the cones an additional 3 times. (I had no repairs or maintenance in the previous 7 years.) I don't know when I noticed the broken cup, but it was before my most recent repacking Saturday. It's a drag to replace a hub: I have to build a whole new wheel for one small broken part. I built a new rear wheel last month, and it works great - YAY! - but it takes me 4-5 hours. At least fronts are easier to build.

If the broken part doesn't rotate, or rotates with no more friction than the bearings (unlikely), then I don't think fixing it would make a difference. All the repairs over the last 3.5 years are consistent with broken-ness.

The bottom part of that cup rotates - is it supposed to? Or is this another aspect of its broken-ness?

FBinNY 

I posted based on YOUR description of the damaged part. Are you now saying that hat's not what you meant.

In order to help ypu more, I (we) need an accurate description of what kind of hub, and/or bearing (ie. cup and cone adjustable bearing, or cartridge bearing).

In any case, the hub race, or compete bearing IS replaceable, if you can find a comparable replacement.

Maybe this is the time for photos of the hub, and the opened bearing, and the broken part you described in the OP.

RandomTroll

I don't see how my follow-up is inconsistent with my original post. I have no camera.

The bearing balls are loose; there is no retaining ring. The outer race, the cup, on one side has come apart, the outer half from the inner half. The other side's race is still one piece; it doesn't move. Possibly the outer race is 2 parts, the outer part not attached to the inner part but to the hub. I've applied some force to the intact race and failed to get it to budge. I don't see how I can re-attach the outer part of the 'broken' outer race without a weld, which I won't bother trying and would probably fail at so delicate a weld. Would there be any reason a hub would be built the way mine is now? That is, is it possible the race isn't broken? The hub's problems could be worn races.

If I don't understand, I'd like to get enlightened. My history of repairs is consistent with hub failure; I've built wheels before; I just have to psyche myself up. Then again I'd be glad to fix instead: the rim and spokes are okay.

FBinNY 

Maybe it would help if you described the inner race. is it conical, or does it look like a ring with a groove around the outside? Also take a look at the two bearings pictured here

Does your bearing resemble an angular contact bearing or a radial bearing?

Traditional serviceable bicycle hub bearings (usually with threaded axles) are angular contact. If your bearing has a conical inner race, it's an angular contact. If so, odds are the cup is OK, and the part that's loose is a mating sort of mirrored part that's pressed into the shell after the cup to form an outer weather shield (or seal)

Here's a photo of a classic hub opened. You can see the damaged outer race or cup, and the seal ring outside of it. If that doesn't help, here's a link to a bunch of images. Find one that's descriptive of your hub, and click on it to isolate, then post a link to it, se we can all be on the same page.

RandomTroll

Mine is the 'classic'; it's inexpensive and at least 10 years old. It's sort-of sealed; there's a rubber gasket on the outside too. The broken piece could be part of an attempt at sealing. I guess it's more likely I've just worn out the surfaces of the races. (Of course I've changed the ball bearings.) I just need to get myself up to build another wheel.

AnkleWork

"Much ado about nothing."