Originally Posted by
CliffordK
Assuming a pair is being replaced, then the curvature may not be that important. It could be a problem if only one is replaced.
For stock steel QR axles, most fronts are 9mm, rears are 10mm. 9.5mm??? Bolt on axles may use non-metric sizes.
Anyway, measure the cones and buy the right ones.
If in doubt, try your bike shop as your first stop.
If you can identify your hubs, that can always help with the searches.
The races seem to be more durable than the cones, but you don't want to do anything that will damage your races, otherwise either the hub, or the whole wheel will need to be replaced... all because of a $5 part.
After getting some poor quality cones from major manufactures, I've started polishing all of my cones before installation. Just chuck them up on the lathe, and hit them with fine sandpaper for a couple of minutes. It works wonders. You could probably build a jig to do the same thing in a standard drill if you wish.
I've thought about restoring pitted cones on the lathe (cutting off a mm or so of length on each side and compensating with washers), but haven't tried it yet.
Sorry but I disagree with the highlighted statement. Cone curvature is in parallel with the cup's curvature. If the cone's curve changes too much then the balls will ride further out in the cups (which isn't real bad) or closer to the center (which could cause the balls to bind up on each other). Additionally if the balls shift their position far away from the center of the cup's curve then adjustment can get trickier. Andy.