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So my rear wheel feels ever so slightly coarse compared to the front when I spin it in my hands holding the axle. I think I should replace the bearings but how do I go about it?

The hub is on a Mavic CXP22 rim and it has no markings. enter image description here

In online stores I can find some sealed bearings but basically none of the loose style bearing that this hub requires... why cant I find any?

Then there is the cones... are they usually replaced with bearings?

Finally I also wonder about replacing the bearing in freehub... if it's necessary? if it's even possible?

Or replacing the freehub entirely with a higher spec one, again if that's possible on this hub?

UPDATE: Looks like there is some pitting on one of the cups, also on the cones which will be difficult to source and likely expensive, for what they are. I replaced the bearings and will keep an eye out for cheap replacement wheel, functionally they are still fine and will be for a fair while before they become unusable I reckon. [enter image description here enter image description here

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    Before going too far down this route with this type of wheel, what condition is the rim in? If the rim braking has started to go concave, there's little point in messing with the hub. check it with a straight edge and post back.
    – Noise
    Commented Oct 7 at 20:26
  • The rim is dead flat
    – blofi
    Commented Oct 7 at 20:50
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    The only way to save that hub is to go back in time and grease the bearings annually from new. The rim is pretty cheap. Unless you want to build a wheel yourself with a new hub and spokes, buying a replacement wheel, used or new, will be the most effective option.
    – Noise
    Commented Oct 8 at 22:20
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    Basically overgrease this hub, and regrease it more often than normal. The spalled areas can't really be fixed in any useful way, though some claim products like JBWeld or similar metal epoxy can help, briefly, until it powders or otherwise falls out.
    – Criggie ♦
    Commented Oct 9 at 9:06
  • Thanks for the update. visible wear on the cups isn't great. I would look to replace the wheel over time. There are good deals on rim brake wheels out there, since they're not current tech. Since you're doing your own work, you can treat this as a learning opportunity.
    – Weiwen Ng
    Commented Oct 9 at 22:48

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Noise's comment aside, the loose bearings suggest a Shimano hub. You could simply take the bearings out of the hub, leaving the freehub body for now, and measure them with a pair of calipers. Then you count them, and you order them. One issue with this is the condition of the cups and the cones - those are the equivalents of the inner and outer races respectively in cartridge bearings. I think the cones tend to wear first. Anyway, you can drag a pen across the surface to feel for roughness.

Freehub bodies, even in Shimano hubs, tend to be cartridge bearings. In general, to replace cartridge bearings, you need to determine the type. It's likely written on the seal, or if you can't see that, measuring the depth, inside diameter (of the bore), and the outside diameter will enable you to identify them. For example, a 6806 bearing is 42mm OD, 30mm ID, and 7mm deep. However, it may not be convenient to remove the cartridge bearing from a freehub. I think that freehubs are generally just replaced. To do that, you need to know what hub model you're dealing with, and someone will have to identify the hub.

If you can find your bike's original specifications sheet, that could help. However, the ones for lower-end bikes may not be complete.

You can purchase a complete axle set with cones, something like: enter image description here These come in nutted and QR styles and are relatively cheap. Add new bearing balls and grease. You'll need cone spanners and patience.

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  • Am I right in thinking that excessive wear on cups might mean the entire hub would need to be replaced? Surely you would be able to go through numerous sets of bearings before this happens? The cones seem like fairly easily replaced parts, so I don't understand why they are an issue too?
    – blofi
    Commented Oct 7 at 20:57
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    The bike is a 2005 Trek 1000, I dont think is the original wheel though. The front wheel components are completely different The only information the manual for this bike gives on rear wheel is "Alloy, QR hub, 32°, Alex rim"
    – blofi
    Commented Oct 7 at 20:59
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    If we assume its a shimano hub, most likely rear bearings are 1/4" set of 9... I think those below are intended to be headset bearings but they are of the correct size and number... only good option I can see right now. I dont get it, why are wheel specific bearings so hard to find?? halfords.com/cycling/bike-parts/headsets-stems/…
    – blofi
    Commented Oct 7 at 21:57
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    Actually, you can definitely buy cones. But you need to know which model hub it is, and we do not. For the balls, perhaps someone should offer advice, but I don't believe any are bicycle specific. An ABEC 3 bearing should do.
    – Weiwen Ng
    Commented Oct 7 at 23:18

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