rear wheel wobble campag

[ColinJ]

Tap it out with a hammer!

 

[fossyant]

You may need the above. I'd recommend drilling a hole in some wood larger than the axel, and tapping the freehub off. It's likely a worn freehub bearing TBH. I've had play in both axel bearings and freehub bearings on my formula MTB through axel hub. Fixed with bearing change.

 

[antnee]

Thanks I've had the Axle out today and try as I might can't feel any play in the axle bearings but there is another bearing in the free hub which seems to be somewhat suspect. Thanks for the advice will look for some new bearing that are not too pricey!

 

[Graeme_FK]

Movement at the rim will not be related to loose or damaged cassette body bearings.
In the rear cassette hub, there are two, totally separate bearing systems (unlike Shimano, for instance).

1. The condition of the wheel bearing system decides play (or lack of it) at the rim. In some Khamsin versions (2015 onwards) this is adjustable.
2. The condition of the cassette body bearing system decides play (or lack of it) between the cassette body and the axle. This is not adjustable.

If you have play at the rim, this may be wear in the hub bearings.

The preload adjuster (the threaded collar with locking screw) that you have removed in order to withdraw the axle, is the method used to take up this wear.

The tighter the preload adjuster is done up, the further the "cone" inside the sealed cartridge bearings, is driven along the axle, so taking up the gradual wear that occurs in any bearing system. The fact that it's a cartridge bearing is irrelevant - all ball bearing systems work in basically the same fashion.

If you have used the full range of adjustment available on the preload collar but still have play at the rim, then the bearings are worn out and should be replaced. Normally in this circumstance, the bearings are also very "rough" as the wear that takes place usually affects some parts of the bearing surfaces more than others and if the wheels have been run loose for some period of time, this exacerbates the problem.

Beware that if you test the roughness of the bearings with the cassette body in place on the axle (i.e. with the hub fully assembled) any roughness that you feel may be in the wheel bearing system or may be in the cassette body, or both.

There are two ways to check which bearing system is responsible for the roughness, if it's only one of them.

The first is to withdraw the axle from the hub with the cassette body attached and spin the cassette body - if it is free and doesn't grate, then the chances are that the roughness is in the hub bearing.

The second is to leave the axle in place in the hub, to insert a 5mm allen key into the cassette end of the axle and use a 15mm spanner to undo the retaining nut that holds the cassette onto the axle. Note that this nut is LH threaded and has a spacer under it.

Fully undo the nut, remove the spacer and pull gently on the cassette body whilst turning it relative to the axle. with less than 1/3 of a turn, it will come free. You can then turn the axle in the hub and determine whether the roughness that you feel is in the hub bearings.

I'd generally recommend that hub or cassette bearing replacements are undertaken by a competent shop or individual with proper bearing extractors and a bearing press.

Bodge techniques, using a drift to "walk" bearings out and using a socket and a hammer to tap them back in, can irrepairably damage the hub shell and leave the user with a hub that is never quite right again. Sure, they can work, I've done it in the past "in extremis" when I've had to - but doing an efficient and reliable job with a lower risk of damage using the right tools is a lot easier and more likely to give a good end result.

 

[Graeme_FK]

Well having stripped the freehub and axle from the bike can now see that the play in the wheel is between the axle and the inner ring of the bearing so do I need to replace the axle though I would have that the bearing would wear out first? also can't see away of stripping freehub from axle to check other side. Though that side of the axle and bearing seem ok.

View attachment 652377

View attachment 652380

There is a tiny amount of clearance, between axle and inner ring of the bearing (else you wouldn't be able to get the axle through) - so it is a light push fit. The fit is good enough that rotation of the axle will carry the inner ring of the bearing around with it, provided there is not too much resistance (generated by wear or corrosion, say) in the bearing.

You may be seeing movement between the inner ring of the bearing (like the "cone" in a traditional open bearing) and the outer (like the "cup" in a trad bearing). This movement is normal even in a new bearing (though in a new bearing it is typically very, very small) and is taken up by the preload adjuster.

As noted in my other post, once the preload adjuster can't compensate for that movement, generated by wear on the bearing surfaces, the bearings are fully worn and should be replaced.

 

[antnee]

Thanks for the above advice Having enlisted the help of my brother i law (a former tool fitter and maintenance fitter he got the wheel bearings out in a jiffy plus making up a bearing extractor and press for the freehub We found that the drive side rear wheel bearing far more worn than the the other side, both the front wheel bearings are slightly worn so It surely good practice to replace all. Plus one of the free hub bearings is worn too so until I get some decent replacement the carbon bike is of the road, though am assured that it is the work of half an hour to fit the new bearings, Can you recommend a good brand of bearing SKF or Timken perhaps? Oh that won't cost the earth

 

[Graeme_FK]

Bearings for Campagnolo are (mostly) made by FAG as their bearing partner.

I'd recommend any "name" bearing (FAG, SKF, Timken, EZO, etc) - but buy them from a supplier that you know to have a good relationship with a recognised (i.e. official) importer / distributor, rather than the cheapest source.

I've seen a lot of beraings out there from very cheap sources, ostensibly from a named maker, that don't measure accurately. I don't know if they are dimensional tolerance seconds, or just plain counterfeit. Having installed a few over the years (to my cost) I have learned that lesson the hard way and work with a local bearing factor now, that I know and trust.

 

[antnee]

Thanks Graeme, I must say I don't know anybody around here that supplies bearings but I can enquire at my local suppler of all things taps dies and nuts and bolts would think that they will know someone. if not themselves as never enquired about this area of their market Thanks for all the sound knowledge . I might mention that the ones fitted are S&S as the picture of rear wheel bearing shows.

 

[antnee]

Found there is a circlip in the free hub body which you have to remove before being able to remove sealed bearing nearer to the ratchet cams bit awkward to get at still its out now

 

[antnee]

Fitted new bearings to Front and rear wheel plus the freehub, all working ok quick test this morning. Though Must get a better pair of inside circlip pliers! Thanks all for help with this.