Campy Record freehub bearing replacement ?

[jamesld8]

Despite being just 2000 miles use my rear Camapg Record hub feels rough running, bearings feel gratey. Dismantled hub today and found that the actual hub bearings are silky smooth and issue is the freehub bearings (sealed cartridges) are source of the grateiness.

Does it matter too much, given that actual hub bearings are smooth? And if it does what size cartridge bearings , and how to, replace those in freehub unit?

ta

[Torslanda]

Surprised you can actually hear anything over the noise of the freewheel! 

Ackcherly . . . If the bearings feel 'rough' but don't exhibit any sideways play they will probably grumble on for a while yet. If the cassette is wobbling then it's time to replace the bearings.

Likely - but not guaranteed - that both the bearings in the freehub are the same. Initially look for the part number on the bearing seal (e.g. 6002 RS) then enter that into a google search.

[zigzag]

the way the hub and freehub are designed it's bound to wear out quickly. no extra protection from water ingress, so any wet ride can further reduce the mileage. there are two 6803 cartridge bearings in the freehub, that spin all the time whenever the wheel is spinning and give a rumbling sound if they are worn out.
they can be easily replaced as the all other sealed bearings, by punching them out and pressing the new ones in. there is a free floating spacer between the two freehub bearings which can be moved to drive the first (outer) bearing out. are both bearings worn out? repacking bearings and the void between the spacer and freehub body with grease is a good idea.

[Ian H]

I've found it's the inner bearing that goes.  As Zigzag says, quite simple to replace.  I tend to prise off the inner seal, add my favourite grease, then replace seal and fit bearing.

[jamesld8]

Thanks for useful replies, I`d have to check which has gone rough by removing freehub unit again. There`s no wobble yet on cassette so maybe some life left in them before I fit new cartridge units--any recommendations for which type, eg Enduro bearings , better seals ?

[Ian H]

There are no better seals.  Go for FAG or similar good quality from your local industrial bearing supplier. 

[Brucey]

there are very many levels of seal quality available.  The enduro ones are good quality but you do pay for them.

FWIW if you buy standard '2RS' industrial bearings of reputable make (eg SKF)  you will get something that is reasonable quality and the seals ought to be better than those you get on cheaper 2RS bearings (which are often not full contact seals even when new, if you look at them carefully). However unless it is a special bearing variant, the grease fill (by type and volume) will be suitable for life at 10-15000 rpm, which means it is a long way from being optimised for use on a bicycle. SKF etc do versions of their bearings with an increased grease fill for lower speed applications (comparable to bicycle speeds), but the grease still isn't ideal for bicycle use. [Such bearing variants won't be stocked by most suppliers and may have to be ordered in at greater cost.]  The enduro ones have more, better grease in than that, and better seals (for bicycle use).

Cartridge bearings are normally also specified for fit tolerances; someone with a super-accurate micrometer may be able to tell you if the old bearings had an unusual fit tolerance on them or not.  When you buy an 'off the shelf' bearing, you are probably getting a middling tolerance of some kind, which may or may not be ideal for your application.

In the campag 'freewheel body' (strictly speaking it isn't a 'freehub', some say)  the inboard bearing is usually retained with a circlip. The procedure is usually to nudge the spacer to one side, bosh out the outboard bearing (outwards), remove the spacer, remove the circlip, then (and only then) bosh out the inboard bearing (again outwards).

In the short run I'd suggest nudging the spacer to one side, and filling the void with gear oil. This may keep the bearings happy for a fair while longer.

In the longer term when installing new bearings, I recommend removing one seal from each bearing (on the side that faces the other bearing) and packing a load of semi-fluid grease between the bearings. IME, even bearings with dodgy tolerances and iffy seals will last a long time like this.

cheers