hub repacking question

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bikefind
Participant
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Is there a way to determine, ahead of time, before opening up the hubs, what size ball bearings I have in my (2008) Specialized Rockhopper Comp Disc 29er?


Chris Mayhew
Participant
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You could try popping the dust shield off and having a peek inside.


Jason
Participant
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Rear: Should be 1/4″

Front: Should be 3/16″


dmtroyer
Participant
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What jason said. From what I understand this is very standard.

I’m not sure you can just pop off the dust shield and get any sense of the size of the bearing without compromising the adjustment of the cones.


Chris Mayhew
Participant
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Depending on the design you absolutely can. Often it just sits around the cone and lightly press fits into the hub. Sometimes the dust shield is integral to the cone.


bikefind
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Thanks!


Lyle
Participant
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They still make hubs with loose bearings?


BradQ
Participant
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Every Shimano hub has loose bearings… That’s a lot of hubs.


Jason
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If the hub is rough, chances are your cones and maybe even the races are trashed. You need to rebuild loos ball hubs before they get rough or you do more damage to the hub.


Lyle
Participant
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Cones can be replaced. Polishing the races seems theoretically possible but I imagine you’d just mess things up without a machine shop.


bikefind
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@jason: so as a preventative, what kind of a repacking schedule would you suggest for loose ball hubs that aren’t yet rough?


Jason
Participant
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Depending on your riding conditions, 6 months to a year. That is why cartrage bearings are nice, because you ride them till they develop play or get rough and replace them. With loose balls you need to change the grease when it gets dirty or you risk doing damage.

Yes, the cones are replaceable, if you can find them, usually they are all that is damaged and are inexpensive. If you let it go too long you can damage the races in the hub. If that happens you can try the old school tooth paste trick but more than likely you have done irrepaiable damage.


Lyle
Participant
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There’s a theory that oiling hubs instead of greasing them allows you to keep the bearings cleaner. Campy hubs used to have oil ports on them. Maybe they still do.


BradQ
Participant
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It’s not a keeping it cleaner thing, it’s a less resistance thing. Running hubs with oil rather than grease has lower rolling resistance, but gunks up and runs out through the seals pretty quickly. Fine for the track, but not so good out in the field.

Grease them with waterproof marine grease, buy it at the hardware store and save yourself some dough over the Park or Phil varieties out there.


Lyle
Participant
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Low rolling resistance is why campy does it, but running oil through to wash out the crud is why I bought em. Turned out to be more trouble than I cared for, so now I just use the hole like a grease fitting. Pump a little grease in with a syringe and wipe some crap off the axles. I once saw some hubs with little zerk fittings. I wanted them but lacked the cash. Now, I can’t find them. I suppose I could do it myself.


Jason
Participant
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Those were WTB hubs. The made some sweet pedals back in the day also.

I used to have a set of those high flange campy hubs and I used the hole as a grease port also.


Jason
Participant
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Grease guard hubs: http://www.icyclesusa.com/wtb-grease-guard-mountain-bike-hub-black-28h.htm

Look up grease guard pedals.


bikefind
Participant
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that was so much fun I want to do it again. By “very standard” do you* mean the 1/4 and 3/16 are likely to be right for most adult bikes? In particular I’m looking at doing a hybrid (giant farrago) that was made around 1996.

*dmtroyer, or anyone else with a sense of this

edited (again) to add: everything was in pretty good shape inside the new(er) bike, but I’m figuring there’s more chance I’ll find cones that need to be replaced in the hybrid’s hubs. Any advice on those? Is there also a typical standard for them, or specifications I can find somewhere? Or do I need to get my hands on them and see what they are?


BradQ
Participant
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Replacing the cones can be trickier, as the thread pitch from axle to axle can vary, as can the cone shapes themselves.

Kraynicks keeps a good stock of cones and replacement axles on hand and is the best place I’ve found to problem solve axle/cone issues.


bikefind
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makes sense. thanks Brad!


Lyle
Participant
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On a related note, anybody have a good source for cartridge bearings? I’ve got more play than I like in the front wheel of the tandem :(

And I don’t want to just swap one of my lightweight single wheels in its place.


John
Participant
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Any bike shop?


Jason
Participant
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X2, any decent shop will have a selection of bearings and if it is a weird size they will be able to get them for you. Probably will cost $10-15 for the pair.

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