wheel bearings

[mimitabby]

Mimi, please let us know if the bearings are sealed or not. If they are sealed, they will eventually go bad and the bearing cartridge will need to be replaced. But a cartridge should be good for at least several years. If they are not sealed, ie. you have servicable bearings, then they need to be repacked at least annually with new grease. Servicable bearings also need to be adjusted so that the cones, bearings, and cups fit together with the optimal clearance - too tight and the bearings don't roll freely, too loose and the rim can wobble side to side causing poor performance and hub wear. Riding on a loose hub would also permit more water entry and contamination and allow the grease to be washed out. So perhaps your front cones were loose and your rear ones properly adjusted. If you do have servicable hubs on this bike and neither have been serviced in over a year, you might want to ask the mechanic to repack both hubs just because. When he said the rear one was OK, did he mean is was as smooth as if it has just been repacked and adjusted, or not binding and not loose and not horribly gritty? Different mechanics could have different standards here, and different standards for their own bike vs someone else's. Or he could want to save you money and only do them if they are really bad vs giving you optimal performance and maximum hub life.

If you really care about your bike, you should be making the decision on when to service your bearings and keeping track of their condition. You should be feeling your hubs periodically - once a month would be about right to see that they are in proper adjustment and adequately greased. When you get your bike back, Mimi, you can assume that your hubs are well greased and adjusted. So get used to what they feel like at that point and monitor for changes in the future. Here are some ways to check out your hubs:

1) with the wheel on the bike, grab the rim and try to move it side-to-side relative to the frame. Do this at 2 or 3 places along the rim. Any movement at all means the cones are too loose and should be adjusted before you ride the bike again.

2) hold the wheel off the ground and give it a spin. It should spin for quite a long time before slowing down very much. This is somewhat subjective, but if you do this often you should notice a difference when the grease gets old or contaminated or washed out.

3) take the wheel off the bike and turn the axle/cone between your thumb and index finger. It should feel very smooth and non-binding. If it feels gritty or doesn't turn freely or has a "washed out" feeling, it needs service.

4) you can also hear your bearings by putting your ear against the rim and turning the axle (don't know if this works with fancy fiber spokes, but steel spokes will transmit sound and vibration to the rim). Try it if you like, but not sure if this is something you can teach someone over the internet.

Deb, it's my Bianchi, they are definitely serviceable bearings. !
thanks! (again the problem was definition and ignorance on my part)
he will probably rebuild them if the bearings need replaced. While i was there the (young) mechanic did all of these things that you suggested (except the ear against the rim) and that's why he decided that only the front one needed work.

That's why i was asking, why would the front one need work but not the back one? they've both been rolling the same amount of time!

From your answer, I can see that i need to call him this morning and tell him i want them both repacked, not just the front, THANKS!

[Grog]

Deb: so what does this mean for non-serviceable, scealed hubs? If they were built okay to begin with, they'll be fine for ever? Never need to be reopened?

[mimitabby]

let me hazard this one.
It means when they wear out you have to buy new ones.

That's one of the beauties of campy components, they are rebuildable. When one small part wears out, you don't have to throw the thing away.

[DebW]

Deb: so what does this mean for non-serviceable, scealed hubs? If they were built okay to begin with, they'll be fine for ever? Never need to be reopened?

They won't be fine forever. But when they go bad, instead of removing the ball bearings and adding fresh grease, you remove a bearing cartridge and replace it. Bad bearing cartridges feel really bad.

[Grog]

They won't be fine forever. But when they go bad, instead of removing the ball bearings and adding fresh grease, you remove a bearing cartridge and replace it. Bad bearing cartridges feel really bad.

So what would be the expected lifespan of a bearing cartridge?

[DebW]

So what would be the expected lifespan of a bearing cartridge?

I don't have alot of experience with them, but I think they should last several years, maybe 3-5 years or more. Maybe others have some direct experience.

[Grog]

I don't have alot of experience with them, but I think they should last several years, maybe 3-5 years or more. Maybe others have some direct experience.

Thanks Deb for the precious info.

Mine are a cause of no problem so I'll leave it at that!

[DebW]

I do have a set of cheap Performance sealed bearing hubs. They've been used mostly for commuting off and on over the last 15 years and they still feel super smooth. 3-5 years is probably a low estimate even for someone who puts lots of miles on their wheels. The good thing about the cartridges is that when they go bad, they won't damage any other part of the hub. If you ignore a servicable hub long enough for the bearings to get pitted, it will pit the bearing surface of the hub body, and then the whole hub needs to be replaced.