Do I need to replace the bearings?
 

My rear novatech track hub was having some grinding issues, so I removed the cartridge bearings to replace them, however only after I removed them did I notice the LBS gave me the wrong-sized cartridges. However, I was playing with the old bearings and they seemed to spin pretty smoothly in my hand. I cleaned out the bearing again and they seemed to spin like new. However when I reinstalled them into the hub, they had the same grinding issues again.

Is it the bearings that are the problem then? or is it the hub? I'm thinking maybe imprecise machining tolerances are maybe putting a lot of stress on the cartridge?

I'm going to try replacing them again tomorrow when I exchange the bearings for the right ones, but I'm worried I may get the same grinding anyways.

Just a note, that the hub were already grinding when I bought these wheels used 4 years ago. I just didn't get around to servicing them until now. The front hub spins smoothly.

IME, although the hub may be an issue, i have found that the "spin in the fingers test" is not very conclusive. i think that the discrepancy in forces between the fingers test and those in use are too great to warrant any definitive conclusion.

cartridge bearings are pretty inexpensive and sometimes can even be found at the local hardware store in lieu of the LBS, at an even greater savings.

i think i'd try a new set of cartridge bearings...

but there are really two alternatives i see off the top of my head. (1) replace the hub and all costs assiciated with doing that and accept the fact that you will never know what the real problem was. or (2) buy new bearings and risk having to do option one anyway.

i don't suppose the bearings in the front hub could be used in the rear hub to limit the risk of option 2 (which is the cost of the bearings) by any chance? you could then have your cake and eat it too. could you be so lucky or could it be so easy? :)

I would double check the right size bearings for your hub and replace bearings are fairly cheap. When you do this check to make sure there isn't a lot of wear on the hub or axel which isn't likely but you should always check.

Hi yes, I plan on replacing the bearings anyways, I can't get my money back anyways (no cash refund, only exchanges). I was just curious if anyone else has come across this before.

If the problem persists I can live with it. But as huey said, it is a matter of accepting the fact that I will never know what was wrong with it.

If this helps it is pretty common for cartridge bearings that are bad or going bad to grind under load with weight on them and still spin smoothely with no load or weight such asin your fingers or when you just spin the wheel off the ground.

This is why cartridge bearings blow chunks IMO.

For a multispeed rear, it's pretty hard to do better than a Shimano hub... tough as nails.

And the bearings in a decent loose ball hub last virtually forever when properly adjusted.

No one doubts the quality of Shimano hubs, and we all know that loose-ball hubs are as good as anything, if properly maintained and adjusted. But he OP doesn't have Shimano hubs. Are you the Shimano rep for the southern Hemisphere? I'd think so since every discussion that pops up about hubs, and if it ain't Shimano- there you are.
I too love Shimano hubs. But, they ain't the only answer. Cartridge bearing hubs have their place, and they do the job very well, when Shimano won't.

Ok Kimmo knows and likes Shimmano no big deal.

No, they're superior. That's my point.

Under a label saying 'half-arsed design'.

They're common as mud! With a bit of resourcefulness, you should be able to find one for free.

Sales rep is one of the last jobs I'd ever consider; I'm always advocating re-using old stuff, and discouraging the buying of crap.

110 please dont't

110 what now?

Just because one set of cartridge bearings is grinding after years of use doesn't mean that a new set of bearings is going to grind out of the box. They are two completely separate units. Replace them and don't worry about them.

Replace... and Replace again - No biggie... I have had this problem with brand new cartridges but worked it out by just replacing them with a brand new new set even of the same type...

And in the back of your mind is that old whisper that Loose Balls Rule...

Hi, so an update, I installed the new bearings, I think once they loosen up they'll be quite smooth. Frustratingly there is still a weird "bump" that happens once per revolution. I can feel it shift slightly in my hand when it is turning, like it is going over a bump or something. It is nothing serious, and I even think a this point I'm getting too anal for what is essentially my day-to-day beater bike. Hopefully It is something that will just go away on its own once I get some miles in on the new bearings.

Are you sure that the 'bump' isn't some amount of 'hop' in your wheel? Has it been trued properly?

How did you install the new bearings - did you 'drift' them in using the old bearings or a socket that matched the diameter of the metal part of the bearing race?

try a different tire, or at least find out where the hop is and remount the tire in a different position and check again. usually, if i try hard enough i can find a hop or two in my wheels, usually it's the tire. can a bad bearomg even CAUSE a hop? idk. http://www.cool-smileys.com/images/2070.gif

IMW (In My World :)), bearings grind and tires and/or rims are the source of hops.

I installed the cartridges using a socket piece that matched the outer diameter of the bearings.

And it's definitely not the rim or wheel, because I can only feel the "bump" when I hold the axle in my hand and spin the wheel. I can't feel it when the wheel is installed though. It is very minor anyways. I'll keep an eye on it and I won't worry too much unless it starts to get worse.

The 'hop' you feel in your hands when spinning it could be from the weight of the inner-tube valve going past on each revolution. ;)

First of all it's definitely the bearings, so replacement is necessary. However the problem may also be the (prior) owner. Radial contact bearings like these are not designed to tolerate side loads, and in this respect are very different from the angular contact design of basic bike cup/cone bearings. see sketch here

Many mechanics, home, and pro both are unaware of the difference and it's implications and adjust radial bearings with the same preload as they are used to using. That has the balls running on the edges of the track which rapidly disintegrates. These will run fine in your hand, but grind in the hub.

Keep this in mind when you install the new bearings, and adjust them to take out all bue the last vestige of axial play, do not preload them.

Thanks for this - I've just reassembled my Aksiums which are the only wheels I've owned with cartridge bearings in them, and I think I might have adjusted them with slight preload as I would do with all my other hubs which are cup and cone. Luckily I've not actually ridden on them, yet, since adjusting them. :)