OndrejP_SK

Hello,

a few years ago when Deore LX was ending as mountain group, I bought 2 rear hubs because the price was good and a good rear hub in parts box is not bad.
One I laced to a wheel, and it has already more than 5k km and is generally OK.

The other one I laced just recently, but I noticed it feels like something is wrong with it. English is not my native language so I'm not sure how to describe it, but this quite often happens to headset, when it is worn it has this position where the balls jump into small dimples in the bearing races created as result of thousands of bumps on the road. Except that this hub has not been used at all !

I opened it up and there are indeed small dimples in both the LH cone and unfortunately also in the cup

How do you think it happened ? Was it just too tightly assembled from factory ? But I remember it felt OK when I bought it.
I remember reading somewhere that there can be some chemical effects between metals pressed tightly with each other even with grease present - I'm not really sure this could have happened here.


I'd also like to ask the more knowledgeable folks here what should I do ?

Should I replace the cone and balls (hoping that the cup will wear in), or try to ride it with the notched cup and cone (hoping both cup and cone will wear in) ?

When I reassemble it, should I tighten it more or less than usual ? (I think more = to make the balls create a groove in the cup and cone, and to make it smooth again)

fietsbob

(sight unseen Guess) Pitted cones means it was not NOS it is Used.

CliffordK

Perhaps rust or oxidation spots. If superficial, they might be able to be polished off of the races using a wire brush in a drill.

Cones can be replaced, or again with superficial damage, perhaps polished by spinning in a lathe or drill, and sanding the surface 400 then 600 or 1000 grit.

OndrejP_SK

fietsbob: The hubs were new, bought from german eshop few years ago. Not used, not laced.

fietsbob

I cannot see what you call 'dimples" take it to someone who can see what you are talking about, first hand. in Person.

Certainly the largest city in Slovakia has a Bike Shop.

CliffordK

Or a high-resolution digital camera.

AlexCyclistRoch

Sounds like somebody "brinnelled" it by screwing the cones in so hard that the bearings ruined the races. The hubs are scrap. If you'd just turned them when you bought them, it would've been obvious.

OndrejP_SK

Alex: I definitely did turn it, but I don't remember it feeling like it had this "indexed" positions. But I'm not sure now. However your explanation seems most likely

fietsbob: imagine a brand new cone, shiny, with 9 little flat spots where the balls have been "impressed" into the surface. The same in the cup. I will try to take a photo.

Sure there are bike shops but none that would know what to do in this situation. They would just advise to buy a new overpriced hub.

Now the question is, if I want to try to ride it, how should I set up the bearings...

Slash5

I'd guess that it was dropped on the left hand side at some time and the impact dimpled the cone and cup. I think I'd find a replacement and consider this one for spare parts.

sch

What is the planned use for the wheel? My opinion: replace the cones, lace up the wheel and ride it. On typical pave, gravel, dirt you will never ever
notice the dimples. You want to 'wear in the bearing races"? You could accelerate by using some medium lapping compound mixed in with the grease
(eg: Clover lapping compounds and grinding compound, clover brand, clover, fel-pro, felpro, loctite lapping compounds, lapping paste) for 5-20 km of riding then dissassemble and examine the hubs and if ok clean assiduously and regrease
with good grease and ride on. Or repeat until you like the way they look. Seems excessive to discard the hubs just for dimples considering the minimal
effects on riding the bike the dimples will have. This differs a lot from brinnelled headset where only limited range of motion is present.

AnkleWork

+1; a sound incremental approach.
It's like more fully characterizing the problem. The worst that could happen is vibration and somewhat reduced life. Since bike bearings tend to be over-built, you may never have a problem with the hub in practice.

fietsbob

Yea take, the axle out , clean off the grease , inspect .. cup race on the Non-drive side cannot be replaced , if it's damaged

you bought damaged goods, you were taken advantage of .. Cassette driver can be replaced , axle, both cones can be replaced .

Its the non drive side, the part with Both spoke flanges on it, that cannot be replaced *, then you get another Hub. whole thing ..

* https://en.wikipedia.org/wiki/Ship_of_Theseus

prathmann

If it was turning smoothly when purchased years ago my guess would be that the bearing was adjusted a bit on the tight side so all the grease was squeezed out of the contact points between the balls and the cup&cone. Over time a bit of either corrosion or metal-metal fusing developed in that contact area with no grease present. I doubt that the amount of damage is all that significant and would be inclined to just reassemble the bearing with sufficient grease and adjusted to barely take out all play but not so tight that there's any binding. If the damaged areas are as small as I'd expect them to be then the normal wear as the balls rotate should take care of smoothing things out once you start riding the bike.

OndrejP_SK

Thanks for your opinions.

I would vote for the impact on LH side or some chamical reaction between the metals if the grease has been pressed out by too tight assembly. Just too tight assembly would probably make the dimples on RH side cone too.

The hub is already laced to a heavy duty touring rim, but I think I will have to replace the hub and make another wheel for touring, because when you're on tour, you want reliable wheels. However I will probably use the hub for something less demanding.

ThermionicScott 

Got any pics? I highly doubt that impact or being assembled too tightly by itself would do this, more like corrosion over time. I'd agree with @prathmann that you could probably repack it and it would wear smooth again. Maybe you could plan on repacking it again after some riding.

Andy_K 

Interesting that this came up so recently. I just posted a picture on another thread of what I think is the same problem. I discovered it last night. My hub is very old and definitely used, but I've got a picture of the dimples:



In my case, it looks like the hub was designed to use a keyed washer and at some point it got lost because when I got it the NDS had just a cone (which doesn't look original) and a locknut. There didn't appear to be a way to tighten the nut without clamping down on the bearings, which someone obviously did. When I got the wheel, the wheel would barely turn on the axle. I had hoped it would be as simple as loosening the adjustment. Sadly, it looks like it will instead be as simple as getting a new wheel.

CliffordK

Whew...
7 bearings? Are they caged?

Cone and locknut, but they can't be tightened like normal?

ThermionicScott 

That's what I was wondering, too. I bet if it were repacked with 9 or 10 loose balls per side (whichever it needs) it would turn better. Or if you can go up or down slightly in bearing size, they'll run in a slightly different part of the bearing track. That would be if you're dying to experiment.

Andy_K 

Yep. Looking at the picture, I'm trying to convince myself that the usual wear line on the cup is above the dimples and that if I repacked it with a proper number of loose balls they would just glide past the dimples. That's probably just wishful thinking, but I'll take a closer look before I dump it in the recycling bin.


I don't know, maybe I just haven't thought through the problem enough. The drive side cone doesn't have flats for a cone wrench. It's got a stack of spacers between the cone and the locknut and none of it wants to move. There are notches in the axle, so I figured it must be some kind of keyed washer system. On the NDS I suppose the cone and locknut could be tightened together, but even though that cone does have flats for a cone wrench, it doesn't extend far enough for the flats to clear the hub flange (and is generally covered by the dust cap when the cone is against the bearings. I suppose it might be possible to tighten the NDS cone and locknut against one another before installing the axle and adjust the drive side cone by hand before installing the spacers and lock nut.

In any event, a previous owner didn't do that, so I think it's all academic now. It's a cheap old Raleigh wheel that I got with a $30 clunker, so it's not a major tragedy. I was just hoping the wheel could be saved.

AlexCyclistRoch

Andy,
What you have there is the best pic of a Brinnelled bearing race I've ever seen.

tortron

I had a similar issue with a front LX hub from a german online retailer......


it lasted 30000km till I wore the rim out anyway