Mr_Pickles3

Hi! First post on this site

Im going slightly mad at the moment: I’ve tried repacking three hubs different now, all with the same results. Today I’ve been repacking a hub which was very smooth beforehand as the LBS man recommended it, but it is now scratchy and coarse feeling when spun in the hands. The hub in question is only a few months old and is cup-and-cone.

Initially, I put loads of grease in (as with the other two “test” ones that I attempted), with the result being a scratching/catchy hub unless I adjust the cones until there is play (which is obviously no good). So, thinking the problem might be too much grease, I cleaned it out and repacked it again with less (so the bearings are just held in place by the grease). However, the hub still feels scratchy/catchy, no matter now tight or loose I adjust it. It’s so annoying!

I’m using new cones and bearings with a non-bent solid axle, and the races are still in great condition (as expected after only a few months) so I’m at a loss as to what I’m doing wrong. I know it’s not going to be perfectly smooth, but currently the axle either catches or it feels ‘rumbly’ when spinning the wheel.

Is is there anything I’m doing wrong? Any suggestions at this stage would be very appreciated!

trailangel

Why would you change the cones and bearings on a hub that is only a few months old?
Your skills may be in question.
I cannot watch what you are doing.

Mr_Pickles3

The guy at the LBS reckoned they were rough and needed investigating. They were generic wheels so I saw where he was coming from. Still, they shouldn’t be rougher than when I started! I’m following very book/online guilde that I’ve found about it, so that’s why I’m not sure what’s going on. I thought the “test” hubs could have knackered races as they were old wheels, so decided that the real test would be if the same thing happened with the new wheels.

trailangel

Adjust them better. It's the slightest turn on a wrench between rough and smooth.

Mr_Pickles3

As I mentioned, I can’t find a spot where they’re smooth where there’s no play. I’ve spent an hour trying to do it now with no success

Moe Zhoost

Are you using caged bearings? Perhaps you installed the cages backwards. The open side of the cage goes toward the cone. Long shot - are the bearing balls all the same size? If so, are they the proper size for the hub?

Re: cone adjustment - a bit too loose is better than a bit too tight. A tiny,tiny amount of play is ok

dsbrantjr

Do not mix balls from different lots, or new with used; the size variation within lots is much less than from lot to lot. If the balls are not closely matched only the largest few will take the load

masi61

You mention that they are solid axles. Just curious about the threads - are they coarse or fine? When you tighten the cones, is there any resistance from the axle threads. If they are poorly cut threads on the axle or poorly tapped threads in the cones, it will make your job much more difficult. If they are fine thread and sharply cut like on old Dura Ace 7400 hubs, you can achieve that perfect (near) zero play and feeling buttery at the same time.

Maybe post a picture of the hub showing the axle, cones, spacers and locknuts. Show it disassembled so we can see what the bearing look like. And just to be clear - are you using the proper size cone wrench and a proper size metric wrench for the locknut? This is important!

Also, since you aren't near your goal of smoothness yet, it should still be mentioned that once you get the play out of the bearings and still have smoothness, your final preloading of the bearings can be done dynamically with the wheelhub bolted in the frame. Often, bearings that were perfectly adjusted while off the bike will now be too tight, requiring that the cones be backed out less than 1/4 turn with 2 cone wrenches. You can unlock the locknuts for this step or just leave them locked and just use 2 cone wrenches (one on each cone - so same size) and back one of them off counterclockwise ever so slightly.

dsbrantjr

Way, way less than 1/4 turn. Likely less than 1 degree. I set mine up with the locknut slightly tight but still movable, then make the final adjustment by tightening the cone or locknut, depending upon needing looser or tighter adjustment, while holding the other still, until they are finally locked and adjusted. You need to kind of creep up on it. It is difficult to describe, perhaps others here will describe it better.
Or these guys:
https://www.sheldonbrown.com/cone-adjustment.html
https://www.sheldonbrown.com/brandt/...djustment.html

Damaged or lower-quality parts may never be truly smooth even when properly adjusted.

Brocephus

First, can you tell us exactly what wheels we're talking about here? ( mtn or road? Brand/model of hub?)



I've successfully done a number of cone/bearing hubs over the years, but I recently tried re-packing an old set of Wellgo pedals, and ran into the same issue. No matter what I do, it's catchy/grindy/rough.....just wrong. Even if I leave some noticeable play.
I have no clue what's up here, but it sounds just like what you've run into.



If they were near new, and "very smooth", why did you overhaul them?

I was going to ask if you over-greased them, because I've observed you can cram too much in there, but it seems you've addressed this already.
Also, are you 100% positive you haven't misplaced a bearing ? (I've been on my hands and knees waving a big retrieval magnet over the carpet, more than a few times, LOL ! And not just for hub bearings, but gun,guitar, and other microscopic parts.)


I don;t blame you for servicing them, but I wouldn't be investing any money on a set of generic OEM wheels (if possible, I just assume my 200 lb self is gonna bust some generic spokes, since it's happened a few times, so I don't give them the chance anymore, I just replace them right off with something better. BicycleWheelWarehouse, does some very solid wheelsets, surprisingly inexpensively. Their most economical stuff naturally ain;t gonna win any low-weight competitions, but they can hook you up some robust, name-brand rims, laced up with Swiss DT's, to some XT or 105 hubs, for well under $200 delivered.
It's worth consideration of these rims don't fall into line.
As mentioned above, very fine adjustment increments can make a big difference, and it can take quite a few tries to get them where you want them.
Also, keep in mind that the force of a QR clamped down actually bends the axle a small amount. So a slightly loose hub, can tighten down perfectly, or a perfectly adjusted hub ( off the bike), can end up too tight, once clamped into the QR.

speedevil 

If the axle is solid, there can't be a QR problem here. So we're talking about a solid axle, held in place with nuts on the outside of the dropouts. Not top of the line, but should be perfectly serviceable for a long time. On-the-road tire/tube repairs are a bit more complicated, but that's not a topic here.

My guess would be that tightening the outer nut is cause the cones to move inward on the axle, tightening the bearing balls between the cone and the race.

To do this properly, you'll need to use a cone wrench to hold the cone in place while you tighten the outer nut. But you have to choose a side that will be tightened first (the "fixed" side), and then do that. Then adjust the opposite cone (the "adjustable" cone) to get the play out. Now, since one side of the axle is firmly clamped into it's dropout, hold the "adjustable" cone with a wrench while you tighten the outside nut.

That should do it, unless there is some fault with the cups, cones, or bearings.

andrewclaus

I disagree. Any play at all puts all the load on just a couple of ball bearings and leads to failure. Ideal adjustment has all BBs contacting the races at all times. There was a long thread a few months ago about bearing preload, so we don't need to go into that here. Look it up if you're interested.

Use this guy's method for final adjustment: It works.

blamester

You will never get them perfect.
And after riding them for a while they will adjust themselves they almost always do.
Did you notice anything while you where riding the bike?
After an hour of adjustment you know where the best spot is.
There is grease in there so you know thats ok.
Ride the bike and keep an eye on them.
That is as good as it will get.

Mr_Pickles3

I'm just using loose bearings at the moment, but thank you for the suggestion I was initially using the old bearings with tow new ones (a couple old ones fell on the floor and got dirty so I thought it best t replace them), but decided to follow dsbrantjr's advice and replace all of them with new bearings from the same bag to make sure this wasn't the problem

The threads don't seem to be a problem; the cones screw on with no resistance. And I am using proper cone wrenches and spanners, so I'm confident it's not a tool issue! Buying the stuff to do it myself was supposed to save me money by not needing to go to the LBS but it's not working so far

Mr_Pickles3

The wheels are some "NOS" chromed steel ones for my 1970s classic Peugeot bike...which have been pretty rubbish from day one (loose spokes, not true, etc). They've been fine for a few months though after (a different) LBS set them up for me. The reason I decided to overhaul them was because recently my new LBS guy was very convinced that they were rough/needed looking at, and I'd read that it wasn't that much of a difficult job/I heard new hubs sometimes lacked grease which I may as well address by putting new stuff in. I think he might have been talking rubbish though And I'm not missing any bearings - the same number have gone back in as came out!

At the moment, the best I can do where there is no "binding" at gives quite a lot of play. I need to fit a new freewheel this week, so I'll have another go then using some of the methods suggested here. I'm not expecting perfect smoothness, but I'm guessing that there should be no obvious binding at all, or "rumble" feelings?

davidad

You are kidding aren't you. The tolerances between batches of quality bearings so small as to be insinificant.


From: jbrandt@hpl.hp.com (Jobst Brandt) Newsgroups: rec.bicycles.tech Subject: Re: How Bearings are Made Date: 22 Nov 1999 23:05:20 GMT Roger (who?) writes: > Did you know you should only ever use ball bearings from the same > batch in one side of a race? They're not exactly the same size > between batches. Never simply replace that naughty one that bounced > into the corner of the garage - replace the other 10 (or whatever) > too!

You are making this up. The tolerance between bearing balls is so small as to be below a small fraction of the elastic compliance of the steel bearing. Besides, the races of bicycle bearings are so rough that a tight bearing feels lumpy. In high precision bearings used on computer disk storage devices, preload causes a smooth viscous drag. Even for these bearings the balls are not identical but are made to a prescribed tolerance. I don't believe I understand what you mean by the same batch. Each bearing is not made in the same finishing process as the others in a shipment of balls. Jobst Brandt <jbrandt@hpl.hp.com>

davidad

Bike cups are not necessarily perfect and you could have a slight lumpy feel when adjusting with a preload as is needed with a solid axle.

dsbrantjr

Actually the difference is significant enough that the ABMA STD-10 specification allows (for Grade 25) twice the tolerance within a shipment to that of a single lot.

That difference, 100 microinches (a 10th of a thousandth, 0.0001")vs 50 microinches, is easily measurable and can be significant if one wants "buttery-smooth" running.

Ball Size Grade Tolerance Definitions | Hartford Technologies

Moe Zhoost

Well, I do agree with you. I use the method recommended by the Barnett Bicycle Institute myself. However my experience helping novice DIYers is that most adjust them much too tight or much too loose. Having a target a smooth feeling axle, if they can get there but only with a barely (and I mean barely) perceptible amount of play, I say good enough for most.

The video you shared is good, but gives no sense of what this experienced mechanic is feeling when he says too tight or too loose.

Moe Zhoost

Wow, Jobst Brandt is a guru and I accept most everything he says. Nevertheless, I have to say that, as @dsbrantjr recommends, I never mix bearings from different batches. OCD at work I guess. I don't have a way to measure the tolerance between batches so I reckon I'll give a nod to Jobst and then do what I do.

grizzly59

I would look at the cones. The replacement cones from Shimano were all very good, but the others for house brand hubs not so much. I have had to chuck a dummy axle in a drill, mount a cone, and sand the running surface with some approx. 800 grit 3M auto body paper and my fingers to smooth cones out to where they should be.

You can check bearing balls with a good micrometer and pick a set good enough for you.

davidad

In other words, much ado about nothing.

3alarmer 

...with a loose bearing hub, the most common cause of this issue you describe is either one too many bearings added to the race, or one of the bearings drops out of the race and doubles up as you tighten the cones. The grease is sticky enough to hold them initially, but you still need to be pretty careful as you tighten both cones to trap the bearings between cone and race.

But it's just a guess. Some of the more modern stuff on the lower end of quality feels rough or loose with no possible optimal adjustment point in between.

Kovkov

Try a new axle. I had the same symptoms several times and even if the axle appeared straight, after installing a new one everything was fine.

dedhed

Define "shipment" and "lot". Who actually thinks, that when purchased in the small amounts on a personal consumer level, the repackaged quantity they are getting is somehow from the same "lot"? And c'mon, it's a bicycle, maybe a couple hundred pound load and a few hundred rpm isn't really requiring precision bearings. I suspect most failures are due to lack of maintenance, lack of lube, contamination, or misadjustment, not the precision of the component.


Which lot is mine?