Cup and cone bedding-in

[Trax]

Hi,
Is it normal that after replacing a cup-and-cone bearing for it to become loose after the first and second rides? Twice now I have had to take up the slack. Is it because I packed it with grease and as the grease moves around, you get some 'play' in the bearing? How many times am I likely to have to tighten it before it 'settles down'? Thanks for any help with this.

 

[Jody]

Is the lock ring nipped up correctly?

 

[Trax]

Yes, definitely. I replaced one of the two bearings, and then tightened so that there was no play, and then tightened the locking ring.

 

[Jody]

It shouldn't need to be tightened times over so something is going wrong. Extra grease packed in would be forced into the hub until the slack is removed.

 

[presta]

Are you sure you pressed the new bearing fully home when you fitted it?

 

[Dogtrousers]

Maybe.

I have noticed on a couple of occasions in the past cup and cone bearings having play after I've done maintenance. TBH I've put it down to my own incompetence - I didn't adjust them properly or didn't do the lock nut up right. But I suppose working loose could have been a reason. But in my case incompetence is generally a more likely explanation.

 

[Ajax Bay]

No, it is not normal.
I cannot think of any other reason except that you haven't tightened the lock nut (solid spanner) and the cone (cone spanner, preventing it from turning) together with sufficient 'vigour'. Using normal length spanners you cannot over tighten.
Not sure quite what you mean by "I replaced one of the two bearings". There will be ?9 or 11 bearings on each side.

 

[Jody]

The only thing I can think of is that the axle is moving when nipping the lock nut, effectively loosening the cone on the opposite side and creating slack.

It should be impossible for the cones to unwind when finally locked in the frame/fork.

 

[fossyant]

I would suspect you've not tightened the nuts up properly. I always leave the drive side , and only undo the non-drive side. Another tip, is to leave the slightest amount of play in the bearing as this is removed when the QR is tightened up.

 

[Trax]

Thanks all. I suspect I have been too cautious with the tightening. Perhaps I should fully tighten (until the crank won't rotate), and the slacken off. This will presumably ensure that the bearings are pushed fully 'home'.

Ajax Bay - there two bearing, each with 9 balls enclosed in a race. I replaced one set.

Jody - I didn't undo the drive side - it wouldn't budge. That's why I replaced like-for-like. If I'd have been able to get both sides off, I'd have put a canister in.

Some great tips everyone - I'll have one more go before removing the bearings. There's a chance I suppose that one of the bearings has failed. Unlikely, but can't be discounted.

 

[Jody]

Perhaps I should fully tighten (until the crank won't rotate), and the slacken off. This will presumably ensure that the bearings are pushed fully 'home'.

Jody - I didn't undo the drive side - it wouldn't budge. That's why I replaced like-for-like. If I'd have been able to get both sides off, I'd have put a canister in.

Point 1 will crush your bearings

Point 2 is my explanation. The passive nut on the opposite side won't move on the threaded axel but rather the whole axel will spin when tightening the lock nut. Effectively slackening off the bearing tension without you noticing

 

[Trax]

Point 1 will crush your bearings

Point 2 is my explanation. The passive nut on the opposite side won't move on the threaded axel but rather the whole axel will spin when tightening the lock nut. Effectively slackening off the bearing tension without you noticing

Ok. Thanks. So what's the answer - given that the drive-side is too tight to undo? I can't say I understand your point fully. I can't visualise any part of the assembly that can 'spin'. Neither the drive-side threaded insert, or it's locking nut have moved. They are stuck fast. Thanks.

 

[fossyant]

Getting the cone just tight enough is a bit hit and miss as sometimes when tightening the lock nut it can cause the cone to tighten, but you must make sure the cone and locknut are tight. I sometimes use another spanner on the drive side to hold the axel still.

 

[Moodyman]

This is a Shimano hub, but they all work similarly.

Put the hub back together and tighten Y until it touches the hub bearings. Then wind in Z until it meets Y.

Now, use 2 spanners to tighten Y and Z together. Use lots of force (by hand). I think this is where you’re going wrong and it allows Z, and in turn Y, to loosen.

Now wind in Z. This will make Y move in automatically. Keep turning hub by hand to check for smooth running. You should have ever so slight play in the bearing when you move hub up/down by hand. That play will disappear when you tight quick release.

 

[Ajax Bay]

Thanks all. I suspect I have been too cautious with the tightening. Perhaps I should fully tighten (until the crank won't rotate), and the slacken off. This will presumably ensure that the bearings are pushed fully 'home'.
Ajax Bay - there two bearing, each with 9 balls enclosed in a race. I replaced one set.
Jody - I didn't undo the drive side - it wouldn't budge. That's why I replaced like-for-like. If I'd have been able to get both sides off, I'd have put a canister in.
Some great tips everyone - I'll have one more go before removing the bearings. There's a chance I suppose that one of the bearings has failed. Unlikely, but can't be discounted.

Still disconcerted by your narrative.
"if I'd been able to get both sides off" Sorry? Take off the lock nut, spacer and seal/cone from the left side. Pull the axle out 'complete' from the right side (through the freehub (assumed)), taking care to catch all the balls. Access to "both sides".
"cannister" - assume you mean a set of caged balls. These offer no better bearing effect: you're well off with loose balls and dollops of grease. With the axle (complete with one locked on cone and locknut) out you can clean everything and insert new bearings (balls).
"too cautious with the tightening" All that done screw the LH cone on by hand till finger tight and then back off a quarter turn (assume QR). Lock; like you mean it.
"a chance that one of the bearings has failed" - do you mean one of the balls has broken on the RHS (which you have failed to access)?
You will know by spinning the wheel in your hand whether this is the case.
I, like you ("I can't say I understand your point fully"), don't think @Jody 's cunning idea has merit. I just don't see the mechanism for the effect they describe.