Rear Hub Service

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Xavo.au

Likes Bikes and Dirt
Just did a bit of a service on my rear hub - Shimano Deore cup and cone type.

Anyway, got everything back together and the wheel spins better, but I'm getting a slight vibration and I'm trying to troubleshoot.

So I reckon it's either:
  • Not enough grease packing the bearings/axle
  • Cones too tight
  • Cones not tight enough
  • Lockring on non-drive side too tight
  • Lockring on drive side not tight enough

Any suggestions?

Cheers.
 
Servicing Shimano cup & cone is a bit of an art. You need to tighten them just enough off the bike so there's still a slight 'rattle' when you grab the axle and wiggle it. Then when you put it back on the bike and tighten the QR this slack will be taken out and they should run smooth and free without any movement if you grab the wheel and move it from side to side. Takes a few tries to get it right, but once you do its very satisfying.

On a rear, also check the freehub hasn't come loose. No amount of adjusting the cones will get rid of play if its the freehub that's loose, as the driveside cup is actually part of the freehub. The freehub can only be tightened with the axle removed and a large hex key inserted into the centre.
 
Alright cheers for the advice mate, will give it a go. I don't think the freehub is loose, it's just a slight grinding/vibrating sensation. Could need a bit more grease, I don't know how much to chuck it but I gave it a good go.
 
Xavo.au said:
I don't think the freehub is loose, it's just a slight grinding/vibrating sensation. Could need a bit more grease, I don't know how much to chuck it but I gave it a good go.
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serviced on a few weeks ago.... reminded why I hated them and love sealed bearings!
i wouldnt go as far as saying its a dark art... but it does take a few goes to get it right.
I normally finger tighten the nut and back it off 1/4 a turn and its sweet!

Can you comment on the actual service you did?
did you wipe out all the grease and actually degrease everything?
check for damage? ie pitting on cup/cone? ball bearings? any metal shavings/dust?

does the wheel at least spin freely? or does it grind to a halt?

use lots of grease... but I choose one thats light (also know of people who actually use thick grease just to minimum service intervals)
either way... as long as you grease it, it will work....Unless we are talking minimal/insufficient grease, then adding more will just increases drag.
 
Xavo.au said:
Alright cheers for the advice mate, will give it a go. I don't think the freehub is loose, it's just a slight grinding/vibrating sensation. Could need a bit more grease, I don't know how much to chuck it but I gave it a good go.
Click to expand...

Ok if its a grinding then sounds like you've tightened it too much. As I said above, it should be loose enough for the axle to rattle a bit when off the bike, then when you do the quick release up it will tighten it up a fraction more, but it should still run smooth. If you spin the wheel it should go about three revolutions, then reverse direction and settle where the heaviest part of the rim is - either the tyre valve or the rim weld opposite the valve. If its sticking instead then you've done it up too tight.

As chopstix says, also worth checking the cones & cups aren't pitted, because if they are you'll not be able to get it running smooth ever again. Best way to check them is to remove and wipe off all grease then run a ballpoint pen around the shiny groove in the cup/cone. That'll show you if there's any pitting - which will mean a new set of cups, cones, and balls.
 
When I do the following when I service cup/cone bearings:

- Remove axle and balls from the hub,
- Thoroughly clean all components, including the space between the cups in the hub,
- Inspect both the cup and cone bearing races for any damage. Cups are pretty durable and they normally last ok but cones will be the ones to show any damage and is pretty obvious when you look at them. Any holes or chips in the "shiny" section when the bearings rolls is damage and the cones should be replaced. Damage in the cups is different as cups are generally not replaceable and generally requires the hub to be replaced. At this stage, you might as well get a new wheel,
- If all components are serviceable, I will install some grease into the hub into the cups and install all of the balls. The grease holds the ball in nicely but you still need to be gentle not to bump them out,
- I then install the axle. Ensure the cone and locking nut that are still on the axle are pretty tight and install into the hub with the other cone tightening up until finger tight, when finger tight, install the locking nut and lightly do up,
- I then tighten the locking nut up or undo the cone that I just put in. I try and find the balance between the graunchy feeling and loose bearings. If the bearings feel tight and graunchy and the locking nut hasn't been fully tightened, using cone spanners, I will hold the cone and locking nut (both on the re-installed side) and loosen the cone ensuring the axle doesn't turn, if the bearings go loose, tighten the bearings using the locking nuts. Keep on going backward and forwards like this until the locking nuts are tight (and I mean tight) and the wheel spins freely without and graunchyness or looseness,
- If when you reinstall the wheel, the qr binds the bearings then you haven't tightened the locking nuts sufficiently. Remove the wheel and continue the above until the locknuts are tight and the qr don't bind the bearings.

Last word of advice though. IMO, cup/cones bearing systems are not suited for offroad applications. Yes, you can might be able to make them spin better than sealed bearings and their "easily" serviceable but you need to service them regularly and it doesn't take much to screw a cup/cone hub and mtbing generally is no where near as "clean" as road or track riding. I learnt this lesson the hard way and screwed a rear XT hub in the first outing. Generally you will get at least 12 months out of a set of bearings in a sealed hub without touching them and then your up for about $20-$50 (depending on the bearing) to replace them. I also know of guys that have got 4+ years out of sealed bearing and they are racing most weekends and the wheels still spin nicely.
 
Right sweet, thanks for that. I'm fairly sure it's just slightly over tightened. I did the cone by hand, but the lockring with the cone spanners, will have a fiddle later on and see if I can get it right. Will spins freely until it runs out of moment, no grinding to a stop or anything like that.

Chops, I took all the bearings out, removed grease from the cup & cones and inspected for damage, degreased the bearings and inspected them for damage and then regreased it all and put it back together. Using a fairly thick grease, but it doesn't seem to impact things and it's a plus if it increases service intervals.

I was actually surprised, there wasn't a thing wrong with any of it.

They're only deore hubs, and while I can't afford new wheels/hubs at the moment it's good to get a look inside them so I know how to service it when I get better wheels down the track - so all advice is appreciated guys, cheers!
 
Xavo.au said:
Right sweet, thanks for that. I'm fairly sure it's just slightly over tightened. I did the cone by hand, but the lockring with the cone spanners, will have a fiddle later on and see if I can get it right. Will spins freely until it runs out of moment, no grinding to a stop or anything like that.

Chops, I took all the bearings out, removed grease from the cup & cones and inspected for damage, degreased the bearings and inspected them for damage and then regreased it all and put it back together. Using a fairly thick grease, but it doesn't seem to impact things and it's a plus if it increases service intervals.

I was actually surprised, there wasn't a thing wrong with any of it.

They're only deore hubs, and while I can't afford new wheels/hubs at the moment it's good to get a look inside them so I know how to service it when I get better wheels down the track - so all advice is appreciated guys, cheers!
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Also, bearing balls may get a few flat (flatter?) spots without actually pitting the races... worth checking.
Maybe you already checked for that as you mention you inspected the bearings.
 
Loose ball bearings are so cheap that you should just replace them when you do a service. You won't pick minor bearing wear by eye.
 
Warp said:
Also, bearing balls may get a few flat (flatter?) spots without actually pitting the races... worth checking.
Maybe you already checked for that as you mention you inspected the bearings.
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Yep checked them for damage/flatspots and couldn't find anything. Also kept the non-drive side bearings seperated from the drive side bearings so that they went back into their original places.

slippy said:
Loose ball bearings are so cheap that you should just replace them when you do a service. You won't pick minor bearing wear by eye.
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Fair enough, the video I watched suggested keeping the bearings matched to each side so they'd be bedded in when the hub is rebuilt.
 
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