Destroyed bearings

[dsharman1]

Hi, I was on my bike yesterday when the back wheel went wobbly and to cut a long story short, basically one of the rear wheel bearings had totally fallen apart. Now replacement isn't a problem but what I do want to know is what could have caused it, they hadn't been in very long, maybe 1000km max and they are good quality bearings (fag) , any ideas? [/quote][/list]
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Aprillia rs 50 2000
derbi city cross 125 2007 (RIP 08/2015)
Honda CG 125 2001

[Pete.]

My opinion, either:

1) improper installation
or
2) Grease washed out with a jetwash
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Pol Anorl]

i had this happen 3 times on my old divvy, 4th time i fitted myself instead of a garage and they where fine..

3 times with bad bearings or badly fitted.
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GOOD GAME BODYGUARD: https://i.imgur.com/8WePGgf.jpg
20:30:37 Pyro.: I don't sort of like men, I take every advantage to choke on dick.
Jewlio Iglesias: You live in Liverpool - Chances are, the front door has already been kicked off the hinges

[dsharman1]

I don't know if this would affect it but the edge which houses the bearings on this side dies have a slit out of it but the bearings are still snug in there
____________________
Aprillia rs 50 2000
derbi city cross 125 2007 (RIP 08/2015)
Honda CG 125 2001

[Pol Anorl]

do you buy cheap shit bearings?

don't lie either itll waste our time trying to help
____________________
GOOD GAME BODYGUARD: https://i.imgur.com/8WePGgf.jpg
20:30:37 Pyro.: I don't sort of like men, I take every advantage to choke on dick.
Jewlio Iglesias: You live in Liverpool - Chances are, the front door has already been kicked off the hinges

[Major Doss]

Early FireBlades munched RW bearings, just saying. As has been said, do it yourself with quality bearings, and replace the the sprocket carrier one, if fitted, I dunno the bike. Odd that the FAG let go, good brand....

[dsharman1]

The bearings were good quality ones, the brand was fag, I was told they were decent, also I did buy the high speed variety.

[quote
Early FireBlades munched RW bearings, just saying. As has been said, do it yourself with quality bearings, and replace the the sprocket carrier one, if fitted, I dunno the bike. Odd that the FAG let go, good brand.... Thinking
[/quote]
I am not aware of there being one on the sprocket, the last one was fitted at the same time as all of the bump there 4 which seem fine which were all fitted by me with guidance from my dad since I haven't done it before
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Aprillia rs 50 2000
derbi city cross 125 2007 (RIP 08/2015)
Honda CG 125 2001

[Pete.]

There certainly is a bearing in the sprocket carrier.

I just thought of another reason for the bearings to fail prematurely:

3) missing tubular spacer between the wheel bearings

If you look at the colour-shaded photo (or a Hayabusa wheel) in this thread you'll see the spacers shaded red.

https://www.bikechatforums.com/viewtopic.php?t=221851

If either of the two internal ones are missing it will trash the bearings very fast indeed. You'll also probably notice more thread than usual poking through the axle nut.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[salem1987]

[Polarbear]

My guess, presuming all components have been fitted correctly, would be a spanner monkey hammering the bearings in by hitting the inner race or the guard rather than the outer race.
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Victory Cross Country American tractor.

[evilzed]

I know one of my rear wheel bearings developed very small amount of play but enough to feel it in the handling, I adjusted the chain about 1k miles prior and used the manuals specified 93Nm of torque on the axle nut however that was on greased threads which increased the torque so was most likely the cause.

I swapped all 3 bearings out (inc sprocket) and used 70Nm instead and all was fixed.

[dydey90]

It's amazing how easy it is to damage a bearing during fitting. I once got told that 80% of failures are in the first two months of service due to rough fittings.
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This post is probably not serious and shouldn't be taken literally.
Past: CBR125,ER6f NINJA 650, ZZR600 Current: VFR750

[Kickstart]

[Stalk]

I might be wrong but, you say you fitted the high speed ones. C type? If so I believe that they are incorrect for bike wheel bearings as they are designed to go a lot faster and are made loose so that they expand to the right size when in use. Use normal ones.
Feel free to correct me people.
Cheers
Stalk

[evilzed]

[dsharman1]

i think i may have found the culprit, the spacer in the middle of the wheel in between the 2 bearings is a little bit to short so it is not quite up to the bottom of the lip which the bearing sits on so it isn't making contact with the center of the bearing.now just to make a new one up tonight when i get back
____________________
Aprillia rs 50 2000
derbi city cross 125 2007 (RIP 08/2015)
Honda CG 125 2001

[Kickstart]

[dsharman1]

i had the front wheel out when i first got the bike because all bearings needed replacing,and the one in the front is a lot shorter than the rear one. but i have replaced the rear spacer and fitted 2 new bearings and sop far all seems well but i have only gone about 8 miles on them this morning
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Aprillia rs 50 2000
derbi city cross 125 2007 (RIP 08/2015)
Honda CG 125 2001

[Pete.]

The best way to check for significant axial loading is to leave off the dust seals and mount the whole rotating assembly then spin it by hand. It should spin a good few turns and coast to a stop. If you witness it being 'braked' it's time to investigate.
One thing that's quite common to find is that the bearing seat get's nicked when drifting out the old bearing raising a burr. This causes the new bearing to sit canted on the seat when it's clamped up by the axle. Could be why your tube spacer appears short.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good