Borked bearings

[wheeliebin]

At the weekend I took the hub bearing apart on the back wheel of my MTB because it had started making alarming clattering noises. The left side bearings looked OK, but the ones on the cassette side were running in what seemed to be a rusty paste. Thinking this was a bad thing, I then noticed that there were only 8 balls on the cassette side, and 9 on the left side. It's a Deore hub, everything I've read says there should be 9 bearings both sides. I'm sure I didn't lose one when I took it apart - Is it possible that one of the bearings has disintegrated completely? The hub hasn't been apart from new (woops), and has done something over 5k miles.

The cup looks in fairly bad shape, and the bearings don't seem very round either, so I think if I just just replace the cone and bearings it's not going to last very long. Should I try and transplant the freehub bit? Or should I just forget it and look for a new wheel or a decent second hand one?

 

[fossyant]

If the non-drive side looks OK, I'd buy a whole new Deore hub (same model) and use that as parts. Drive side bearing race is part of the freehub, and as the bearings are rough, this will be too.

Whole hubs are cheaper than the parts.

 

[Graham]

It must be rare for a ball bearing to disintegrate. However, if it did, the rusty grease should be quite gritty with the fragments of ball bearing. I tend to run things until they wave a white flag of some sort, so I would just stick some new bearings in (if they are no longer round/shiny) and ride it again. Then again, why not treat yourself!?

 

[BimblingBee]

Sometimes bearings can hide inside the middle of the hub once you've removed the axel!

 

[wheeliebin]

Thanks, I will try and transplant the freehub when I've found a suitable donor hub. In the meantime I've nicked the back wheel from my son's bike to keep me on the road!

 

[mrandmrspoves]

Disintegrating bearings is actually quite common place. I have serviced a number of bicycles and found bearings to be missing. Usually this is on low end bikes that have been neglected and I suspect that a combination of poor quality components, poor assembly and poor maintenance leads to this failure.
Better quality cycles, tend to be ridden by more discerning cyclists who wouldn't carry on riding something that grumbles, grinds and knocks for months on end (Note the operative term "Tend" !)
The most likely component to suffer severe bearing damage is the Bottom Bracket - see these little beauties!

 

[Eribiste]

Those seem a little past their optimum condition to me.

 

[mrandmrspoves]

Those seem a little past their optimum condition to me.

Not at all.....just needed a wipe over with a rag and a good dollop of Vaseline......

 

[wheeliebin]

View attachment 19337 Disintegrating bearings is actually quite common place. I have serviced a number of bicycles and found bearings to be missing. Usually this is on low end bikes that have been neglected and I suspect that a combination of poor quality components, poor assembly and poor maintenance leads to this failure.
Better quality cycles, tend to be ridden by more discerning cyclists who wouldn't carry on riding something that grumbles, grinds and knocks for months on end (Note the operative term "Tend" !)
The most likely component to suffer severe bearing damage is the Bottom Bracket - see these little beauties!

Mine's a Deore hub on a Trek MTB, so decent enough parts I think.
I only really noticed the nasty noise on the last commute that then prompted me to take it off the bike. I like to think I have a reasonable level of mechanical sensitivity, but as for preventive maintenance well,...errr..ummm.

Never mind, wherever the bearing went it will be replaced with new when the bits arrive.