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Suspension bearing failure

hathill's picture

By hathill - Posted on 27 December 2012

NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.

Anyone seen a full complement bearing do this before?
They were replaced back in May 2012 and have been running fine until I noticed that the seal was protruding. Was it just bad luck that the assembly slots were lined up and the ball worked its way out or are full complement bearings the wrong choice as some people advise?
All the other bearings feel fine, and no misalignment I can see/feel etc.
The last image was taken nack on the 3rd of December prior to rinding the Great North Road. You can see the seal is almost off.

DigDig's picture

Not sure what you mean by full complement not a term I have heard but a ball bearing is the wrong type you need a roller bearing.

Muninjitsu's picture

Ball bearings are not designed to take the impact which you get on a pivot joint, needle/roller bearings are much more suited to this application.

hathill's picture

DigDug, full complement means the bearing is fully loaded with balls rather than having a cage to space them out inside. This means that there is a small slot machined in the edge of the inner and outer race to allow the bearing to be assembled.
Char, Giant installs ball bearings on all their bikes as I'm sure lots of other manufacturers do. I'm not sure that a straight roller is any better as it has to be able to cope with some non-radial force. It would really need to be a pair of tapered roller bearings. I'll chalk it down as a one-off at this stage.

From Wikipedia...


In a slot-fill radial bearing, also referred to as a full complement design, the inner and outer races are notched on one face so that when the notches are aligned, balls can be slipped in the resulting slot to assemble the bearing. A slot-fill bearing has the advantage that the entire groove is filled with balls, called a full complement, resulting in a higher radial load capacity than a Conrad bearing of the same dimensions and material type. However, a slot-fill bearing cannot carry a significant axial load on the loading slot side. Also, the slots cause a discontinuity in the races that has a small but adverse effect on strength. Note that an angular contact bearing can be disassembled axially and therefore is a full complement design."

DigDig's picture

Thanks mate I would just call it a loose race or cageless myself.Hopefully its just a faulty bearing or not the best quality look for engineering bearings from a bearing shop.The higher abec no. or the amount of Zs on the end of the number eg 6076z not as good as a 6076zz.

Vinno's picture

Never had an issue with mine failing and both my duelies have them. I pop the seal off every now and then and push some grease through mine. My Pivot is 4 years old and still on the same ones.

My other is a single pivot Bear Bike and it is about 14 years old with the bearings near the bottom bracket. It hasn't had many km's over the last 8 years and I have replaced them once.

The picture of yours looks pretty dry. Best to get some decent quality SKF or similar from one of the bearing suppliers, they work out pretty cheap too.

hathill's picture

Thanks Vinno - SKF/NSK/FAG etc were my next port of call - I did clean and re grease the ones that came originally and got another year out or them. I have temporarily put one of these old ones in after a good clean and repack. The factory bearings do not have full contact seals (WTF, it's a mountain bike) which is a bit piss poor on Giants part. Also, the later model Anthems use bolts with larger heads to protect the exposed outside of the bearing better.
Forgot to ask - are your bearings full complement or standard caged type?
Anyway, lucky to pick it up in the shed and not out on the trail somewhere.
Happy New Year for tomorrow evening.

Vinno's picture

Mine are full type bearings. Here is a link to SKF and they explain the use of the bearings. Basically the type you mention are for heavier loads due to the number of balls. Also they are not designed to spin as fast.

I remember back in my skateboarding days the bearings we used had metal seals both sides whereas the ones on my Pivot have a larger rubber seals. I am pretty sure the skateboard bearings were caged which space the bearings for higher speeds. I remeber pulling them out and regreasing them as well.

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