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Bearing, bearings, bearings, Who thinks they know the score?
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Posted 14 years agoThe five main factors that contribute to bearing failure in MTB applications.
1)Bearing material.
2) Bearing design, caged or full comp also the seal design and interface between the seal and races.
3) Bearing greasing, how much and what kind.
4) Bearing tolerances.
5) Installation and maintenance of the bearings.Day 1 again
Day 2
1)Bearing material
As you can see the budget bearing being made of a much lesser quality material is not holding up very well.
The performance bearings are doing a lot better, the enduro in this test is doing a little bit better at this stage than the SKF’s, it is however an outdoor specific bearing. The SKF and most other performance bearings have a lot better seals than the enduro bearings, which is why a favour them. The seals make it much harder for contaminants to get into the bearing.
If you’re bearings rust on the inside you will get much quicker ware and there will also be a higher risk of them seizing.You will also spend far too much time replacing the bearings and get no performance gain.
If the bearing collapses which is what happens a lot with the cheaper bearings, a good example of this is the JNK bearings that Specialized run. You will have a much harder job replacing the bearings, me I could do without all the hassle.Seals as a sub category of bearing design.
Next I want to discuss seals and the outer also inner race interface between the two.The photo shows a budget bearing on the left an Enduro in the middle and an SKF on the right.
If you look closely you’ll see that there is a groove cut into the SKF bearings inner bore race for the seal to fit into. You will also see that the budget and enduro seals are almost identical, however the SKF seal is much thicker and has a superior design.
The SKF seal on the inner race interface has better quality rubber and is also ribbed, this helps it to keep the fit as tight as possible.The SKF seal will greatly reduce the amount of water and other contaminants that get into the bearing.
Let’s be hearing you then, you know you can’t resist!
Posted 14 years agoLet’s take a look inside some bearings and see what we see, Spazmastic yeah!!!
The bearing top left is an NTN it has seized as a result of bearing material (rust) building up, put simply not enough grease to weather proof it.
bearing at the top in the middle is an NBK same thing rust as a result of moisture entering the bearing and erosion occurring.
bearing on the top right is an enduro max as you can see the actual balls have rusted and caused this bearing to seize as well.
bearing on the bottom left is an enduro bearing, the problem this time is hardening of the actual grease at the end of its life expectancy and dirt build up.
Bottom middle bearing is another enduro bearing that has seized as a result of the grease coming to the end of its usefulness and also dirt building up.
Last bearing is one of specialized JNK brand and has bad rust and has seized as a result of this.
These are only some of the causes of bearing failure, they do show clearly that rust is a major factor.
Bearing material and design also greasing are the best ways to deal with this and stop it in its tracks.
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