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Bearing Myths updated: September 2007

Have my bearings failed?

I can not spin my bearings with my fingers. Are my bearings bad?

99% of the time the answer is no. There are misconceptions as to how free these bearings should be in their movement. The bearings are press fit, and are under a compression load and not easily moved by fingers alone.

One of our riders removed his 20mm front axle from his downhill bike and tried to spin the wheel bearings in his hub with his fingers, he could not. Was his wheel bearing bad? No, the bearings are under a compression load. Using your fingers to check a bearing is not the best test.

How do I test to see if my bearings are good or bad?

The best test is to put your bike in a work stand, remove the rear wheel and the rear shock from the frame. You should now be able to freely move your suspension up and down. If you have any side-to-side play or the suspension is stiff under actuation then there is a problem.

My suspension is loose feeling, what is wrong?

First make sure all fasteners are tight. All the aluminum fasteners should be torqued to15 inch-pounds. Secondarily make sure there is nothing bent or broken on the frame.
If there is still a loose feeling then there is the possibility of a damaged bearing or bearings. When bearings do fail its usually attributable to a lack of lubricant. Bearings fail when a ball shatters or the bearing race splits. If the bearing is notchy in its operation it can be serviced and made like new.

Loose feeling suspension can be many things beside the frame itself. Check your wheels, fork, and drive train components for excessive play.

Please contact Intense Service if you have a broken bearing.

My suspension is tight or stiff feeling, what is wrong?

In the test mentioned above if there is a tight or notchy feel to the suspension movement this is typically caused by the cartridge bearing binding in its operation, the binding is usually caused by the breakdown of the cartridge bearing's internal lubricant.

The cartridge bearing lubricant is made up of oil and a polyurethane paste like thickener. The paste is used to hold the oil content in place. Cartridge bearings also have seals over the bearing race area, this seal is designed to keep dirt out but will not stop water penetration.

If the bearings are exposed to water the seal will allow it to penetrate into the bearing race area. Continued exposure to water will wash the oil component out of the paste and will also wash in some contamination.

When the oil content is washed away and dirt contaminants are added the thickener will become hard, when this happens the balls in the bearing race have to roll over the hardened paste thus making the bearing feel notchy. In extreme cases the bearing will seize and will not turn.

The question now is are my bearings toast? No, absolutely not. It's a somewhat simple process to pop the dust seals off clean out the bearings with WD40 then re-grease your bearings, reassemble everything and you are good to go. A cleaning and re-grease should bring sealed bearings back to like new.

How long do bearings last, and when should I replace them?

Cartridge bearings as pivots last for years. 99% of the time your bearings do not need to be replaced. Unless the bearing actually fails, such as one of the balls shatter or the bearing race splits in half, the bearings should be fine. A simple re-greasing of the bearing and most of the time they are like new.

What do I do to make my bearings last long?

Keep your bearings greased up, bearings should always have plenty of lubrication. As long as there is lubricant inside the bearing it should continue to work for years.

Avoid pressure washers, do not use a garden hose directed straight at the bike and its pivot locations.

The best way to wash your bike is with bucket of water, mild detergent and washrag, apply soapy water to the bike with a soaking wet washrag, rinse the same way using a washrag. Avoid hosing down your bike as much as possible.

Can I re-grease my bearings?

If you are mechanically inclined, yes you can. If you are not then please take your bike to an Intense Cycles dealer near you.

What type of bearing does Intense Cycles use on their pivots?

We use a special type of bearing in all our frame pivots, called Enduro MAX type. What this means is maximum ball count of 11 balls and no retainer cage, these are designed as a pivot bearing, and are meant to pivot or seesaw back and forth, not acceptable for a spinning application.

Why use Enduro MAX type bearings?

Most of the load that is being placed on the bearing pivot is called a radial load. This load is a side load, or twisting load trying to force the pivot apart. A standard 608 skateboard bearing has a radial load rating of 304lbs. The MAX type bearing of the same size has a radial load rating of 505lbs or 40% more capacity. The MAX type bearing is designed for this pivot application and is inherently stronger, due solely to its higher ball count. This concept of the MAX type bearing has been used for many years in heavy equipment such as forklifts where rotational speed is minimal but where radial loads are high.

Bearing myth: Quote by suspension bike maker that does not use bearings:

Since sealed bearings in a suspension pivot never make a full rotation, the load is consistently resting on 2 to 3 balls within the race. Ultimately, those bearings become ovalized from wear, and suspension performance quickly deteriorates.
The above is an untrue statement.

If the myth above were true then many automobiles and motorcycles that use cartridge type bearings in suspension components would have similar problems to what is stated above, they simply do not.

The balls used in a cartridge bearing are typically 66-68 Rockwell hardness compared to the bearing race at 60-64 Rockwell hardness. The physics dictates the bearing race will wear before the balls will wear and ovalize.

While the weight of the bike and rider does rest on the lower balls, that weight is spread across 5 to 6 balls per cartridge bearing and across up to 8 bearings per frame. The load resting on the balls is not significant enough to cause the wear mentioned in the above statement.

Most of the load that is being placed on a bicycle suspension pivot is called radial load, this load is a side or twisting load. This radial twisting load is many times greater than the gravitational load described above.

If the above data does not help or your have additional questions please call Intense Cycles @ (951) 296-9596 press 3 for sales, Or send mail to [email protected]

Thank you for reading.
n10’sGuy
 
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