# rear wheel bearings keep coming loose



## Guest (Dec 21, 2012)

I have a focus fitness bike I bought last year. Its a great bike for winter riding. About every 500 miles or so the rear wheel gets wobblely. I have to tighten the bearing down to fix it but it doesnt last. I cannot tighten it too tight or the wheel will not spin freely. The bike has disk brakes, I dont know if this is common with disk brake bikes. I am considering buying some new wheels or would new bearing unit be better? any advice


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## JCavilia (Sep 12, 2005)

What kind of bearings are they? A bearing won't loosen if it's adjusted properly. There should be a part (usually called a "cone") that you move to adjust the bearing pre-load, and another part -- a locknut -- that you tignten against the cone so it doesn't move. Sometimes this requires the use of thin open-end wrenches -- known as "cone wrenches." It sounds like you may be just turning the cone and locknut together, without tightening them against one another after adjustment.

Check the Park Tools website for more detailed discussion.


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## PJ352 (Dec 5, 2007)

Agree that we need more info... the year, model of your Focus and/ or any markings on the hubs/ rims. 

JC described cup/ cone (loose ball bearing) type hubs. There are also cartridge bearings that may or may or be adjustable, depending on model. The ones that aren't generally are replaced when play develops.


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## Guest (Dec 21, 2012)

yes you are right it isnt the bearing thats loose its the lock nut that keeps coming loose. I have a set of the wrenches you are talking about and when I have to tighten the lock nut I have make sure the other side isnt turning. It just doesnt stay tight. thanks for the info!


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## Kerry Irons (Feb 25, 2002)

jm59 said:


> yes you are right it isnt the bearing thats loose its the lock nut that keeps coming loose. I have a set of the wrenches you are talking about and when I have to tighten the lock nut I have make sure the other side isnt turning. It just doesnt stay tight. thanks for the info!


Only guessing here because you are being quite imprecise in your description but it sounds like you are trying to hold the two locknuts (one on each side of the hub) and if this is the case, you're doing it wrong. You need to properly adjust the cones and then tighten the cones against the lock nuts. Probably the right side cone and lock nut are tight against each other already and you can't get at the cone without removing the axle. If it is the right side (cassette side) of the hub that is loosening then you will need to remove the axle and firmly tighten that cone against its lock nut. Then do the other side once the hub is reassembled and properly adjusted.


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