# Slight rear wheel wobble + brakes rubbing



## garcont (Apr 28, 2016)

My mechanic knowledge is extremely limited so I am looking for help and suggestions.

The last two times I was out riding, in the middle of my ride I would start hearing a squeal coming from (I think) my rear brakes just while pedaling (not applying any pressure to brakes).

I re-aligned rotor and caliper and made sure brake pistons were completely reset and all was well again.

The next ride, same thing happened. Middle of the ride brakes started rubbing pretty bad again. I also noticed that I have a slight wobble in my rear wheel and I am wondering if these two issues are related.

I do NOT notice any side to side play when I grab the rear wheel.
In similar posts it seems like the answers typically point to bad or loose bearings, but they also usually indicate there is some play in the wheel. 

Do loose bearings seem like a likely culprit?
If so, how do I access and adjust them? 
Other potential causes?

I do not know the exact hub on my bike, but according to the specs it has sealed cartridge bearings.
Axle is a 12 mm thru axle.
Bike is practically new so nothing should be worn.
I removed the cassette, but could not really see where to go from there.


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## jacksonlui (Aug 15, 2015)

Did you make sure your thru axle was tight and didnt come loose during the ride?


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## Cleared2land (Aug 31, 2012)

You have a thru axle, so there is no issue with 'loose bearings' or any adjustment. As stated above, ensure that your thru axle is sufficiently tight.

A wobble in your wheel will have no impact on the hub or brake rotor unless the thru axle is loose. 

It sounds as if you have taken the appropriate measures to correct your issue. How are you going about 're-aligning' the rotor and the caliper?


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## LyNx (Oct 26, 2004)

Take it back to the shop you bought it from, let them deal with it, that's why you buy from a local brick and motor shop and not the internet. If you didn't buy it from a local shop, then find a good one and take it to them, as sounds like you've done your best to try to figure it out. You never mentioned what the brakes were and if they were PM or IS mount. 
Despite having great respect for C2L, he is wrong, doesn't matter what axle configuration you have, if you have lose bearings, it can allow the entire hub to wobble, the disc rotor is attached to the hub, hence it can cause it to wobble also and cause rub. It does sound however like you've eliminate bearing play with your test, more than likely you have a stuck/lazy piston, to check see if both pistons come out evenly after you reset them or if one is further out than the next - squeeze the lever gently to see this easier.



garcont said:


> My mechanic knowledge is extremely limited so I am looking for help and suggestions.The last two times I was out riding, in the middle of my ride I would start hearing a squeal coming from (I think) my rear brakes just while pedaling (not applying any pressure to brakes).
> 
> I re-aligned rotor and caliper and made sure brake pistons were completely reset and all was well again.
> ..................I do not know the exact hub on my bike, but according to the specs it has sealed cartridge bearings.
> ...


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## Cleared2land (Aug 31, 2012)

My point was making reference to loose bearings and the assumption that he had cartridge bearings (as stated) and therefore would not have a cup & cone that could need adjustment. So, aside from an un-true wheel (rim), my only thought that could cause the wheel to wobble would be a loose thru axle. 

I haven't seen cartridge bearings so worn that they are loose before. Conceptually, I guess that's possible, but in many many miles, bikes and years, I haven't seen that.


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## LyNx (Oct 26, 2004)

Remember, some cartridge bearing hubs actually use Angular Contact bearings which require pre-load to work properly and even hubs with normal raced bearings need to be secured so they cannot rock/move within the retaining area, so if they aren't secured tight/properly, they can move and cause the wheel to rock/move. I do bike service/repair and I've come across cartridge bearings hubbed wheels with this issue a few times before and with bearings so badly worn they caused the wheel to wobble and cause brake rub, happens when people don't do regular maintenance on their bikes and wash them with high pressure hoses and blow water into the bearings and then it goes from there.



Cleared2land said:


> My point was making reference to loose bearings and the assumption that he had cartridge bearings (as stated) and therefore would not have a cup & cone that could need adjustment. So, aside from an un-true wheel (rim), my only thought that could cause the wheel to wobble would be a loose thru axle.
> 
> I haven't seen cartridge bearings so worn that they are loose before. Conceptually, I guess that's possible, but in many many miles, bikes and years, I haven't seen that.


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## Cleared2land (Aug 31, 2012)

LyNx, you addressed a good point...I'm familiar with angular contact bearings, I've just never had any wheels that had them. So, as a result, I wasn't thinking about angulars being installed on hubs/wheels. All of my pivot bearings are angular and I fully understand how to dial them in and maintain them. 

Midgemagnet...wow! I must have been blessed by the bearing gods. I have managed to keep all of my wheel bearings rolling for many miles/years free of any problems or issues with simple maintenance and servicing. I have multiple wheel sets that have seen anywhere between 4,000 and 10,000+ miles with little more than regular service. I just replaced some I-9 front hub bearings because one of them was compromised by water and an improperly sealed end cap. That hub had just over 5,000 miles on those original bearings. The rear hub is still rolling just fine, but I did pop the seals and confirm that all was well.


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## jacksonlui (Aug 15, 2015)

What happens when angular bearings aren't preloaded? Do they not rotate properly? I have some but sometimes i wonder if its too much or too little preload, i figure it just needs some , enough to allow it to spin nicely. Sorry for digressing

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## Cleared2land (Aug 31, 2012)

jacksonlui said:


> What happens when angular bearings aren't preloaded? Do they not rotate properly? I have some but sometimes i wonder if its too much or too little preload, i figure it just needs some , enough to allow it to spin nicely. Sorry for digressing


If the pre-load is too loose, you'll have the issues as outlined by LyNx...too loose and possibly wobbly. Too tight of a pre-load and you can feel a 'notchy like' feel to the wheel that is a restriction to rotation. Properly 'dialing in' any angular or loose (cup & cone) bearing is a little bit of art. But when done correctly, it's super smooth.


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## jacksonlui (Aug 15, 2015)

Thx 

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## dundundata (May 15, 2009)

Are u getting all this my extremely limited mechanical knowledge friend?


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