# Possible Rear Wheel Problem? Cassette Moving.



## jonshonda (Apr 21, 2011)

Hello all, 

First of all I would like to say thanks!! I purchased a used 09 Specialized RH Comp 29er from my LBS after reading so many great things about them here!! I am addicted to the Specialized thread. :thumbsup: 

I went for a ride tonight, had a great time, found some mud!! Anywho, put it up on the bench tonight to inspect and clean, and am seeing something I find to be odd. I pedal the bike (front and rear cassette in middle gears) and then stop, letting the rear wheel spin. As I am watching the rear wheel spin, I am looking directly at the rear cassette (eye level with rear axle) and am seeing the cassette moving up and down a little. It is not concentric with the movement of the wheel, meaning its path is more oblong than circular. 

It appears that the axle or hub is bent? I know the wheels don't get the best remarks, and I am a overweight clyde. My first two rides have not been a walk in the park for the bike.


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## markf (Jan 17, 2007)

probably normal. did everything shift and roll okay? a little tiny wiggle is fine.


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## jonshonda (Apr 21, 2011)

Yup, everything shifts and rolls fine!! The movement is enough that is transfers through the chain, and it is easy to see the front crank/pedals moving back and forth.


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## mack_turtle (Jan 6, 2009)

sounds normal actually. does the cassette wiggle side-to-side on the freehub? if so, it needs to be tightened or it needs a spacer. otherwise, it should be free to float a little.


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## jonshonda (Apr 21, 2011)

I think its side to side motion is fine...it just looked like something was not right when seeing the cassette moving around.


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## kapusta (Jan 17, 2004)

jonshonda said:


> Hello all,
> 
> First of all I would like to say thanks!! I purchased a used 09 Specialized RH Comp 29er from my LBS after reading so many great things about them here!! I am addicted to the Specialized thread. :thumbsup:
> 
> ...


So you are saying that when the wheel is spinning, but the cassette is not (such as when coasting) the cassette is moving up and down?

How much it is moving? Is it the whole cassette, or just curtain cogs? Are you certain it is not moving in a circle?

Does not sound right to me. I do not think this is normal.


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## ProjectDan35 (Jul 19, 2010)

It's normal. Does it to my bike ( up and down kind of motion), even when new! It's 9months old now. Doesn't affect any shifting either.


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## jonshonda (Apr 21, 2011)

kapusta said:


> So you are saying that when the wheel is spinning, but the cassette is not (such as when coasting) the cassette is moving up and down?


Yup



kapusta said:


> How much it is moving? Is it the whole cassette, or just curtain cogs? Are you certain it is not moving in a circle?


The whole cassette is moving about 1/32" in both directions. It is def not in a cirucular pattern...very much oblong.



kapusta said:


> Does not sound right to me. I do not think this is normal.


I have been told it cold be the free hub body? Not a big deal, just wondering what it was.


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## jeffj (Jan 13, 2004)

Sounds like the axle may be slightly tweaked which would put the inner bearing races not quite square with the bearing cones or maybe a slightly tweaked freehub fixing bolt. Regardless of the actual cause, I see it on a lot of bikes. If it's just a tiny bit of movement, I wouldn't stress on it.


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## jonshonda (Apr 21, 2011)

I appreciate the help....and will continue to ride until something breaks!! I just wanted to make sure this "little" issue wouldn't lead to bigger issues.


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## Kaizer (Jul 19, 2010)

A friend has the exect same problem, but it's affecting the shifting performance. Have a look at the freehub.


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## jonshonda (Apr 21, 2011)

Went to the LBS where I bought the bike...and dispite me willing to spend money on a nicer wheelset/freehub, the owner told me it is pretty common. An issue that most bikes have to some degree or another. If there are no shifting problems, leave it alone.


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## jalopy jockey (Jun 7, 2007)

jeffj said:


> Sounds like the axle may be slightly tweaked which would put the inner bearing races not quite square with the bearing cones or maybe a slightly tweaked freehub fixing bolt. Regardless of the actual cause, I see it on a lot of bikes. If it's just a tiny bit of movement, I wouldn't stress on it.


I agree but in the case of my wife's bike it was bad enough that she had the axle replaced. Then she replaced the bike cause she realised it was no longer up to her standards.


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## Timeless (Mar 23, 2007)

It did it on my rockhopper when I got it as well.Nice to know it is fairly common.


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## shiggy (Dec 19, 1998)

jonshonda said:


> Went to the LBS where I bought the bike...and dispite me willing to spend money on a nicer wheelset/freehub, the owner told me it is pretty common. An issue that most bikes have to some degree or another. If there are no shifting problems, leave it alone.


Just check that the FH body is tight on the hub shell.

Not uncommon for a hub/FH not to be concentric and wobble a bit.

It is not a bent axle, which can not cause a wobble as the axle is fixed to the frame does not turn.


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