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Discussion Starter · #1 ·
:confused:Need some help...

Noticed a few days ago the the rear wheel on my 2004 Sprint ST squeals when rotated when on the centerstand. Happens even at very slow rotation and occurs throughout the wheel's rotation. There doesn't seem to be any additional resistance to the wheel spinning, just the squealing which seems to come from behind the rear sprocket.

After troubleshooting, I found that the squeal only exists when the chain adjustment pinch bolt is torqued all the way down. If I loosen it a turn or two, the squeal is gone.

So, any ideas what could be causing the squeal when the pinch bolt is tight? I've never removed the rear wheel myself, so I've never seen the arrangement of bearings, etc inside.

Thanks in advance

AZTriple
 

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+1 on Dave, it sounds like you have a bearing problem in the eccentric hub, I really wouldn't ride it till it's sorted out. They are known to break up and seize the rear wheel when they fail fully, and take the rear axle with them. Don't take any chances.

Here's a picture

There's a double ball race on the left nearest the sprocket, and a needle roller on the right on the axle shaft.
 

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When was the last time the rear hub bearing was lubricated? It is supposed to be done at 6k intervals, my guess it has not. As others stated....DO NOT RIDE THIS BIKE. Tow it to your local dealer or mechanic.
 

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how about taking the rear caliper off and checking if it still squeels? If so, then pull the wheel, and the shaft and do the bearings. There's an excellent write up on how to do the rear bearings in the maintenance tips and tricks section.
 

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+1 on what Charlie said!
Check for brake drag/squeal before you get carried away with this.
You can probably reach thru the wheel spokes and twist the caliper to and fro by hand in order to get some pad clearance.
 

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Discussion Starter · #11 ·
I can rule out the brakes. That's the first thing I checked in fact. I removed the caliper with no change in sound.

Chain was my next guess. I over-lubed it adjusted it. The squeal occurs at all chain tensions when the pinch bolt is tight.

Like I said, just loosening the pinch bolt slightly makes the noise stop dramatically. I tried to clean the area between the eccentric adjuster and sprocket in case some debris was causing it, with no change.

It must be something inside that is getting squeezed when the bolt is torqued down that last little bit.

The only other thing is that if I apply a side load to wheel while spinning it, it slightly changes the noise. Also, if I spin the wheel as fast as I can by hand, it also seems a little quieter.

Bearings seem to be possible, but I expected more of a grinding sound rather than squeal.

I agree with all the suggestions to not ride it. It's going to stay put until I get the wheel off and find the issue.
 

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Squealing often precedes grinding. In fact, squealing might be considered to be high frequency grinding? Any acoustical experts here?

Previous posters offered good advice. Prudent to heed them.
 

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sound like his balls are dragging. :D painful.

Seriously though, from the description, it's a roller or one of the deep grove ball bearings that's skidding/flat spotted.
 

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Discussion Starter · #14 ·
Dragging Balls? Ouch, not sure my health insurance covers that!

Thanks for all the input and advice. The wheel comes off as soon as I buy a large enough socket. I'll report back with what I find.
 

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Don't strip too much off the bike. You will most likely need the wheel on and in contact with the ground, the brake on and operational in order to get both axle shaft nuts loose!!!!!
 

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Discussion Starter · #18 ·
Don't strip too much off the bike. You will most likely need the wheel on and in contact with the ground, the brake on and operational in order to get both axle shaft nuts loose!!!!!
Thanks, the brake went back on as soon as I ruled it out, but I can imagine doing something like that :)
 

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Discussion Starter · #19 ·
After removing the wheel, I have found that the needle bearing was dry with no trace of grease.
The bearing itself did not appear damaged, though it will be replaced soon. I did grease it and reinstalled it to see if that would resolve the squeal issue, which it has.
To answer the obvious next question, it is possible that it has not been greased in over 20k miles. This was not a service item when the bike was new. I don't know if it was done at 6k miles, but I do the majority of maintenance now, and the bearing lubrication fell through the cracks....

So, that bearing is definitely not something to neglect.
 

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Close call AZTriple

Well................

I would say that was a good save as it would not have been very nice had the bearing decided it was to hot and bothered and didn't want to play anymore!

cheers
DaveM:)
 
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