So I've got brake squeal coming from the back wheel while the bike is rolling and the rear brake pedal is not depressed.   

You expect a bit of that famous GS rear brake squeal when using the rear brakes, but I didn't expect it without using them.

Any thoughts?

When I examined the rear pads, it appears that they sit right on the disc at rest.  Is that normal?

They may appear that way, but they shouldn't touch.

How's your brake fluid?

What color is it?

When was it last changed?

Is the axle tight?

Are either of the chain adjusters loose?

Quote from: scratch on June 14, 2006, 04:47:17 PM
They may appear that way, but they shouldn't touch.

How's your brake fluid?

What color is it?

When was it last changed?

Is the axle tight?

Are either of the chain adjusters loose?

Hey Scratch,

The brake fluid is within the high-low lines.  As I recall it is a golden colour.  It was replaced in late March (2000 km ago)

The axle is tight (47 foot-lbs).  I know this because I tightened my chain 2 nights ago and used a torque wrench on the axle nut.

The chain adjusters were fine when I tightened the chain, but I'll have to recheck those.  When tightening those chain adjustment nuts, you tighten them the same amount and in the same direction right?

It does seem an interesting coincidence that this starts happening after I tightened my chain, but then I only noticed this was happening because my wife heard it when I was riding by.  It's possible it's been making this noise for a while 

Put her in neutral and on the centerstand and try to rotate the rear wheel. You should not feel any substantial drag.

I have a suspiciaon that your rear brake cylinder is somehow stuck or obstructed in its inward movement, and that through your chain adjustment you have slightly skewed your rear wheel. (It doesn't have to be a lot to result in dragging ig the brake caliper won't open freely.)

Quote from: MarkusN on June 15, 2006, 05:56:39 AM
Put her in neutral and on the centerstand and try to rotate the rear wheel. You should not feel any substantial drag.

I have a suspiciaon that your rear brake cylinder is somehow stuck or obstructed in its inward movement, and that through your chain adjustment you have slightly skewed your rear wheel. (It doesn't have to be a lot to result in dragging ig the brake caliper won't open freely.)

I did try this, and decided that the rear wheel wasn't turning as freely as the front, but then there is also the drag of the chain and front sprocket so I deemed my test inconclusive.

Quote from: daneilah on June 15, 2006, 05:00:43 AM
When tightening those chain adjustment nuts, you tighten them the same amount and in the same direction right?

Yes.

Quote from: daneilah on June 15, 2006, 05:00:43 AM
It does seem an interesting coincidence that this starts happening after I tightened my chain, but then I only noticed this was happening because my wife heard it when I was riding by.  It's possible it's been making this noise for a while 

But, you didn't notice squealing?

Was it shushing instead; y'know, going shush, shush, shush?

Spinning it forwards or backwards?

Quote from: scratch on June 15, 2006, 06:49:02 AM
But, you didn't notice squealing?

Was it shushing instead; y'know, going shush, shush, shush?

Spinning it forwards or backwards?

I didn't notice it at all.  My wife was at the mailbox, I rode by.  She comes back to the garage and says, your bike is squealing.  I guess when you're riding you've got the helmet on, the engine is revving, etc. etc.

I didn't hear it 'til I put it up on the center stand and let it idle in first gear. 

Tonight when I'm checking the alignment, I'll also spin the wheel backwards and forwards and try and describe the sound.

Rear wheel alignment could be off too... 

So tonight I tried adjusting the alignment of the wheel to solve the squealing.  Using all forms of measurement suggested on this forum, my wheel appeared to be in good alignment.  So I messed with it anyway.  Got it way out of alignment, then managed to get back in alignment without the squealing.... score!  Checked the chain tension.... too tight.... crap!

Adjusted the chain again, appeared to still be in alignment, started squealing again.... double crap.

So while it appears that the squealing is the result of my own actions , I still haven't got the combination of no squealing and the correct chain tension

Gave up for today... I'll give it another go tomorrow.   Sigh.

Well, at least you're on the right track.