Brake Squeak

[TownsendsFJR1300]

The first pic, the nub, I'm not sure where it is but does it appear to "do anything", just a casting mark, etc?

What rubbed off the finish of it?? Kinda odd, does it appear to have been rubbed by something/is there anything adjacent to it to wear it down?

The second pic looks good on the "outside" space wise... Is it clear or roughly centered over the disc on the other side as well?
IE, the disc is in the middle of the bracket?

 

[upshiftoverdrive]

The nub is by the front caliper bolt on the disc side. The only thing it could have rubbed on was the disc. It kinda makes sense since the front caliper bolt is just a slide right? It doesn't seem to thread into the caliper mount, it just slides in and threads in the actual caliper. So somehow the nub was rubbing on the disc and vibrating for a short length every rotation. Could be that my disc is warped maybe? Already have the bike reassembled or else I would check.

So anyways, I ground the nub almost flush with the caliper mounting plate and it seems to have taken care of the sound. I also surfaced the pads which could have been the problem ultimately. A unevenly worn pad maybe? I find it hard to believe that a metal nub rubbing against the disc could create that vibrating sound, seems like it would be more of a screeching sound.

It seems fixed for now. Pumping the brake and backing up, it's quiet. The real test will be after a ride, it would always be really loud backing up then. I guess because of the metal heating up and expanding.

Warped rotor?

Also, if you guys hop on your bike and roll it forward with a bit of momentum and jam the rear brake to lock, does the caliper make a click sound as the tab shifts in its slot? (Or rather the slot shifting over the tab) and then if I roll the bike back and jam the brake, the caliper shifts the other way and makes a click as the tab hits the other side of the slot. I am wondering how close of a fit those are supposed to be and if my tab-slot relationship is a little bit loose?

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[TownsendsFJR1300]

The anti rattle plates should be taking up any clicking when braking slowly and apply brakes. I don't get any clicking or squeaking,

To warp the rotor, you have to be VERY HARD on it (racing, or super hot, then ride thru a water puddle). Rotating the rotor with the tip of a screwdriver
to the surface (unless you have a dial gauge) will show, especially how bad your noise is/was. IE, I seriously doubt that's your issue.

As noted earlier, it only takes one person to tighten and bend that main bracket if not installed in the slot. I've done it before (but caught it BEFORE I tightened).
My money is on the bracket being bent slightly. Yamaha doesn't give much room in there for bent parts...

 

[upshiftoverdrive]

So it was good for awhile. Now it is back to squeaking.

I will check on the rotor being warped, but like you said, it is unlikely that is the problem.

After 'resurfacing' the pads on some concrete the brakes didn't squeak for a few rides. The brake feel was squishier, now that it has firmed up again, the brakes are back to squeaking.

I am confident it is the pads that are making the noise, I am not sure why they are doing it though.

I had the bike on the center stand and spun the wheel = Faint squeal
Pumped the brakes and spun the wheel = Loud squeal
Sprayed a spritz of water directly on the pads and spun the wheel before it could drip on anything = Silence

The squealing only occurs when the wheel rotates backwards? Weird isn't it?

Is something making the pads wear weird? Because when I had just resurfaced the pads, they were completely silent.

 

[TownsendsFJR1300]

The two rubber, accoridan looking boots, the rear caliper floats on the bolts.

Have you ever cleaned the old grease out of there and re-greased with brake grease?

I seriously doubt that's your issue but they should be serviced in any event...

 

[upshiftoverdrive]

They're pretty dry actually.

The boot close to the front of the bike has a small hole in it. Not sure if that is grounds to replace or not.

I will re-grease them and surface the pads again I guess....

 

[TownsendsFJR1300]

The brake caliper centers itself on those two bolts..

If their sticking, you'll get un-even wear, not the noise thou.

If the holes not too big, get a new boot next time you order something.

But, clean those boots out good, and the shaft, bolt it rides on and don't be cheap with BRAKE GREASE.

 

[FinalImpact]

Honestly it sounds like the antirattle clips are either not applying enough tension or there are large enough groves in the rotor to turn it into a record of a sense.

In short, when spun forward, like when braking the pads take one set in one orbit. When spun backwards, the groves shared by rotor and pad are in a different orbit as the pad moves so the tiny groves in the pads are like the needles of a record player and they squeal. Its why your scuffed pads don't squeak.

Why is yours different? OEM pads or no?
Perhaps bend the rattle clip so it applies more down force on the pads?

 

[upshiftoverdrive]

Honestly it sounds like the antirattle clips are either not applying enough tension or there are large enough groves in the rotor to turn it into a record of a sense.

In short, when spun forward, like when braking the pads take one set in one orbit. When spun backwards, the groves shared by rotor and pad are in a different orbit as the pad moves so the tiny groves in the pads are like the needles of a record player and they squeal. Its why your scuffed pads don't squeak.

Why is yours different? OEM pads or no?
Perhaps bend the rattle clip so it applies more down force on the pads?

This theory sounds plausible... I like it.

I do not have original pads, I have on Volar Kevlar pads.

When you say anti rattle clips, are you talking about this? Imgur: The most awesome images on the Internet

 

[FinalImpact]

Item #8 here....
OK so different pads. Now you get into potential for material mismatches.... pad to hard for disc...

Ever notice early German cages ate rotors and squealed? Like 3 rotors and one pad set? Same thing...