Had this squeek from the rear but only happened on sharp bumps like when going over the refectors on the road. I checked all bushes, bolts and springs and no change so i gave up on it. Today while changing the rear pads in bumped the disc and i heard the exact same squeek!! it ended up being the inner of the disc where it meets the axle flange. I removed the disc and applied a small amount of grease and no more squeek!! i only found the root cause by accident and i would never expected it to be that. Hope this find helps others.

I did the same to mine about 8 months ago, rear end is great.!
But the front has caliper slap :/ so I get the same noise at the front!

Great find!!, ive got this squeek also! ive been everywhere and no one can find what it is, i will try this today.