The place to come to share your technical expertise, or just find out what the little springy thing is that's just pinged out of sight under the work-bench.
To test for warped brake discs, use a black white board marker & draw a wavey line over the surface of the swept area . Then rotate the wheel & see where the black line is rubbed off
Quick check. The discs are floaters so the disc bobbins should rotate (reasonably) freely. If they don't, get to work with paraffin and a toothbrush to clean them up. Solved the problem on my RU.
