About a week ago (about 30 miles of riding ago) I noticed a very slight ticking sound when I applied the brakes. I noticed no decrease in braking power. Very suddenly this past Saturday the slight infrequent ticking noise became a constant loud handle shaking noise and the braking was seriously diminished. It took a while to notice that all but one of the six bolts that hold the disk to the right wheel had fallen out. The one remaining bolt had become loose, so the disk was now offset and clunking into the brake housing. Bolts on the opposite side are nice and tight. It says a lot that just one bolt held the disk tightly enough that the missing bolts caused no problem. But how did all but one get loose and fall out when none have a problem on the other side?