hi..... after two weeks or so of having arranged my brake sqeal (Avid Arch Rival 5's gripping on MavicX512's) i've got this misterious thud on every revolution of the rear wheel. It does not happen unless I brake hard on a downhill at around 30KM or over, so I cannot locate the exact position where the thud is. I examined the rim thoroughly - no defects - I cleaned it but still.

any ideas anyone ??

cheers

claude