Originally Posted by
Andrew R Stewart
This is likely the rim's joint plug that's broken loose. Many Mavic rims have this noise. Not quite the same as might be plaguing the OP but an object in the rim just the same. Some have driven self taping screws or dripped glues into these mavic rims to quiet the plugs. Andy
I'm pretty sure this rim has a welded seam since the sidewalls/brake tracks were machined so
AFAIK there aren't any alignment dowels.