I have a Topeak Super Tourist DX rack and an MTX TrunkBag DX bag, which fit together using Topeak's QuickTrack system - a dovetailed plastic foot on the bag slides into a metal channel on the rack.
Both are several years old. Recently, the combination has developed a wobble, where the bag seems to be able to move from side to side in the rack. The bag doesn't fall off, but the noise is annoying!
What causes this? Is the plastic foot worn, or is the metal channel bent?
Is there a cure for it, apart from replacing one or both parts?