The present disclosure relates to a cross bar for a vehicle article carrier that may be releasably secured to a support rail. The cross bar has an end support at each end thereof for securing the cross bar to the support rail. Each end support has a main body configured to engage with a portion of the support rail, an opening in the main body, and a latching element moveably supported from the main body. A threaded member is used for controlling engagement of the latching member with the support rail. The threaded member has a head portion which engages with portions of a spring clip secured in the opening. This helps prevent loosening of the threaded member after it has been tightened.