Others have a guide rail screwed to the door (pictured above). Unscrew the guide at the lower edge of the sliding door.

Mechanical self-closing system for sliding pocket door system from ECLISSE functions so that once opened a door closes automatically. Thanks to the extractable track, an ECLISSE patent ...

RABEL 62 Slim Super thermal sliding door from Rabel Systems is a slim system ... with an integrated drainage channel which allows the track to be fully recessed into the floor while increasing ...