Coupling mechanism for use with a roller tube of a window treatment

A motorized window treatment system comprising:

• a roller tube having a smooth inner surface;
• a drive assembly for rotating the roller tube, wherein the drive assembly is at least partially received in the roller tube;
• and
• a coupling disposed between the roller tube and the drive assembly for transferring rotational motion of the drive assembly to the roller tube, the coupling comprising:
• a central bore extending therethrough along a rotational axis;
• a ring having a first diameter, the ring having a plurality of notches for engaging the drive assembly;
• an outer flange having a second diameter that is greater than the first diameter, the outer flange defining a cavity recessed from an outer surface of the outer flange;
• and
• a spring clip retained in the cavity, the spring clip comprising a base disposed in the cavity and first and second compliant members extending from the base at a respective angles to engage the inner surface of the roller tube such that relative rotation of the coupling with respect to the roller tube is prevented.