An assembly for a drug delivery device (1), comprises a housing (2), a dose member (22), a guide track (42) and a spring member (26). The dose member (22) is adapted to be rotated in a dose setting direction with respect to the housing (2) for setting a dose of a drug (5) and to be rotated in a dose delivery direction with respect to the housing (2) for delivering the set dose. The dose member (22) comprises a guide feature (46). The guide track (42) is configured to mechanically cooperate with the guide feature (46). The guide track (42) comprises a first section (43A) and a second section (43B) which are connected to each other via a connection region (55). The first section (43A) defines an angular start position (54) for the guide feature (46) and the second section (43B) defines an axial stop position (56) for the guide feature (46). When the dose member (22) is rotated in the dose setting direction, the guide feature (46) is angularly displaced from the angular start position (54) towards the connection region (55), the spring member (26) is torsionally biased, the biased spring member (26) tending to angularly displace the guide feature (46) towards the angular start position (54). When the guide feature (46) has passed the connection region (55), the guide feature (46) enters the second section (43B) and is axially displaced in a proximal direction with respect to the housing (2) towards the axial stop position (56). In the axial stop position, reduction of the torsional bias is prevented by mechanical cooperation of the guide feature (46) and the second section (43B).
