A thumbstick for a user input device comprises an adjustable tensioning mechanism configured to modify a tilt tension of a tiltable post. The thumbstick comprises a cap with a cylindrical stem that defines a first cavity. Abase is moveable with the tiltable post and comprises a cylindrical portion extending into the first cavity. The cylindrical portion defines a second cavity and comprises a protuberance projecting into the second cavity. An adjustment body within the second cavity comprises a recessed slot and a contacting surface at a distal end. The slot is configured to engage the protuberance to adjust the tilt tension of the tiltable post.