A seatpost assembly having: a first seatpost portion and a second seatpost portion, where the second seatpost portion is axially displaceable relative to the first seatpost portion in retracting and extending directions and is configured to include a seating surface; a motive force transmitted by a control rod to drive the axial displacement in at least one of the extending and retracting directions. The motive force is actuated remotely from the seatpost assembly.