Sunlite Steel Pillar Seat Post - 28.6 x 14 (For Trikes) Sun Bicycles Sun Trike Replacement Seatpost - 14 x 28.6 mm, X-Long, CP - 51711 SEATPOST SUN TRIKE REP 14x28.6mm X-LONG CP 14 Steel Trike Seatpost (28.6mm O.D.)