An improvement in the method of securing tubes that support the seat back to the frame of the bicycle. The device is a clamp that holds the two tubes in place with bolts. This method of clamping the tubes allows the seat to be easily adjusted in any increment desired to accommodate a user of any size. It also obviates the use of pins and will save the setting of the placement of the seat, even after the seat is removed. The clamp is secured onto the small tube at a position desirable to the user and the large tube is placed over the small tube. The bolts are then tightened to lock the clamp into place. The invention applies to any bicycle and is a unique improvement on the existing methods of adjusting the height of the seat.