Abstract: A telescopic mechanism includes a top tube, a bottom tube, a supporting tube, at least one stroke tube, at least one first positioning tube, at least one second positioning tube, and a control assembly. The bottom tube is slidably disposed around the top tube. The supporting tube is disposed in the top tube. The at least one first positioning tube and the at least one second positioning tube are disposed in the top tube. The control assembly is connected to the bottom tube and has a positioning base. The positioning base is movably disposed in the at least one stroke tube, the at least one first positioning tube, and the at least one second positioning tube. When the positioning base is fastened with the at least one first positioning tube, the top tube is moved toward a first direction relative to the bottom tube to form a first length.

Abstract: A seat post has an axis direction and includes a lower tube, a gas cylinder, an upper tube, a first stop element, a travel spacer and a second stop element. The lower tube includes a lower tube inner surface, an accommodating space and an opening. The lower tube inner surface forms the accommodating space and includes a lower overlap area. The upper tube includes an upper tube outer surface, which includes an upper overlap area. The upper tube is movably sleeved on an outside of the gas cylinder along the axis direction and disposed on an inside of the lower overlap area. The travel spacer is disposed between the upper overlap area and the lower overlap area. The first stop element, the travel spacer and the second stop element are arranged in sequence along an elongation direction from the accommodating space to the opening.

Abstract: A telescopic mechanism includes a top tube, a bottom tube, a supporting tube, at least one stroke tube, at least one first positioning tube, at least one second positioning tube, and a control assembly. The bottom tube is slidably disposed around the top tube. The supporting tube is disposed in the top tube. The at least one first positioning tube and the at least one second positioning tube are disposed in the top tube. The control assembly is connected to the bottom tube and has a positioning base. The positioning base is movably disposed in the at least one stroke tube, the at least one first positioning tube, and the at least one second positioning tube. When the positioning base is fastened with the at least one first positioning tube, the top tube is moved toward a first direction relative to the bottom tube to form a first length.