Abstract: A treadmill includes a base and two posts are connected to the two side rails. A frame with an endless belt is pivotably connected between the two posts. Each post has an elongate hole and two sets of pivot assemblies respectively extend through the two elongate holes. Each pivot assembly has a pin and a roller which is mounted to the pin which is fixed to the frame. The roller is movably retained in the elongate hole corresponding thereto. A support device has an end fixed to the base and the other end of the support device is pivotably connected to an underside of the frame. The frame is pivoted upward about the pins and the rollers assist the pivotal movement of the frame. The pins are moved within the elongate holes to adjust the inclination of the frame relative to the base.

Abstract: A treadmill includes a base with two side rails and two posts with two handles are connected to the two side rails. Two guide members are connected to the two side rails and each guide member has two curve grooves which are located symmetrically about a diameter of the guide member corresponding thereto and share a common center. A frame with an endless belt is pivotably connected between the two side rails and two pin sets are respectively connected to each of two sides of a first end of the frame and movably engaged with the two curve grooves of respective one of the two guide members. Each pin set includes a bearing movably received in the curve groove so that the frame is easily pivoted by moving the pin sets in the curve grooves.