Frame front fork drop tester

The machine should be able to rotate freely on the vertical plane centered on the rear axle mounting point, the front fork is supported on a flat iron, so that the frame is in the normal position, and a 70kg counterweight is fixed on the straight tube of the seat cushion. Place the straight tube of the seat cushion so that the center of gravity falls on the axis of the straight tube and is 75mm higher than the surface of the horizontal tube of the seat cushion, and measured from the axis of the horizontal tube, rotate the frame assembly to make the center of gravity of the counterweight turn to the vertical of the rear axle Just above, and then let the frame fall forward freely and hit the iron on top, and repeat the test to obtain two impacts.