
A swing arm is disclosed including a bottom curved tube, which has a first fitting with an inward bottom staking step and a second fitting with an inside chamber respectively at two opposite ends, a top straight tube, which has a first fitting with an inward bottom staking step and a second fitting with an external stop knob respectively formed at two opposite ends, and a connecting device to connect the first fitting of the top straight tube to the first fitting of the bottom curved tube throug...











