A recumbent bicycle includes a boom that telescopes within one end of a center tube in the main frame of the bicycle, and a boom clamp that encircles the center tube of the main frame at a location overlying at least a portion of the boom. The boom clamp has a locator tab which extends into a notch formed in the center tube, and within a slot formed in the boom while the boom telescopes within the center tube. The location of the slot in the boom, and the location of the tab relative to the center tube, are chosen to ensure that throughout the telescoping movement of the boom it is retained in a desired orientation with respect to the main frame.