Adjustable and foldable stem and bearings for wheeled vehicles

摘要

A steering assembly for connecting the front wheel and handlebar of a bicycle or other wheeled vehicle to the frame. A steerer tube is connected to the front wheel and passing through a head tube on the frame. A stem connects the steerer tube to the handlebar, and bearings on the top and bottom of the head tube which allow the steerer tube to pivot axially inside the head tube. The top of the steerer tube extends above the bearings and is slotted and fitted with a quick release clamping device which allows the stem to be raised and lowered inside the steerer tube. The sides of the stem are channeled such that the stem cannot rotate axially inside the steerer tube and the upper portion of the stem can be lifted out of the steerer tube, then rotated, and folded down to the side of the bicycle frame during storage. The headset bearings are either threaded to the steerer tube or threadless and held in place by an expanding mechanism which pushes upward on the bottom of the quick release mechanism and downward on the bearings.