Bicycle Parts Wholesale

The stem is the component on a bicycle that connects the handlebars to the steerer tube of the bicycle fork. Sometimes called a goose neck, a stem's design belongs to either a quill or threadless system, and each system is only compatible with the respective headset and fork designs:

The quill stem inserts into the steerer tube which is threaded and does not extend above the headset.
The threadless stem clamps around the steerer tube which is not threaded and which extends above the headset.