The majority of modern road bikes use threadless 'Ahead' stems, which mount directly to the steerer tube for a stiff, stable connection. Most stems are aluminium, although some high-end models are carbon. A removable front plate makes it easy to (de)mount the handlebars without removing the shift and brake levers. When choosing a stem, check whether it fits your handlebars: some have a diameter of 26 mm but most are 31.8 mm. Please pay attention to the length and angle of the stem to make sure it provides the position you want. Remember that a stem can be also flipped to give a negative angle.