Stuurbuis

Stuurbuis, literally meaning “steerer tube” in Dutch, is the steering tube of a bicycle fork. It is the cylindrical component that passes through the head tube and is clamped by the headset to connect the fork to the frame. The steerer tube provides the mounting point for the stem and handlebars and houses the bearings of the headset, allowing the fork to rotate smoothly.

Materials and configurations vary. Common materials are steel, aluminum, and carbon fiber, chosen for strength, weight, and stiffness. The diameter and form depend on the headset type: the most widespread is a straight steerer tube of 1 1/8 inches (28.6 mm) used with threadless headsets; some forks use a 1 1/2 inch lower diameter in a tapered configuration. BMX and older designs may use 1 inch. Steerer tubes can be straight or tapered and may be threaded (for quill stems) or threadless (clamped by a stem). The length of the steerer must accommodate the frame’s head tube height plus stack height from spacers and the stem, and is usually cut to length before final assembly.

Installation and maintenance require compatibility among the steerer, headset, and stem. Cutting carbon steerer tubes should be done carefully, with proper protection and tooling. Regular inspection for cracks or damage is advised, especially after impacts. Proper torques on the stem and correct spacers ensure safe steering performance.

In summary, the stuurbuis is a central component of the bicycle’s steering system, with variations in diameter, length, material, and headset compatibility that influence fit, stiffness, and handling.