Types of Bicycle Headsets Explained

Headsets provide a rotatable interface between a bike’s head tube and the fork steerer. Knowing what kind of headset system your bike uses is critical should you ever need to replace worn headset components.
 

Types of Headsets:

The headset is a bearing system that allows the rider to steer the bicycle. Headset designs can implement cup-and-cone, sealed cartridge or needle bearing systems. Because you will find two types of fork steerers (threadless, and threaded), there are two general categories of headsets. They differ primarily in the locking mechanism that secures the bearing adjustment in place. Threaded headsets use an adjustable race and a locknut threaded onto the fork. Threadless headsets use an adjustable race as well, but instead of a locknut, they use a compression ring locked in place by the stem and top cap. THESE SYSTEMS ARE NOT INTERCHANGEABLE.
 

Threaded Headsets:

The advantages of these systems are that they are inexpensive and easy to service. These headsets consist of two assemblies, the lower stack and the upper stack. The lower stack resides at the bottom of the head tube between the fork and the frame. The lower stack contains three main parts: the bearings, the pressed race and the crown race. In a cup-and-cone bearing system, the crown race is always the cone, and the pressed race is always the cup. The upper stack contains the adjustable race, the bearings and the locknut/spacer combination. The upper pressed race can be either a cup or a cone, depending on the design.
 

Threadless Headsets:

The main components of the threadless headset are almost identical to its threaded counterpart. It also has an upper and lower assembly, but the assemblies can differ across threadless systems. Threadless systems have some advantages over the traditional threaded systems. It also lacks the internal mechanisms of a threaded design (the quill, expander bolt and wedge). This creates a lighter headset assembly. This also allows a thinner, lighter and stronger steerer tube. They are also very upgradable, convenient to adjust and service, and the steerer tube can be cut to fit any combination of head tube, stack height and stem.

There are several types of threadless headsets beyond the standard threadless headset. There are internal headsets (or semi-integrated headsets), which include all of the parts of conventional headsets, but house the bearings inside the head tube. The main difference between a semi-and a fully integrated system is that the semi-integrated system uses pressed races in the head tube. This requires a specifically designed head tube, unique to this design. Prominent standards in internal headsets include: Chris King's InSet and Cane Creek's ZeroStack. The most recent style, developed around the turn of the millennium, is the integrated headset. This requires a frame specifically designed for this particular system.  In this system, the bearings are placed directly into a specially machined head tube, which replaces the need for pressed races. This means the bearings ride inside the head tube, and the head tube acts as the race. The integrated head tube can only use cartridge bearings. Unlike other systems, the headset standard is based on the size of the bearings. Prominent standards for integrated headsets include: Cane Creek's "IS" and Campagnolo's standard, which is nameless apart from the manufacturer name. These systems are very light, easy to install and easy to adjust.

 

Ed McKim
Performance Bicycle Store Associate

Bike Parts and Components