Shock absorber bushings & claws

Function of the star nut and shock bushing

We explain the function of the star nut and shock bushing as components and parts of the suspension system. 

Star nut: connection between stem, fork & frame

The star nut - also called a fork star nut - is part of the headset system. It ensures that the stem can be clamped securely and without play onto the fork steerer. The star nut is recessed into the steerer and uses the top cap to apply the correct preload to the headset. It is driven in straight and evenly. Once installed, it remains permanently in the steerer.

On aluminum and steel forks, the classic star nut is standard. Carbon fork steerers, on the other hand, require an expander because a star nut would damage the material.

Shock bushing: link between frame and shock

Shock bushings are small but essential components for full-suspension bikes. They connect the bicycle shock to the frame and ensure a play-free fit. The main differences are in the mounting width (e.g., 22.2 mm) and bolt diameter (usually 8 or 10 mm). This is why there are specific Fox shock bushings and Rock Shox shock bushings, which must fit the respective shock eyelets and frame mounts exactly.

A shock bushing sits in the shock eyelet. It reduces friction, protects the bolt, and prevents play between the frame and shock. Worn bushings can cause creaking, play, or imprecise handling - they should therefore be checked regularly and replaced when necessary.

What types of shock bushings are available?

• Standard bushings for common bolt and width dimensions
• Manufacturer-specific kits - e.g., Fox shock bushings or Rock Shox shock bushings
• Special solutions for unusual frame-shock combinations

Whether you need Fox shock bushings or Rock Shox shock bushings - the choice always depends on your bike's material and dimensions. With the right parts, you can ensure that the suspension and headset work reliably and that you can enjoy riding for years to come.

How far should the star nut be driven in?

As a rule, approximately 15-20 mm below the edge of the steerer. This allows the top cap bolt to engage securely and distributes the preload evenly. Important: do not drive it in too far, otherwise the headset cannot be adjusted correctly.

Practical tips for installing star nuts and shock bushings

1. Determine the dimensions precisely for shock bushings - only correctly fitting bushings prevent play.
2. Install bushings with suitable tools and do not tilt them.
3. Install the star nut with a dedicated installation tool and drive it in evenly.
4. Carbon fork steerers: always use an expander/compression plug instead of a star nut.

Star nut and suspension - what is the connection?

The star nut on your MTB or e-bike is not directly part of the suspension system. Nevertheless, it plays an indirect role in the function of a suspension fork. Only when the headset is adjusted correctly can the suspension fork operate without play and deliver its suspension and damping characteristics optimally. A correctly installed star nut ensures that the fork runs straight, prevents unwanted movement in the head tube, and distributes forces evenly. It is therefore a small but essential link between the frame, headset, and suspension fork.

Conclusion: star nuts and shock bushings are small parts with a major impact

Although shock bushings and the star nut may initially seem like inconspicuous small parts, they are crucial to your bike's functionality. Shock bushings provide a play-free and durable connection between the frame and shock - without them, precise handling would hardly be possible. The star nut, in turn, ensures that your headset is correctly preloaded and that the steering works reliably. Both components are therefore essential parts that ensure stability and riding enjoyment. 

Discover a range of shock bushings and star nuts in our shop!