Problem Solvers Micro Adjustable Headset Spacer

The spacer features an integrated, threaded mechanism that allows you to apply pressure directly to the stem and headset assembly. By tightening the spacer itself, you create the necessary preload tension against the bearings, effectively bypassing the need for a traditional star nut or compression plug inside the steerer tube.

Carbon steerers are sensitive to internal pressure, and traditional compression plugs can sometimes cause damage or stress fractures if overtightened. This spacer applies load externally, eliminating the need to insert hardware into the steerer tube, which preserves the structural integrity of your carbon fork.

It is compatible with most standard stems, but you must ensure your stem has enough clamping surface area to accommodate the 12mm stack height of the spacer. Because it replaces the function of a top cap and bolt, your stem must be able to securely clamp the steerer tube once the preload is set.

Yes, once this spacer is installed and the preload is adjusted, you no longer need a traditional top cap, bolt, or star nut assembly. It creates a cleaner, minimalist look for your cockpit while simplifying the adjustment process.

While it is popular for road and gravel builds due to the prevalence of carbon steerers, it can be used on mountain bikes as long as the steerer tube is carbon and the stem is compatible. However, consider the intensity of your riding; for extremely aggressive downhill or enduro use, ensure your stem clamp is robust enough to hold the preload securely.