PRO Cap Carbon 1-1/8-inch bicycle headset spacer set - PRHS0118

The PRO Gap Cap Expander Carbon PRHS0118 headset expander is designed for cyclists who are conscious of their bike’s weight and performance. Weighing just 24 g, this accessory helps to lighten the handlebar area whilst offering a solution suitable for carbon fork steerer tubes.

Developed by PRO, a specialist in cycle components and accessories, this expander combines an alloy construction with a carbon top cap. It is particularly suited to lightweight set-ups and sporty road bikes, especially when paired with a high-end cockpit such as the PRO Vibe Superlight.

A lightweight expander for carbon fork steerer tubes

The PRO Gap Cap Expander Carbon is designed for forks fitted with a carbon steerer tube compatible with a 1-1/8-inch diameter. It replaces the traditional star-shaped spacer when this is not suitable for the steerer tube design.

Its internal expansion system provides the necessary support for adjusting the headset preload. It is essential to follow the fork manufacturer’s instructions to ensure correct installation and preserve the integrity of the steerer tube.

An aluminium and carbon design

The body of the expander is made from an alloy, whilst the top cap is made from carbon. This combination prioritises lightness and provides a sleek finish to the handlebar area.

With a claimed weight of 24 g, the PRO Gap Cap Expander Carbon represents a weight saving of 16 g compared to the previous model, according to the manufacturer’s data. It is aimed at cyclists who wish to optimise every component of their build without compromising mechanical compatibility.

Compatible with suitable bike stems

The PRO Gap Cap Expander Carbon is advertised as compatible with all stems. However, the overall compatibility of the setup depends on the steerer tube diameter, the stem used and the recommendations of the manufacturers of the various components.

The PRHS0118 version is suitable for a 1-1/8-inch steerer tube diameter. For a 1-1/4-inch steerer tube, the PRO PRHS0119 model should be selected.

Technical specifications of the PRO PRHS0118

• Brand: PRO
• Model: Gap Cap Expander Carbon
• Manufacturer’s reference: PRHS0118
• Compatible diameter: 1-1/8 inches
• Length: 25 mm
• Body material: alloy
• Upper cap material: carbon
• Weight: 24 g
• Application: compatible carbon fork pivot
• Stem compatibility: all stems, provided the fitting specifications are met
• Alternative part number: PRHS0119 for 1-1/4-inch steerer tube