The PRO Gap Cap Expander Long UD Carbon 50mm is a headset expander designed specifically for carbon fork steerer tubes. Its 50mm-long expander provides a secure internal clamping interface without using a conventional star nut, helping protect the carbon steerer during headset and stem installation.
Key Features
-
50mm-long expander design
-
UD carbon top cap
- Designed for carbon steerer tubes
- Available in 1 1/8-inch and 1 1/4-inch versions
- Requires a minimum 23mm internal steerer diameter
- Provides internal support for carbon steerers
- Replaces the need for a conventional star nut
- PRO part number PRHS0072 for the 1 1/8-inch version
Specifications
| Specification |
Details |
| Brand |
PRO |
| Product |
Gap Cap Expander Long |
| Type |
Long steerer expander |
| Steerer Size |
1 1/8" |
| Expander Length |
50mm |
| Top Cap Material |
UD Carbon |
| Minimum Internal Diameter |
23mm |
| Application |
Carbon fork steerers |
| Part Number |
PRHS0072 |
| EAN |
8717009339247 |
| Colour |
Black / carbon |
PRO's current product information confirms the 50mm expander length and 23mm minimum internal diameter.
Benefits
-
Carbon-safe installation: Provides internal support without relying on a star nut inside the carbon steerer.
-
Extended support: The 50mm length distributes the clamping/support area over a larger section of the steerer.
-
Clean cockpit finish: The UD carbon top cap complements performance-oriented carbon cockpits.
-
Reliable headset adjustment: Designed to provide the compression interface needed when setting headset preload.
Compatibility
The 1 1/8-inch PRHS0072 version is intended for compatible carbon fork steerers with at least 23mm internal diameter. Check the fork manufacturer's requirements before installation and follow the specified torque settings.
Best Suited For
- Carbon road-bike forks
- Carbon gravel-bike forks
- Performance MTB forks with compatible carbon steerers
- High-end cockpit builds
- Replacing a conventional star-nut arrangement on a carbon steerer
