TOOPRE Bicycle Carbon Fiber Front Fork Expansion Plug Compressor – 28.6mm Mountain & Road Bike Headset Top Cap Expander Bung, CNC Knurled Aluminum Alloy Steerer Nut Component
Upgrade your carbon or suspension fork with the TOOPRE Premium Expander Plug. Designed for 28.6mm front forks, this lightweight 39g CNC-machined component ensures a tight, gap-free fit, high strength, and seamless reusability without damaging your steerer tube.
Descriptions
Secure your headset and protect your high-end fork with the TOOPRE Bicycle Expansion Plug (commonly known as the Expansion Sunflower). Unlike traditional star nuts that can score or damage the delicate interiors of carbon fiber steerer tubes, this expansion bung uses an evenly distributed three-petal pawl design to lock securely into place. It provides maximum clamping power, absolute stability, and zero gaps for both road and mountain bikes.
Key Features
- High Strength & Lightweight: Constructed from premium T6 heat-treated aluminum alloy and paired with a heavy-duty stainless steel tie rod screw. Weighs just 39.39g to keep your bike build light.
- CNC Knurled Polish: The pawl surface features a meticulous CNC knurled pattern that increases friction, preventing slipping and ensuring a solid, unyielding grip inside the fork.
- Perfect Gap-Free Fit: Engineered for a flush, precise fit with the upper end of the front fork. It allows for repeated disassembly, adjustment, and reuse without losing its locking efficacy.
- Broad Compatibility: Universally fits standard carbon fiber front forks and mountain bike suspension forks with a 28.6mm upper outer diameter.
Technical Parameters
- Brand: TOOPRE (Authentic brand authorization available)
- Name: Bicycle Expansion Plug (Expander Bung)
- Material: Stainless Steel Screw + T6 Aluminum Alloy
- Craftsmanship: CNC Knurling, T6 Heat Treatment
- Expansion Range: 21.5 mm – 25.4 mm
- Applicable Fork: Standard 28.6mm (1-1/8″) outer diameter steerer tubes
- Net Weight: Approx. 39.39g per set
- Packaging Dimensions: 80mm x 105mm x 30mm (Branded self-sealing bag)
What’s Included in the Package
- 1x Aluminum Alloy Upper Stop
- 1x Aluminum Alloy Lower Block
- 1x Stainless Steel Tie Rod Screw (36.5mm)
- 1x 3-Piece Interlocking Expansion Pawl
Installation Instructions
- Prep the Fork: Smooth out the top edge of the front fork, ensuring it is clean and free of burrs.
- Pre-Fit: Slightly expand the plug until its outer diameter matches the inner diameter of your fork to prevent slipping, then push it neatly into the steerer tube.
- Tighten: Use a No. 6 Allen wrench to tighten the core screw until the plug is firmly locked. Ensure the top edge of your stem or spacers sits roughly 3mm higher than the expansion plug plug.
- Final Lock: Place your top cap over it and secure the vertical cover using a No. 5 Allen wrench (Note: Headset top cap/lid kit is not included).
