The FCS II CI Upright Quad Rear Fin Set - Medium is designed for surfers who want more control, stability, and tight pivot-style turning from their quad setup. Developed by Britt Merrick to pair with the upright Channel Islands side fins, these quad rears use a neutral-raked template and 50/50 foil to create a balanced, confidence-inspiring feel without sacrificing responsiveness.
Designed to Complete the CI Upright Quad Setup
These rear fins are specifically shaped to complement the CI Upright side fins, making them a strong choice for surfers who want to fine-tune a performance quad. The neutral rake helps keep the board stable and controlled while still allowing it to pivot quickly through tighter turns.
Key Features
- Quad rear fin set: Includes 2 rear fins.
- Designed by Britt Merrick: Developed in collaboration with Channel Islands Surfboards.
- Neutral-raked template: Balances control and stability with quick pivoting response.
- 50/50 foil: Adds directional control and a smooth, predictable feel.
- Performance Core construction: Lightweight material with progressive flex from base to tip.
- FCS II compatible: Designed for the FCS II fin system.
- Medium size: Recommended by FCS for surfers approximately 145-175 lbs.
Performance Core Construction
FCS builds the CI Upright Quad Rears in Performance Core, a lightweight multi-layer resin construction designed to provide a progressive flex pattern from the base through the tip. This helps the fins maintain drive and hold through turns while keeping the ride responsive and controlled.
Best for Punchy, Steep Surf
The CI Upright template is particularly well suited to hollow, steep waves and punchy beach breaks, where quick acceleration and tight turning are valuable. It also works well on performance and hybrid boards with more relaxed rocker that benefit from extra start-up speed and a responsive pivot feel.
Who Is This Fin Set Best For?
- Surfers running a quad setup with CI Upright side fins
- Riders who want tight, pivot-style turns
- Performance and hybrid boards with relaxed rocker
- Surfers looking for a balanced mix of control, stability, and speed
Rider Shack Note
Buying your FCS II CI Upright Quad Rear Fin Set from Rider Shack supports a small business and core surf shop run by surfers. We're here to help you match your fins to your board and the type of waves you actually surf.
FAQ: FCS II CI Upright Quad Rear Fin Set - Medium
How many fins are included in this set?
This is a 2-fin quad rear set, designed to be paired with compatible front quad fins.
What fin system does this set use?
These fins are designed for the FCS II fin system.
What size surfer is the Medium set recommended for?
FCS recommends the Medium size for surfers approximately 145-175 lbs.
What kind of waves are these fins best for?
They are especially well suited to hollow, steep waves and punchy beach breaks, where quick speed and tight turning are important.
What does the 50/50 foil do?
The 50/50 foil helps provide stability and directional control, giving the rear fins a balanced and predictable feel through turns.
Do these fins work best with CI Upright side fins?
Yes. They were specifically designed to pair with Channel Islands CI Upright side fins for a balanced quad setup.
