Surf fins designed to add stability and top-end speed for twin-fin fish and shortboard setups, the UP100 Twin Keel Fins are a double-tab compatible keel set. Riders seeking a lively, loose feel with predictable tracking will find more confidence on open faces and punchy beach breaks. Do these keels match your board's fin boxes and riding style?
⚡ At a Glance
- • Ride Character: Stable at high speed yet responsive during rail-to-rail transitions
- • Best for: Twin-fin fish and retro shortboard surfers seeking extra drive
- • Not ideal for: Boards that require single-fin setups or non-double-tab fin boxes
Twin-keel fin set compatible with double-tab FCS and FCS II systems. Flat foil with a 160mm base and 118mm height, made from lightweight, high-strength nylon and fibreglass reinforced polymer for stability and control at speed.
Stable High-Speed Tracking – With nylon and fibreglass reinforced polymer
Composite construction pairs lightweight nylon with fibreglass reinforcement to increase strength and resistance to flex. The result is a stiffer keel that maintains drive when generating speed.
Improved hold through fast sections, so paddling into and riding open faces feels more controlled and predictable.
Smooth Rail-to-Rail Flow – Thanks to flat foil and sweeping arcs
Flat foil combined with a smooth, sweeping arc profile reduces drag while promoting quick pivot. Dimensions are quoted as a 160mm base and 118mm height, supporting a low-drag template.
Quicker, looser turns with reliable release off the tail, ideal for the short, snappy lines typical of fish-style boards.
Simple Fit for Double-Tab Boxes – With FCS/FCS II compatibility
Sold as a two-fin set and designed specifically for double-tab fin systems, compatible with both FCS and FCS II style boxes. Packaging confirms two fins per pack.
Quick upgrade path for twin-fin boards that use double-tab fittings, suitable for both modern and retro twin-fin designs.
✨ The 4 Key Reasons for UP100 Twin Keel Fins
- Nylon and fibreglass reinforced polymer - Maintains stiffness while remaining lightweight for sustained speed
- Double-tab FCS/FCS II compatibility - Fits most double-tab twin-fin boxes without modification
- Flat foil, 160mm base, 118mm height - Low drag profile for stable hold at pace
- Twin keel outline for fish and shortboards - Encourages loose turns and strong rail-to-rail drive
📋 Technical Details at a Glance
- Category: Surfboard fins
- Brand: UP100
- Material: Nylon and fibreglass reinforced polymer
- Compatibility: Double-tab FCS / FCS II
- Fin type: Twin Keel (2 fins)
❓ Frequently Asked Questions
Q: Are these fins compatible with both FCS and FCS II boxes?
A: Yes, the fins are double-tab compatible and specified for use with FCS and FCS II style fin boxes.
Q: What materials are the fins made from?
A: Construction uses lightweight nylon combined with fibreglass reinforcement, described as a high-strength reinforced polymer.
Q: Which boards suit these keels?
A: Designed for twin-fin fish surfboards and both modern and retro shortboards, offering a balance of speed and loose turning.
🏆 Our Verdict
Ideal for surfers who ride twin-fin fish or retro shortboards and want faster, more confident runs. Durable nylon and fibreglass-reinforced construction combined with a flat foil delivers stable, low-drag performance and lively rail-to-rail turns. Although retail cost varies, the robust materials and straightforward compatibility suggest solid long-term value for regular surfers.
