The ADVANCE STRAPLESS BI 4 is an ultralight tandem pilot harness tailored for expert hike-and-fly mountaineering pilots demanding minimal weight without compromising on certification and functionality. Weighing merely 420 g for size M and 440 g for size L, including the integrated reserve system, it stands among the lightest EN-certified tandem harnesses on the market. This makes it ideal for pilots tackling long, technical ascents with a tandem wing, where pack weight is a critical factor.
Design and Purpose
The STRAPLESS BI 4 departs from traditional tandem harness designs by eliminating airbags and foam protectors—increasing risk tolerance for reduced weight and pack volume. It targets highly experienced tandem pilots engaged primarily in hike-and-fly, ski mountaineering tandems, or expeditions, where lightweight gear outweighs passive safety or comfort. The harness’s classic strap-style design uses high-strength 4 mm Dyneema webbing rated up to 13 kN, combined with durable nylon reinforcements and Skytex 32 canopy fabric, underscoring its minimalist, high-performance ethos.
Certification and Load Capacity
Despite its stripped-back construction, the harness meets the stringent EN 1651:2018+A1:2020 standard, accommodating tandem loads up to 120 kg, ensuring reliability in demanding alpine conditions.
Key Features
A pivotal feature of the STRAPLESS BI 4 is the integrated reserve container placed beneath the pilot’s right leg pad, with an included extraction handle. This placement optimizes compactness and accessibility close to the center of gravity, streamlining emergency procedures. ADVANCE recommends pairing the harness with lightweight tandem spreaders and a lightweight SQR Light reserve, maintaining the ultralight philosophy which also manifests in using Maillon Rapide connectors and O-rings instead of bulkier carabiners.
Sizing and Flight Feel
With two sizes (M and L), the harness accommodates pilots from 155–185 cm and 178–202 cm respectively. Chest strap widths and adjustable leg loops provide predictable in-flight stability and weight-shift control. The absence of a rigid seatboard results in a direct, connected flight sensation valued for technical and alpine tandem flying, albeit less forgiving on takeoffs and landings.
What Pilots Appreciate
- Extreme lightness and compactness: Customers consistently praise the harness for its remarkable low weight and minimal pack volume, essential for long approaches and technical sorties.
- Clean integration of reserve system: The neat, EN-compliant reserve container with its ergonomic layout receives high marks for accessibility and ease of setup with tandem spreaders.
- Simple, efficient handling: The minimalist strap system is favored for quick donning and adjustment, crucial in alpine environments where speed and simplicity matter.
- Clear sizing and geometry: Defined sizes assist pilots in selecting the correct fit, contributing to reliable flight dynamics despite the minimalist string-harness design.
Trade-offs and Limitations
- No impact protection: This harness omits airbags and foam protection to save weight, a compromise making it unsuitable for commercial pilots or those seeking passive safety during repeated or rugged flights.
- Minimal comfort: The string-style construction with limited padding results in less comfort for long or heavily-loaded flights, acceptable only for short, weight-focused mountain missions.
- Niche usability: The STRAPLESS BI 4 caters explicitly to advanced pilots who can handle the inherent risks and technical demands of hike-and-fly tandem flying on generally benign terrain.
Ideal Users and Unsuitable Pilots
The harness delivers maximum satisfaction for highly experienced tandem pilots who prioritize weight savings, compactness, and minimalist functionality over comfort and protective features. Conversely, it is not recommended for commercial tandem flying operations, long-duration scenic flights, less experienced pilots, or anyone requiring extensive integrated protection.
Conclusion
Overall, the ADVANCE STRAPLESS BI 4 represents a specialized ultralight tandem harness crafted for expert hike-and-fly mountaineering pilots. It embraces deliberate trade-offs—foregoing comfort and impact protection to achieve performance and weight advantages. It is a precise tool rather than an all-purpose harness, excelling in its defined role yet limiting its appeal beyond a niche of seasoned tandem pilots focused on mountain efficiency.
For more detailed information and to explore this harness, visit the manufacturer's website. To order the ADVANCE STRAPLESS BI 4 and related equipment, visit Paragliding4.me.