A Minimalist’s Dream Shelter
The Outdoor Research Helium Bivy is a top-tier ultralight shelter designed for fast-and-light backpackers, bikepackers, and alpine climbers. Weighing just 494g and packing down to the size of a water bottle, it’s one of the lightest hooped bivy sacks on the market.
But does its minimalist design compromise comfort or protection? We tested the Helium Bivy across UK wild camps, alpine ridges, and damp woodland bivvies to find out how it performs in real-world conditions.
Key Specifications
| Feature | Details |
|---|---|
| Weight | 494g (with pole) |
| Packed Size | 31 x 9 cm |
| Dimensions | 208 x 66 cm (shoulder), 48 cm (foot) |
| Height (head end) | 50 cm with pole |
| Material (top) | 30D Pertex Shield Diamond Fuse (2.5L) |
| Material (floor) | 40D nylon with TPU lamination |
| Waterproof Rating | 20,000mm HH |
| Breathability Rating | 20,000g/m²/24hr |
| Pole | Delrin single hoop (135 cm) |
| Mesh | No-See-Um polyester |
| Price | £205–£250 (varies by retailer) |
Design and Build Quality
The Helium Bivy uses a hooped design with a single Delrin pole that creates a raised canopy over the head. This gives it a clam-shell shape that improves ventilation and reduces claustrophobia—common issues with flat bivy sacks.
The Pertex Shield Diamond Fuse fabric is a standout feature. It’s a 2.5-layer ripstop nylon that’s both lightweight and abrasion-resistant, with a unique yarn structure that locks together like bricks for added durability.
The floor is made from 40D nylon with TPU lamination, offering excellent waterproofing and puncture resistance. All seams are fully taped, and the bivy includes reflective trims for visibility at night.
Setup and Packability
Setting up the Helium Bivy is quick and intuitive:
- Slide the Delrin pole into the sleeve at the head end
- Peg out the corners and guy line (pegs not included)
- Zip up the clamshell opening and you’re done
The pole folds down to 30 cm and fits neatly into the stuff sack. The entire bivy packs down to 31 x 9 cm, making it ideal for minimalist packs, bikepacking bags, or even large saddle bags.
Comfort and Interior Space
While bivy sacks are never palatial, the Helium offers more headroom than most thanks to its hooped design. The 50 cm ceiling height allows you to:
- Sit up slightly to read or change
- Keep your face away from condensation
- Store small items like a headlamp or phone
The shoulder width (66 cm) is generous enough for a sleeping mat and some gear. The foot box (48 cm) is tapered but not restrictive. Taller users (up to 6’4″) report having room to spare.
That said, it’s still a bivy—don’t expect to bring your rucksack inside or cook in it.
Weather Protection and Waterproofing
The Helium Bivy is built for serious weather. The 20,000mm hydrostatic head rating and fully taped seams kept us dry during:
- Heavy rain in the Lake District
- Wind-driven drizzle on Dartmoor
- Dew-soaked mornings in the Highlands
The clamshell opening zips fully shut, and the No-See-Um mesh allows for ventilation while keeping bugs out. The pole structure prevents the fabric from sagging onto your face, even in wind.
Breathability and Condensation
Condensation is a common issue with bivy sacks, but the Helium performs better than most. The Pertex Shield fabric is highly breathable, and the mesh panel allows for airflow even when zipped up.
In testing, we found:
- Minimal condensation on cool, dry nights
- Manageable moisture on damp UK mornings
- No pooling or dripping inside the bivy
As always, using a breathable sleeping bag and venting when possible helps reduce internal moisture.
Durability and Long-Term Use
Despite its featherweight build, the Helium Bivy is surprisingly tough. The Diamond Fuse fabric resists abrasion from rocks, roots, and gravel. The TPU-laminated floor is thick enough to use without a groundsheet (though we still recommend one for longevity).
After multiple nights out, the bivy shows:
- No tears or seam failures
- No zipper issues
- Minimal scuffing on the floor
It’s built to last for multiple seasons of regular use, especially if you treat it with care.
Pros and Cons
Pros:
- Ultralight (494g) and compact
- Excellent waterproofing and breathability
- Hooped design adds headroom and comfort
- Durable Diamond Fuse fabric
- Quick setup and pack-down
- Ideal for fast-and-light missions
Cons:
- Expensive compared to entry-level bivies
- Not as roomy as small tents
- Pegs not included
- Slight learning curve with pole sleeve
Comparison: Helium Bivy vs Rab Ridge Raider
| Feature | OR Helium Bivy | Rab Ridge Raider |
|---|---|---|
| Weight | 494g | 1,033g |
| Packed Size | 31 x 9 cm | 40 x 15 cm |
| Waterproofing | 20,000mm HH | 10,000mm HH (eVent) |
| Breathability | 20,000g/m²/24hr | High (eVent) |
| Pole Structure | Single hoop | Full-length hoop |
| Price (UK) | £205–£250 | £300+ |
The Helium is lighter and more compact, while the Ridge Raider offers more internal space and structure. For ultralight missions, the Helium wins on weight and packability.
Ideal Use Cases
The Helium Bivy is perfect for:
- Thru-hikers and bikepackers
- Alpine climbers and mountaineers
- Minimalist wild campers
- Fast-and-light backpackers
- Emergency shelter kits
It’s less suited to:
- Extended basecamps
- Campers who need space to sit up or cook
- Those who prefer tent-like comfort
Final Verdict: Is the Outdoor Research Helium Bivy Worth It?
The Outdoor Research Helium Bivy is a benchmark ultralight shelter. It’s not the cheapest, but it offers exceptional performance, durability, and comfort for its weight. If you’re serious about going fast and light—and you’re willing to trade space for simplicity—it’s one of the best bivy sacks on the market.
Whether you’re bivvying on a windswept ridge or stealth camping in the woods, the Helium delivers reliable protection in a minimalist package.
Rating: 9.4/10 Best for: Ultralight backpackers, bikepackers, and alpine climbers Avoid if: You need tent-like space or are on a tight budget
