I picked up the Helium Bivy for solo bikepacking and fast-and-light hiking trips where weight and pack size matter more than sprawling luxury. After over 30 nights in it—from the Cairngorms to coastal cliffs—it’s become my go-to shelter when I want to disappear into the landscape without hauling a tent.
First Impressions & Setup
- Weight: Just under 500g (494g to be exact)—lighter than most hooped bivies.
- Packed size: About 31 x 9 cm—easily fits in a bikepacking frame bag or side pocket.
- Setup: One shock-corded Delrin pole slides into a sleeve and clips into place. Takes under 2 minutes, even in the dark. No stakes required unless you want to tension the footbox or guy out the hood.
Materials & Build Quality
- Top fabric: 30D Pertex Shield Diamond Fuse—waterproof, breathable, and surprisingly abrasion-resistant.
- Floor: 40D nylon with TPU laminate—tough enough for rocky ground.
- Mesh panel: Covers the face area for ventilation and bug protection.
- Zips: Water-resistant and smooth-running, with a storm flap and Velcro tabs.
Comfort & Liveability
- Dimensions: 208 cm long, 66 cm wide at the shoulders, 48 cm at the foot. Enough room for a sleeping pad and a bit of gear.
- Headroom: 50 cm at the apex—enough to read, check your phone, or sip tea without feeling entombed.
- Ventilation: Excellent for a bivy. The mesh window and breathable fabric reduce condensation, though you’ll still get some in humid UK conditions.
Real-world use: I’ve slept in it during a 3-day drizzle in Snowdonia and woke up dry every time. It’s tight, yes—but not coffin-tight. You can wriggle, read, and even change clothes with a bit of practice.
Weather Performance
- Waterproofing: Rated to 20,000mm HH—it’s shrugged off heavy rain and even a light dusting of snow.
- Breathability: Also rated at 20,000g/m²/24hr. Better than most bivies I’ve used.
- Wind resistance: Rock solid. The low profile and taut fabric mean it doesn’t flap or buffet in gusts.
Pros
- Ultralight and compact
- Excellent waterproofing and breathability
- Quick setup with minimal faff
- Durable materials for the weight
- Looks stealthy and low-profile
Cons
- Not as roomy as a tent—no sitting up
- Condensation still possible in humid conditions
- No internal pockets or storage
- Pricey for a bivy (around £180–£205)
Final Verdict
The Outdoor Research Helium Bivy is a minimalist’s dream: light, tough, and weatherproof enough for serious adventures. It’s not for lounging, but if you want to sleep under the stars without carrying a tent, it’s one of the best hooped bivies out there. Ideal for bikepackers, fastpackers, and stealth campers who value simplicity and performance.
