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Outdoor Research

Outdoor Research Helium UL Bivy (2026 hooped bivvy bag)

Premium Confidence: Low
  • Weight: 7/10 How much it adds to your pack.
  • Rain protection: 5/10 How well the fabric keeps out heavy, long rain.
  • Packed size: 7/10 How much room it takes in your rucksack.

Lowest price we found

£239.99 at Ultralight Outdoor Gear

In stock. Free delivery. Checked 8 Nov 2026.

RRP £275, checked 20 Oct 2026.

Go to Ultralight Outdoor Gear Compare 3 shops

Fastpacking, bikepacking and thru-hiking where a 511 g shelter is the aim

Style
Hooped
Weight
511 g
Fabric
Not published
Floor
Not published
Membrane
Pertex Shield NetPlus 2.5-layer with hydrophilic laminate
Inner length
Not published
Packed
Not published

Where to buy

Ultralight Outdoor Gear £239.99 In stock. Free delivery.

View at shop

Rock+Run £240 In stock. Free delivery. Free delivery from £100 (England and Wales).

View at shop

Outside £247.50 In stock. Free delivery. Special price, 10% off the £275 regular price.

View at shop

Prices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More

Our ratings (out of 10)

1 to 10, compared with the whole market. Each says what it's based on. How we score

Weight

From maker's figures 7/10

How much it adds to your pack. 7: Better than most.

Outdoor Research gives 511 g, in the 400–599 g band. It does not say whether that includes the pole, pegs and stuff bag. Ultralight Outdoor Gear lists 530 g for bag and pole without pegs, in the same band.

Rain protection

Estimate from maker's specs: waterproof fabric the maker names (no waterproof figure published) 5/10

How well the fabric keeps out heavy, long rain. 5: Does the job. Average for wild-camping gear.

Estimate from maker's specs

Packed size

Estimate from maker's specs: bivvy weight (no packed size published) 7/10

How much room it takes in your rucksack. 7: Better than most.

Estimate from maker's specs

In short

Good for

  • Fastpacking, bikepacking and thru-hiking where a 511 g shelter is the aim
  • Dry-weather and showery three-season nights with a low, hooped shape
  • Emergency cover on long days out, if you accept its limits in heavy rain

Strengths

  • Light at 511 g and, T3 says, a tiny pack size
  • Single DAC aluminium pole lifts the fabric off your face, with a clamshell opening
  • Fully seam-taped, with a 40D PU-coated floor and dual passive vent flaps
  • No-see-um mesh layer for bug protection on dry nights
  • Reflective trims, six stake loops and four stakes included

Weaknesses

  • Outdoor Research publishes no hydrostatic head or packed size, so rain and packed size are estimates, not reviewed scores
  • T3 found it poorly vented, hard to get into, and with no height at the foot end
  • Damp in torrential rain, so it needs a pitch away from puddles (T3)
  • Only one independent review of the 2026 bag was found, so condensation, comfort and durability are estimates, not reviewed scores

Sources

We haven't tested this ourselves. Every score comes from these specs, tests and reviews.

ShowHide sources (2)
  1. Outdoor Research: Which Bivy Is Right for You? (Helium UL Bivy fabric and weight) Specs, 4 Mar 2026. Used for: weight
  2. T3 (Pat Kinsella): Outdoor Research Helium UL Bivy review Review, 26 Jul 2026