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May 2019 Issue
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Therm-A-Rest Hyperion 32



Our Rating:

At a glance
Plusses: Lightest down bag in its class, efficient design, high-quality fill.
Minusses: Price.

Weight: 454g

Features A lightweight three-season bag with 900-loft Responsible Down Standard-certified Nikwax hydrophobic goose down, SynergyLink mattress connectors, a ThermaCapture lining to trap radiant body heat, zoned insulation places 70 per cent of the fill on the top and sides. It is EN13537 rated to 5°C (comfort), 0°C (limit), -15°C (extreme).

Fit With a tight fit across the chest and tapering heavily at the feet, the bag has no dead space. It’s restrictive and requires a little getting used to. 4/5

Comfort The tight fit leads to a super cosy bag. The footbox is excellent, allowing feet to rest in a natural position and because there’s minimal weight pressing down here, due to the majority of the fill begin around the upper body, it’s the most natural-feeling bag of those reviewed. Once inside, warmth is almost instant, radiating across the chest and upper legs

In use This bag is new for 2019 and its shape and features are completely different from any other comparable bag. The 900-fill down is as good as you can get, which means just 245g is used to achieve the desired temperature ratings. It compresses to the size of a small loaf of bread – half the size of the other bags reviewed. That makes it a delight to carry.

Another weight-saving measure is the half-length zip. This helps keep the bag warm but makes it less easy to get into and out of. With such a tight fit, I used the mattress connectors to ensure I stayed on my mattress and to prevent bag roll. In the past, I’ve thought connectors to be gimmicky but found I had a less disturbed sleep when I used them.

The chest area is tight – if the zip is done up with arms outside the bag, it’s impossible to get them inside again. The zip also has a tendency to unzip with every movement, so it’s essential to use the dome closure at the neck. The hood has a single drawcord which pulls the opening to virtually nothing, helping trap warmth. It was just roomy enough to accommodate my inflatable pillow. The zip is backed by a nylon webbing to prevent catching on the bag fabric, but I found it caught often around the shoulder.

Value: This is an innovative bag, minimising weight without compromising performance. It is staggeringly light, but the price makes it one for the committed user.

Verdict: A bag this light and that uses the best down fill is an attractive proposition. Pair it with TAR’s UberLite mattress for a sleep system that weighs around 700g. But first, you’ll need to get over the cost.

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