With an insulating layer under a windproof or waterproof jacket, maximum efficiency is achieved using a very open-knit material. That is exactly what Lowe Alpine has set out to achieve with the Diablo, which traps huge amounts of air for warmth while allowing maximum airflow to reduce any potential condensation.
The material sets this fleece apart from others, while the design packs in the basics. So you get a full-length front zip for ventilation plus extra ventilation through the two chest pockets, which are mesh-lined. Those chest pockets are positioned to be easily accessed while wearing a waistbelt or climbing harness and are big enough to stash a map, guidebook or hat. You don’t get a drawcorded waist, but this area is elasticated to keep draughts out. The wrist cuffs are also elasticated with thumb loops for those who require them. So design-wise this won’t set your heart pumping, but it’s not all about how many features you get … it is about how those features perform on the hill that really matters.
On the hill
The Diablo feels great when you first try it on indoors, and it would be easy to be sucked in by its cosy, tactile feel. But in the Lake District I was irritated by how often I needed to whip out a jacket to take the chill of the wind away. I can imagine that this open-weave fleece would be ideal in still, cold conditions (and it does feel very warm when there is no wind), but in the UK such conditions are rare. I did like the chest pockets, though, as they are big enough for maps and guidebooks. You get thumb loops, but I tend not to use them. Overall I just felt it needed more windproofness, while a hood is a benefit provided by a number of other fleeces here.
In the lab
The Lowe Alpine Diablo is warmest fleece here by a large margin, but also the most air-permeable. The result is that this is the best for staying warm in still air and is also ideal for allowing airflow under a waterproof or windproof to help control condensation. But as it is so air-permeable you’ll need a windproof in the slightest breeze to stay warm.
Material Polartec Thermal Pro, Aleutian stretch fleece
Weight 434g (size M)
Made in Romania
Stores in the UK 50
Stockist details – tel. (01539) 740840; www.lowealpine.com
Verdict: The Lowe Alpine Diablo’s open-knit fabric traps air when worn under windproof for maximum insulation; open knit allows maximum airflow for ultimate breathability; two chest pockets accessible with harness and rucksack hipbelts; elasticated cuffs with thumb loops. But it’s not very windproof, so users will need to wear a windproof/waterproof more often than other layers; and there’s no hood or drawcord hem adjustment. It’s best here for breathability and insulation, but it needs a windproof layer over the top more readily than others in UK conditions.
Review by Graham Thompson
First published in Trail magazine October 2009