Monday, 27 November 2017 09:54

Rab Alpha Flux 3 month test and review Featured

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We put Rab's Alpha Flux jacket through 3 months of extensive testing; wearing it for more than 40 days as we threw it at everything from summer walking in the Peak District to downhill singletracks in Switzerland. They say a jack of all trades is master of none. After a serious testing we feel Rab may have proved the exception to this rule with the Alpha Flux.

It's a hoodie and a jacket, a mid-layer and an outer layer. It works with bike, ski, and climbing helmets and is at home cruising the skies above Zermatt as sitting at windswept Lake District crag belaying a partner.

What the manufacturers say:

The Men's Alpha Flux Jacket is a highly breathable, lightly insulated outer or mid-layer that uses Polartec® Alpha™ ‘Direct’ technology and stretch fleece for ‘on the move’ multi-season use.

The Men's Alpha Flux Jacket is shelled in a new super-soft yet durable, woven outer fabric which has a high level of air permeability. This is paired with our Thermic-lux™ light, stretch fleece in strategic areas of the body to allow freedom of movement and to reduce bulk. The result is the perfect insulation piece, created with Polartec® Alpha™ “Direct” 90 insulation; ideal for changeable conditions from early Spring right through to late Autumn.

As an outer layer the Men's Alpha Flux Jacket keeps your body temperature in balance when you need a degree of warmth while working hard in the mountains. It also serves impeccably as a warmer, fast drying mid-layer in windier, cooler conditions.

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  • Weight: 330g/11.6oz (estimate)
  • Polartec® Alpha™ “Direct” 90 insulation
  • Under helmet hood
  • YKK front zip, internal storm flap, chin guard
  • 2 YKK® zipped hand pockets
  • Stretch fleece side panels, cuffs and thumb loops with Polygiene® STAY FRESH odour control treatment
  • Fit: Slim
  • Price: £140

Rab Alpha Flux on test:

It's not easy classifying exactly what the Rab Alpha Flux jackets is; Rab describe it as a "new breed" of product, but is it a mid layer or an outer layer? In practice, over a period of 3 months it's actually proved itself more than capable of fulfilling both functions.

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Visually it looks like a throwback to the early days of fleece, resembling a shaggy carpet on the inside, but in terms of performance it's very much 21st century. The Polartec Alpha provides superb insulation when needed but the Alpha Flux is simultaneously one of the best wicking fleece layers we've experienced. The combination of features make the Alpha Flux suitable for a wide range of activities from hill walking to ski touring and climbing to alpine single track.

With an under-helmet, rather than over helmet, hood the Alpha Flux fits the profile of a fleece mid layer, and under a waterproof shell it does provide good levels of insulation while maintaining breathability. Without an additional shell, however, the outer fabric manages to shed water well enough to handle a shower. The front storm flap and high collar, combined with close fitting hood, mean that once fully zipped up the Alpha Flux proves to be a very effective barrier against the elements.

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Shaggy pile panels provide insulation

The front hand-warmer pockets take up the majority of the front of the jacket, the whole front panel being more than large enough to take an OS map. Thumb loops and side panels are made from stretch fleece which allows a fit that pulls the fleece close to the body, making the most of the insulation and trapping warm air very efficiently.

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The front pockets take up the whole of the front panels

So far, so good then. It's a mid or outer layer that insulates well without getting too hot when on the move. But there's a lot of mid/outer layer fleeces jackets on the market so what makes the Rab Alpha Flux stand out? Ironically it's the not knowing exactly what it's designed for that's its strongest point. It's immensely comfortable to wear. The stretch panels down the sides and on the inner side of each arm hold the jacket close but provide breathability as well as total flexibility. Meanwhile the shag-pile style fleece keeps the cold at bay whether sitting at a belay for prolonged periods or cruising the heights above Zermatt on a paraglider. Taking on alpine single tracks in late autumn the Alpha Flux was in its element, the insulated front panels handling the cool Swiss air at speed without fuss. No matter what we threw the jacket at, the internal temperature staid remarkably stable irrespective of the activity or amount of exertion.

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One half of each arm is shaggy-fleece, one half stretch fleece

When the time to wash the Alpha Flux comes around, and with a Polygiene Stay Fresh treatment that's not that often, it's very quick drying. Weighing in at a touch under 330 gm for a medium the jacket is lightweight enough to carry in your pack but in reality the chances are you're more likely to be wearing it than carrying it. It's just so comfortable to wear that it becomes the centre-point of your clothing around which you add optional extras from base layers to lightweight waterproof shells. The Polygiene treatment allows multiple days of active use, even as a sole base/mid/outer layer, without smelling excessively and the close fitting hood means you can use it under bike, climbing or skiing helmets.

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If there's any negatives to be found with the Rab Alpha Flux it's durability. Although we've put the jacket through over 40 days use over the late summer and autumn we were surprised to find some of stitching around the hem has started coming apart. It hasn't caused any loss of function and it's a simple fix in a relatively invisible area but something to watch out for.

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Last modified on Wednesday, 29 November 2017 09:35

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