Alpkit Definition Shell Review

Alpkit say their new top-of-the-range shell was 12 years in the making. That suggests the Definition should be well thought-out and well designed, and more than a match for any conditions in which a shell jacket is required. As a newcomer to Alpkit I was really interested to see if this were possible, given the highly competitive price tag.

Traversing across the top of the Great Slab  © Dan Bailey
Traversing across the top of the Great Slab
© Dan Bailey

All the mountain shells I have owned hitherto have been mid-priced 'mainstream' labels sold by 'mainstream' outdoor shops. I have to confess that before this review I had never heard of Alpkit; because of this I am ashamed to say my instinctive gut feeling was to lower my expectations of the Definition jacket. These low expectations turned out to be completely unfounded. If like me this brand is new to you, or if you've always associated it with the cheap-and-cheerful end of the market, I would urge you to try to see past the preconceptions and judge this jacket on its considerable merits. Here are some observations gained over the last couple of months of using the Definition for Scottish winter climbing and walking.

"At 490g (size M) it is competitive in terms of weight as well as price"

Fit & Cut

Fits well under a harness  © Dan Bailey
Fits well under a harness
© Dan Bailey

Breathes well when moving fast on easy ground  © Dan Bailey
Breathes well when moving fast on easy ground
© Dan Bailey

I tested the shell in size medium (I am about 5'11'' and 73kg) and this was the perfect size for me. It felt fitted and I was not aware of flapping fabric despite being able to wear a range of different layers underneath it. I found the cut and fit of the jacket not in any way restricting, including whilst using ice axes. Even though it is not the longest jacket I've worn, the bottom always stays put inside a harness when climbing; there is no need to keep poking it back throughout the day.

When the weather gets cold and gloves get bigger I usually end up conceding defeat in that frustrating battle to poke gloves inside the cuffs of my jacket. Over the outside is easier, but it always seems less satisfactory, more exposed to the elements. This jacket does feature a gusseted cuff but this was still not quite enough to easily fit over my bulky Rab Baltoro gloves (especially after getting frozen up). This is an issue I have experienced in all the jackets I have worn. Glove choice and technology seems to have come on in leaps and bounds over the last few years – perhaps jacket cuffs need to catch up in the industry as a whole? What's wrong with making them more spacious?


"There are no restrictions to vision when turning my head or looking up"

Helmet-friendly hood  © Dan Bailey
Helmet-friendly hood
© Dan Bailey

With a wired brim that resists deforming in the wind, the hood is designed to accommodate a climbing helmet without being ridiculously huge. It works for me with or without a helmet, with no obvious need for adjustment. There are no restrictions to vision when turning my head or looking up. There are a couple of minor things to be aware of with the hood though. Firstly the toggle on the back of the hood for adjusting the volume seems small and fiddly. As well as being out of sight (obviously) I've found it impossible to use whilst wearing winter gloves (perhaps easier with practice). Secondly about 1cm of the shock cord around the opening of the hood is exposed at two points on each side. These happen to coincide precisely with the headtorch clips of the Black Diamond Vapour helmet I usually wear, and annoyingly once or twice the cord has become trapped in the clips, preventing the hood from being pulled back.


Unusually for a shell jacket the 'mystery' fabric is described only by its technical specifications. These are very respectable, comparing well on paper with big brand name waterproof/breathable fabrics - a hydrostatic head of 30,000mm and a MVTR (moisture vapour transmission rate) of 20,000 g/sqm/24hrs.

Here's what Alpkit have told us about the fabric:

"We select our waterproof fabrics based on performance without being tied to any particular brand. The Definition fabric uses a UK made membrane that is engineered to a high performance standard and then laminated in the Far East to form the fabric used in the Definition."

I would guess that not using a named fabric helps with the very competitive pricing, while on the other hand it doesn't seem to have disadvantaged the performance of the Definition. In use in a range of winter conditons, and wearing various layers underneath on different occasions, I've found breathability good. That's an anecdotal rather than a controlled scientific test, but it does at least suggest that Alpkit are onto a winner here.

"waterproofness and breathability are very respectable, comparing well on paper with big brand name fabrics"

The outer surface has quite a 'slippery' feel to it, while inside it has a mesh-like layer. Overall it seems on a par for toughness with other 'mountain-weight' fabrics. I've certainly not yet managed to make any holes in it. The fabric has a substantial degree of two-way stretch, which along with the great fit makes the Definition feel comfortable and unrestricting.

For the price, it's a brilliant climbing shell
© Dan Bailey

Keeping off an icy Cairngorm wind
© Dan Bailey

I cannot yet comment on the long-term resistance to wear and tear, however in its favour the same weight of the tough fabric is used throughout the jacket. Despite this the overall weight of the jacket is not excessive (<500g in my size) for a full-featured mountain shell.

Finally, I was lucky enough to be wearing the Definition jacket whilst Christmas shopping in the torrential downpours of hurricane Barbara – it proved totally watertight, keeping me and my wallet bone dry!


The zips on the pockets and vents have external seals (YKK AquaGuard) and certainly seem waterproof; the main zip on first inspection seems a bit more exposed to the elements but it is sealed too (YKK Vislon AquaGuard). All of the zips have a good sized toggle with a rough surface which are easy to grasp even with frozen up gloves and cold fingers.

Something I did not notice to start with is that the zipped vents are not under the armpits, they are located slightly lower and forward so you can get your hand in them. This enables you to access the side pockets of garments worn underneath without having to undo the shell - a nice touch.


The outside chest pocket is definitely not a 'map pocket' – it is the perfect size for a large mobile phone or packet of jelly babies and that's about it. There is a similarly sized internal pocket. The two external hand pockets are more generously sized, and remain easily accessible when wearing a climbing harness or rucksack hipbelt.

Cut reasonably long in the hem, with plenty of coverage at the rear  © Dan Bailey
Cut reasonably long in the hem, with plenty of coverage at the rear
© Dan Bailey


The concealed 'Cohaesive' adjusters at the hem and the hood remove the clutter of external toggles and help the minimalist look and feel. In use they are less fiddly than floppy external toggles too. The tail end of the hem shock cord adjustors is located inside the hand pockets – this means there are no dangly bits! The hood visor toggles emerge onto the outside of the jacket at chest level and have a good sized lump of plastic on the end, meaning they are easy to use wearing gloves. Also these are far down enough and heavy enough not to flap about in strong wind and smack you in the face. Furthermore being at chest level means you can see them, so there is no groping about for hood toggles with numb fingers. Personally I found the cut of the jacket so good that I never felt compelled to make any adjustments despite climbing and walking in a wide range of Scottish winter mountain conditions.


I have been wearing the Alpkit Definition all day over the top of an Alpkit Katabatic insulated jacket (a review of that is pending) and this has proved a good double-act. These items are the perfect mountain combination – there's no awkward mismatch of compatibility or proportion at the bottom hems, cuffs or the hood.


The Definition screams good design - and this does not mean cluttered with excessive features. Alpkit have not tried to add lots of superfluous bells and whistles; the Definition is instead neat, simple and tough. However all the mountain essentials are there, and are discretely assembled to give a minimalist and functional jacket; at 490g (size M) it is competitive in terms of weight as well as price. I would say that it does indeed feel like the result of 12 years of development. For the price it really seems a steal, and it also looks great! Is the Alpkit Definition the best mountain shell you've never heard of? At this budget, quite probably.

Alpkit say:

12 years in the making, our fully waterproof and breathable Definition jacket is engineered to cope with whatever you, the mountains, and the weather can throw at it.

The Definition jacket is a fortress, it is designed to face the foulest, wettest, windiest, snowiest, wildest weather. Fully featured and tough as old boots, this is the jacket that will take whatever abuse you want to throw at it, from Scottish winter and alpine climbing to Munro bagging.

Definition is breathable and waterproof. Its face fabric and backer are manufactured from tough nylon for superb durability. Sandwiched between these is a waterproof / breathable PU/PTFE membrane; the result is the best combination of durability and breathability available in heavier weight 3-layer fabric. It is our most durable jacket yet.

Fit for purpose doesn't just mean waterproof - it has to fit you! Definition is designed to sit over your other layers, its cut is tuned so that it does not ride up to expose your back or tum when you swing your axes above your head. The hood is large enough to fit over a climbing helmet and deflect spindrift from engulfing your core.

  • Price: £210
  • Sizes: S - XXL (mens) 8 - 14 (womens)
  • Weight: S 485g M 490g L 530g XL 550g XXL 580g
  • Fabric: 145 gsm 3-layer fabric Face: 40 D x 90 D Nylon Backer: 20 D Nylon tricot Bi-component PU/PTFE membrane 20d nylon tricot
  • Stats: Hydrostatic head: 30,000mm MVTR: 20,000 g/sqm/24hrs
  • Helmet compatible hood with wired peak, embedded Cohaesive™ front adjusters and easy-grab rear adjuster
  • 2-way opening YKK Vislon AquaGuard® front zip
  • Internal storm flap with bottom snap and chin guard
  • 2 map sized hand pockets (positioned above harness/ waist belt) with YKK AquaGuard® zips
  • 1 external chest pocket with YKK AquaGuard® zip
  • 2 core body venting YKK AquaGuard® zips, inverted for ease of use
  • Gusseted cuffs with anti-snag Velcro adjustment
  • Embedded Cohaesive™ hem adjusters, accessible from inside hand pockets or at the hem
  • 1 internal YKK zipped chest pocket

For more info see

16 Jan, 2017
Is it a 'coil' or a 'vislon' style zip for the main zip?
16 Jan, 2017
Looks like a vislon or perhaps even a Riri zip:
It's a YKK Vislon AquaGuard - it's under the Zips heading in the review ;)
16 Jan, 2017
16 Jan, 2017
I need to improve my reading comprehension, it is a Vislon zip which is nice. Edit: Doh! ;-)
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