Marmot's Alt HB Pullover

Special Mentions

[ * below we've bolded the relevant condition for the item reviewed here ]

Over time we've come across a number items that have really impressed us and we'd like to draw attention to, but ...

• either they don't quite fit into our rather strictly defined / narrow categories, or
• due to their high price-point, they cannot compete with our existing recommendations (mainly on the value score), or
• they will become our top choice, but only if and when our existing recommendation becomes unavailable (i.e. this item is the current heir in waiting but is just marginally edged out by our current recommendation).

So for such items we've created "special mentions" (SM). These "reviews" don't get a rating score and may receive less in-depth coverage and don't feature in our catalogue, instead the SM write-ups fall somewhere between a post and a formal review. They are identified by a blue Scramble mountain logo.

Intros out of the way, we'll proceed with our look at Marmot's Alt HB Pullover, and as always, we're looking at the item from the point of view of long distance trekking over tough terrain.

Test subject: Chest 42", Waist 33", Height: 5ft 8"
Test item: Size = Large
Kit Tests: Spring (Cold / Wet Weather), Summer (upcoming)
Disclaimer: None required (item not provided by manufacturer)

Datasheet

Manufacturer's Page

 

Scramble Review

Contents

• Introduction
• Features
• Materials
• Any Negatives?
• Conclusion & Product Images

 

Introduction: A Morass Of Mids

Scramble aren't big fans of the whole mid-layer thing. We don't even have a category for such items because we don't really think they're necessary.  Almost all mid-layers have a thermal aspect to them and our view is that most of what we feel as cold is a result of heat loss via convection (i.e. the wind) and/or being wet. As such our focus is on baselayers that keep you dry and move (wick) moisture away from the skin and softshells that provide sufficient wind-resistance without causing over-heating. Then, if necessary, add a hardshell (waterproof) to prevent you getting soaked. 

We like to recount the story of the man who fell out of a moving train in a Siberian winter wearing only a t-shirt and jeans. How did he survive the intense cold? He ran along the tracks until finally (many hours later) he made it to a station. He didn't die because during his (no doubt uncomfortable and scary) run he generated sufficient heat to stay alive. Moral of the story: don't underestimate how much heat you generate when on the move.

Trekking (unlike climbing / mountaineering) is a pretty continuous form of exertion and the body creates a good deal of heat carrying heavy loads up and down mountains or goose-stepping over boggy terrain, as such we've found, even in very cold conditions, thermal mid-layers largely unnecessary. Instead, we reserve insulation for when the body is at rest (as that's when you truly feel the cold).

That said, we're always interested in lightweight insulation and for me at least, there have been very rare occasions where I've resorted to some form of synthetic insulation whilst on the move.  Such occurrences have generally been at the end of long days, in persistent cold, wet and stormy conditions, when I'm tired, feeling sorry for myself and thinking primarily of where I can pitch to end the suffering.

The Marmot Alt HB Pullover is an interesting piece and one of very few on the relentless conveyor of outdoorsy-looking mid-layers that, in our view, has some genuine utility.

We regard the Alt HB Pullover as a lightweight, highly packable, insulation booster / utility layer that can play a role whether static or active, asleep or wide awake.
 

Features

The Alt HB Pullover is a very minimalist piece; it resembles a standard crew neck sweatshirt, but unlike a sweatshirt it has two distinct layers, which we'll get to shortly after a quick run-through of its extensive list of "features".

Marmot's Alt HB Pullover is practically featureless.

"Features"

• lycra binding at the hem and cuffs
• a small zipped side pocket (for valuables) which the pullover packs into (its position is highlighted in green above, pic #2)

Marmot's Alt HB Pullover packs away into its small side pocket.

The Alt HB's function and utility resides not in its features but in its materials ...
 

Materials

The Outer

The outer is a very breathable, soft polyamide (nylon) which has a 50 CFM (cubic feet per minute) air-flow measure, which is similar to a standard fleece. So, the outer fabric is air-permeable (i.e. not wind-resistant). To give some context a light stretchy softshell may be around 10 CFM (and a heavier softshell around 5 CFM).

Marmot also make an Alt HB Hoody which looks like it's intended as an active outer layer.  However, the outer fabric of the Alt HB is really not sufficiently durable and abrasion resistant to deal with harsh terrain. The Alt HB's destiny is most definitely trapped between a baselayer and a soft or hard shell.
 

The Inner

What makes the Alt HB interesting is the inner layer.  This layer is both the "warp-knit" lining and the insulation in the form of Teijin Frontier's Octa-Yarn:

an exceptionally unique polyester fiber with a distinctive, highly modified cross-section with eight projections aligned in a radial pattern around a hollow fiber.

We'll let Mountain Equipment (who use Octayarn in their Kinesis line) explain the benefits of this interesting, engineered fibre:

Octayarn is a multidentate (having many teeth, like a cog) fibre which boasts [an] unrivalled surface area. This makes it superb at wicking moisture, decreasing drying times and ensuring you stay dry when working hard. The multidentate fibre shape increases bulk, and subsequently its warmth. The fibre is also extremely lightweight, offering the thickness of an 80 denier fibre but with only half the fibre weight. Octayarn fibres are hollow, increasing their air trapping and resultant warmth, and further reducing their weight. Octayarn is a unique fibre ideal for use in active insulation.

It's worth pointing out that Octayarn can be used to create fleece-like fabrics (as used on TNF's Future Fleece) but can also be used as a warp-knit lining as used in ME's Kinesis range.  The Alt HB uses the latter warp-knit and doesn't resemble a gridded fleece at all.

From a distance, the Alt HB inner looks like it uses a pretty unremarkable air-tex lining. It's only when we zoom in do we see what's going on, at and below the surface.

Marmot's Alt HB has an Octayarn "warp-knit" lining.

If you think of fleece as akin to a tufty, moss-like material, then Octayarn warp knit is more like a thicket hedge. From a distance it looks ordered and uniform, but when we get close, we see a mad tangle of individual fibres, creating a three dimensional nest-like structure full of air (see right panel, below). 

The Octayarn warp-knit fibres form a 3D lofted thicket.

In many ways the Octayarn lining is doing the same job as Brynje's mesh baselayers:

At times of high activity, the mesh ensures air circulation and transports excess moisture and heat away from the body. At times of low-intensity activity or during periods of rest, the mesh cells retain warm air and form an uninterrupted insulating layer next to the skin.

So, when the Alt HB Pullover is beneath a softshell and you're working hard, the warm air is pushed away from the body and through the porous outer fabric. Heat and moisture will dissipate and evaporate via convection on the softshell's surface.

This is what makes the Alt HB (and other warp-knit items) useful utility, thermal booster layers. They'll work under traditional (synthetic or down) insulated pieces when static to provide additional warmth. They're comfortable and can be added to your sleepwear when your sleeping system is a little under-powered, and (unlike, a traditional insulated jacket or gilet) they won't cause you to sweat your arse off and get soaked from within when you're active. In addition, if you find you didn't need it afterall, you can slip it on and have something clean to wear for when you journey back into the "civilised" world (at the cost of around 230g). 
 

Packability

Where the Alt HB is similar to down or high quality synthetic insulation, is its compressibility.  The Alt HB Pullover takes up very little space in a pack (or in my case in a Tower). 

A while back, reviewing the Hagloff's LIM Barrier, we segued into the Rab Nexus Pull-On (a very decent gridded fleece) to show the difference in packability between a good fleece (pictured below right) and a very good insulated jacket (below left).

Packability test:  Haglofs L.I.M Barrier vs The Rab Nexus Pull-On

Below we've scaled the image of Marmot Alt HB (below, left) to the Rab Nexus. The Alt HB takes up about half the space.

Packability test:  Marmot's Alt HB Pullover vs The Rab Nexus Pull-On

 

Any Negatives?

The main negative is the cost.  £110 - £120 is a lot of money for a high tech sweatshirt. In our view, the Marmot Alt HB is definitely a luxury item and we would only really recommend picking one up at 35 - 50% off. Marmot are one of those brands that seem to inflate their initial asking price and then when the dust has settled you can pick the item up for something approaching sensible. I'm sure Teijin Frontier charge a premium for their high tech yarn, but has Vietnamese wage inflation got completely out of control recently or are we missing something?

The Alt HB is a practically featureless item.  In terms of design it's a pullover. If it fits you, there really shouldn't be much to dislike. However, there was one element that didn't go unnoticed and that's the crew neck, which, unlike the hem and cuffs, has a non-stretch binding. Normally this isn't an issue and I understand Marmot wanting to minimise heat-loss, but the product should come with a warning to not be used in combination with a head-torch. I used the Alt HB quite a bit after I'd pitched for the night and to sleep in.  Putting it on and taking it off will take any sized head-torch with it. Not a major issue, but a minor annoyance that was noted.

 

Conclusion

The Marmot Alt HB Pullover is the kind of item that you'd throw in your pack if you felt you might be pushing your luck on the thermal front. Unsure or what exactly might be over-powered by conditions (sleeping bag, insulated jacket, active layers), you just want something that could slot in to your existing layering to take the edge off, whether active in punishing conditions or static and just feeling the chill.

The Alt HB Pullover is an all-round, thermal booster, utility piece, that most importantly can be worn when active without causing you to over-heat and sweat profusely. 

Whether trying out modelling in high winds (as pictured below, right) or beefing up your sleepwear (when the ultralight mat you're testing has decided to leak air from its poorly sealed top side - thank you Klymit) the Alt HB might well bail you out.

How not to model a pullover in high winds.

Unlike a fleece, the Octayarn warp-knit insulation compresses like a high-end insulated jacket; the Alt HB takes up very little pack space. Yet, like a high-end tech fleece, the Alt HB is lightweight and very air permeable, allowing heat to escape when active.

Because the Octayarn "warp-knit" insulation is more a discombobulated tangle of individual fibres rather than an array of fleece tufts, the Alt HB has a degree of loft and is not prone to absorbing moisture. 

At Scramble, we're not big on the whole mid-layer / fleece concept.  However, we aren't against having add-on pieces that can provide a thermal boost when conditions turn toward the unexpected and one's overly-aggressive insulation budgeting is exposed. 

Having a utility piece that will work like an insulated baselayer booster when you're active and like a fleece under more serious insulation when static is pretty useful. Although for us this is very much a luxury item (and the price is quite unappealing), Marmot's minimalist Octayarn implementation may cover enough bases to blag its way in to your pack. As such the Marmot Alt HB Pullover is worth a special mention.

 

Product Images

 

Last Updated: 19/06/24