Rab Infinity G Down Jacket Review

9th Feb 2018

Rab Infinity G Down Jacket

Whether belaying at a chilly gritstone crag, putting in a lengthy belay session on a multi-pitch winter route or settling in to a frigid Alpine bivvy - a lightweight yet highly insulating down jacket offers great versatility for outdoor goers in so many situations.  

For decades Rab have led the way in down garments and I’ve used many of their products along the way.  I even remember being able to visit their original manufacturing facility in Sheffield and Rab Carrington himself would regularly be doing the rounds chatting to the machinists on the production floor.  The focus was always about producing the very best products for climbers and Alpinists operating in the world’s  most hostile environments.  

Things have moved on for Rab and nowadays they are world leaders in clothing manufacture, but they have still kept their core focus and they are still essentially a close knit group of climbers and outdoor people aiming to make the very best products for climbers and Alpinists.  If you visit their facilities in south Derbyshire you will still see the down clusters floating in the air from their filling facility and the buzz of machines repairing clothing sent in by customers. 

Rab are experts in a wide range of fabrics and technologies, but down products are still at the very heart of what Rab are about and, over the autumn and winter, I’ve been privileged to test one of their state of the art Infinity G jackets…….


The Infinity G is described by Rab as being a specialist down jacket created for the Alpinist.  It is, they say, a lightweight, packable and exceptionally warm garment which excels at low temperatures and high altitudes.  

To create the correct balance of warmth, weight and performance Rab have combined a 7D Pertex Quantum outer fabric with a nylon inner lining and then, within this sandwich, they have added 240 grams of 850 fill power hydrophobic European goose down held in place with a quilted stitch through construction.

The jacket has a full length baffled 2 way YKK Vislon front zip, a helmet compatible hood, 2 YKK zipped hand warmer pockets and a YKK zippered interior pocket.  Too finish the package there is a hem drawcord and elasticated stretch woven cuffs.

The Test

The Infinity G Rab sent me has been put to very good use in the last 4 months.  It came along on an expedition to Myanmar, has sent time in -20 degree Celsius temperatures in Norway, has been doing winter duty in the French Alps and, in between all that, has been on a couple of Scottish snow shelter trips and has been a belay option in Scotland and the Peak District.  I wanted to make sure the jacket was tested in a range of temperature levels and different humidities and for different activities - I am very happy the Infinity G has been well and truly put through it’s paces.

In Use

The first thing you notice about the Infinity G is undoubtedly its appearance - it is a striking and, in my opinion, very attractive jacket.  This comes in part from the shiny nature of the Pertex GL outer fabric and also from the box stitched compartments that keep the down in check. The review model we received was a lovely burnt orange colour option (known officially as Dark Horizon) but it is also available in blue or black.  I understand that the shiny surface of Pertex GL is because these fabrics can’t be made in a matt finish without adding weight (and low weight is an important design factor for this jacket) but I think it looks great like this.  

While talking about the fabric it is also worth mentioning that it has a slight translucence meaning you can often see the down inside.  This isn’t a problem but it can give the appearance of darker patches on the surface.  I certainly don’t see this as a problem but it is worth pointing out incase that’s a problem for you. I suspect it would be less noticeable with the darker colour fabric options.

So, while it wouldn’t be right, given the environments the Infinity G will be working in, for appearance to override performance, at the end of the day it is still better to be holed up on a ledge looking good!  Of course, most mountain jackets will also spend a fair chunk of their time on  walking to the pub duty or for other general tasks anyway and so again appearance is important.

Leaving aside looks, the biggest consideration for most down jacket users will be the warmth to weight ratio.  For the Infinity G Rab have used 240 grams of high quality 850 fill power down (size large) which is a large amount - many sleeping bags would only be close to containing this amount and certainly many wouldn’t be filled with down of this fill power (fill power is a measure of how well down will expand after being compressed and correlates to a down products warmth to weight ratio).  

Put simply, the Infinity G’s combination of high fill power down and large down quantity ensure this is a very warm jacket for its weight but the high quality and high fill power down also ensures the Infinity G lofts quickly and efficiently.  When you pull the jacket from its stuff sack and shake it a few times the Infinity G is nicely lofted in seconds - this is a really important consideration for a jacket that will be pulled out of a pack for belays but then shoved back into a pack several times a climb.  

The down is kept in place by square sewn pockets that are stitched through between the inner and outer fabric.  I was unsure how warm a stitched through jacket would be as I’ve been brought up to think box wall baffles are far more thermally efficient than a stitch through construction.  With the Infinity G Rab are striking a balance between lightness and warmth and so the choice to use a stitch through construction makes sense given the extra fabric needed to create the box wall structure.  In reality, I haven’t noticed any cold spots and the jacket was plenty warm enough for prolonged belay duty even in the frigid -20 degrees Celsius conditions of Norway.  

Another part of a jacket that can allow heat to escape is through a long front zip, but Rab have considered this and added a substantial baffle to minimise this. This is a great addition and shows that, even though keen to keep weight down, Rab won’t let low weight override performance.  The baffle also ensures the zip won’t get caught on the inner fabric and, as they have also used a high quality 2 way YKK Vislon zip, it operates smoothly every time.  There is also the nice addition of a zipper garage at the top so the zip doesn’t rub against your face and the 2 way zipper is also appreciated when the jacket is used for belay duty where you may want to access a harness belay loop.

So, the jacket offers really high warmth in the body and so the final consideration in the overall warmth is the hood design.  I’ve used a number of down jackets over the years where the hood just doesn’t feel filled enough for a decent level of warmth but I’m delighted this isn’t the case with this one - the hood is a bundle of fluffy warm that makes a substantial difference when you pull it up at a windy belay.  

Rab say the hood is helmet compatible and I agree.  It fits comfortably over a Petzl Meteor or Elios size helmet and the zip can still be fully closed.  There is a stiffened brim that works fine and rather than use a traditional drawstring closure at the front Rab have used an elasticated system that. while not offering adjustment, actually works well and seals the hood nicely around the face.  Finally, because it is a hood sized to fit over helmets, it can feel big when you aren’t wearing  helmet and so has a simple velcro volume adjuster at the back. 

While rattling through the features I will also just mention there is a zipped inner pocket, 2 zipped hand warmer pockets, a drawcord bottom hem and elasticated cuffs.  Other nice details include zipper pulls on the main zips and zipper garages for the hand warmer pockets.  Everything you need and nothing more. 

So, the Infinity G is very warm and has all the features you will need - and so it is time to consider how it stacks up against other jackets.  The Rab design brief for the jacket was clearly to make an extremely warm jacket with minimal weight.  We have covered the warmth part, so how does the weight stack up?  Well, as mentioned, the Infinity G has 240 grams of down for a size large and weighs 488 grams.  To put this into perspective the long established Neutrino (a jacket I reviewed some years ago for UKClimbing and you can still read here) contains 250 grams of 800 FP down for a size large and yet weighs 635 grams.  That is still a very good weight for a down jacket and yet is still a significant 147 grams more for a jacket of either comparable warmth.  

This weight reduction largely come down to the use of lighter weight outer and inner fabrics and so the trade off there is going to be how durable those fabrics are.  If you choose this jacket you are likely to be a discerning user who knows and accepts that additional care will need to be taken - but don’t expect the shell to hold up to the kind of hard abuse a different jacket might cope with.  

I was a little worried that the thin fabric would allow down to escape but infect I’ve had absolutely no problems with this at all.  The thinner fabric also ensures the Infinity G will pack up extremely small and the jacket comes with a lightweight stuff sack.  You save on pack size and pack weight.

There have always been two big disadvantages with down.  The first being that it doesn’t cope well with moisture.  It would work well for cold dry conditions and yet, for damper environments, you would traditionally really want to look at synthetics.  This problem has been greatly aided by the introduction, a few years ago, of hydrophobic down.  This refers to a treatment applied to the down which, while not making it waterproof, at least greatly reduces the absorption of moisture.  

I have used a broad range of products with hydrophobic down and am absolutely convinced of its effectiveness and so, if budget allows, I would never recommend anything else.  Suddenly a jacket of this type is a viable choice for damp cold environments like Scotland.  

Having said that, hydrophobic treatments are, at the end of the day, a chemical mixture applied to the down and no chemical is a good environmental choice.  Even more than that, some down treatments use fluorocarbons (CFC’s) which are highly damaging.  Rab are a responsible producer keen to help the environment in any way possible and some time ago they teamed up with my favourite proofing product manufacturers Nikwax to produce a Flourocarbon free down treatment.  Bravo to Rab and Nikwax - this is a great step forward for hydrophobic treatments.

I did say there were 2 big disadvantages with down and the second is the fact it is a natural product coming from living creatures.  Practices like mistreatment and live plucking of birds is something that might be going on and yet consumers won’t be aware of it in the end product.  We generally need to rely on the manufacturers who use the down to keep a check on how their suppliers obtain the feathers.  

Rab are again leading the industry in ensuring their down comes only from European farms that meet the Responsible Down Standard (RDS).  This ensures the down comes from birds that have been treated well by following the chain of custody from farm to product.  I would urge anyone to only choose down products that meet this standard.       


Put simply, the Rab Infinity G is the best down jacket I have ever used.  I can’t believe how warm it is considering its remarkably low weight and pack size.  The addition of responsibly produced hydrophobic down massively increases its versatility and it is also a great looking garment.  It is a fantastic jacket in keeping with Rab’s proud history of producing cutting edge down products designed for Alpinists and climbers.  It is, at £320, a premium product, but if your budget can stretch to it and it suits your requirements, please go for it - you really won’t be disappointed.

Posted by Paul

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