Rab Khroma Ascendor Pants Review


Our Rab Khroma Ascendor Pants review examines a tough ski mountaineering orientated trouser with advanced materials and ski focussed features.  We hope you find it useful.

Ski Touring at Grand Montets


Rab now offer a full range of ski mountaineering focussed clothing.  Hardshell tops and bottoms, insulation layers, gloves and packs – they have everything available.  We have used a selection of their products including their Khroma Goretex Pro jacket and pants, their Khroma Tour gloves and Khroma 22L Ski Pack (our review of that pack is here). It is a carefully designed and comprehensive range. 

Our Rab Khroma Ascendor Pants review explores what Rab describe as their ‘definitive ski mountaineering pants designed for pushing your limits in the backcountry’.  Please read on to find out what we think of these soft-shell pants.

Thigh Pocket (with security clip)


The Khroma Ascendors are made from mid-weight and weather resistant Matrix softshell fabric.  Matrix is a 2 layer bonded 235gsm fabric said to offer stretch, breathability and durability.  It also offers a high level of sun protection.

The pants have tough kick patch reinforcements around the lower legs and a zipped ankle gusset to widen the hem for ski boots.  This zip also helps access the elasticated internal snow gaiter.  A diamond gusset panel and articulated knees aid mobility and range of movement.  Critical seams are taped for strength and protection. 

Ankle Gusset

Khroma Ascendors are designed with a regular cut and high elasticated waistband for a harness compatible fit.  They have a YKK zip fly, detachable braces, velcro waist adjustment and belt loops.  There is zipped ventilation on both thighs. 

They have YKK zipped and mesh lined side pockets, a YKK zipped rear pocket and a further YKK zipped thigh pocket with internal security clip. This thigh pocket also includes a stretchy internal storage pocket which is ideal for further securing a phone, transceiver or other small items.  

Ascendors weigh 729 grams (25.7oz) for a size medium and have a retail price of £210.  They are available in the black (Ebony) colour tested and a mustard colour called Footprint.

Braces & Velcro Waist Adjusters

In Use

The conditions ski mountaineers face on a typical day out vary hugely.  We all hope to be out on the bluebird days, but inevitably in winter weather we can face anything.  But, of all the layers we might take,  it is soft-shell fabrics that usually work for the broadest range of conditions.  Softshell layers will help insulate, protect from wind, allow an excellent range of movement and keep out a reasonable amount of moisture.  This works for upper layers, but for pants too.  With all that in mind, for the average ski mountaineer something like the Khroma Ascendors are sure to get plenty of action.

Alternative Uses

However, their usage range has also turned out to be much broader.  We often use skis as a way in to ice and mixed climbing routes, and so a pair of softshell pants that climb well is important.  So, although we are testing these for their intended use, we will factor in their climbing qualities too.

Long Thigh Vents

Regular Fit 

The fit of the Ascendors is, as described by Rab, regular. Paul has been testing these and asked for a size medium. This is described as being for a 32” waist.  As a 31-32 waisted person, they are a comfortable and yet relaxed fit. The sizing allows base layers to be tucked inside and the fit through the legs allows for base layers underneath if desired. If they are a slightly looser fit it is easy to adjust the waist with the velcro tabs and the braces will keep them where they need to be.  

The combination of the stretchy fabric and the clever cut ensures the Khroma Ascendors offer complete freedom of movement.  They are exceptional.  The articulated knees also means there is no problem with high steps.  The fabric has also proved to be very durable.  It has shrugged off mixed routes and any skiing activities with ease.  This is helped by the durable ankle protection.  Rab don’t identify what fabric this is made from, but it is certainly up to tough use.

Side Pockets (with mesh ventilation)


Ski mountaineers face a range of temperatures.  When heading uphill you will be working hard and producing a fair amount of heat and moisture.  To stay comfortable for this you need breathability.  The Matrix fabric breathes really well.  This breathability is also aided by the option of the long thigh venting zips and mesh lined side pockets.  

Of course, when you are heading downhill it is usually keeping the temperature in that’s important. With thin base layer pants underneath the pants have faired really well even with temperatures down to around -8 Degrees Celsius.  Similarly,  clothing of this type also need to be windproof.  Again, the Ascendors have proved their ability to fend off wind effortlessly.

Ice Climbing In The Khroma Ascendors


Similarly, the moisture resistance of the Ascendors has been well tested on dripping ice routes and in snow storm conditions.  No softshell is going to compare to a hardshell level of moisture protection, but you will likely find these pants cope in a surprisingly wide conditions range.  Depending on weather conditions, with these on board we have often not bothered carrying additional hardshell pants.

Thigh Vent and Logo

Ankle Gusset

The fit of the ankle gusset is perfect.  It should fit over any ski mountaineering boots and still be zipped closed (we obviously can’t speak for all boots, but as shown in the photo it fits over something like a Scarpa Maestrale with ease).  Even if your boots can’t fit over the ankle gusset, the zipper allows extra room for boots to extend out of the side if needed.

The zipper is also very useful for easy boot on and off and to adjust the built in elasticated internal snow gaiters.  It might even be used to offer a bit of extra ventilation when skinning.   


The pockets are generous and well placed.  The thigh pocket is great for storing items like a phone or transceiver.  The useful internal clip also allows a transceiver to be secured with a tether.  There is plenty of other storage available for snacks and other smaller items in all the other pocket options.

Reinforced Lower Leg


Rab lead the industry in sustainable manufacture. For example, their Material Facts programme (they are the first apparel/equipment company to do this) allows potential purchasers to understand the make up of every component of the product they are considering. Details of this system are available on their website here.

The material facts for the Khroma Ascendors, however, say the pants only features 3% recycled materials. Many of their products have a much higher recycled content, but this obviously depends on the fabrics available. The thing that also makes a huge difference to environmental impact is the hard wearing build of a product.  If we can all find products that will last a long time we inevitably create less of an environmental imprint.  The Khroma Ascendors certainly tick that box.

Ankle Gusset & Gaiter


As our Rab Khroma Ascendor Pants highlights,  these are a really great option for ski mountaineers.  The pants are really well designed, have all the features needed for their intended uses and perform superbly. So much so, that on a recent winter Alpine trip they were Paul’s go to option every single day.  They toured well, protected effortlessly and had every feature we need for mountain days on skis.  An added bonus is how efficient they have been for winter climbing too.  We highly recommend this excellent addition to the Rab ski equipment range. Full details on the Rab Khroma Ascendor pants are available on the Rab website here.

We hope you found this Rab Khroma Ascendor Pants Review useful.  We have a long history of using Rab products and there is a range of recent Rab reviews available on our website review section here.  Examples include our review of their Ionosphere Sleeping Mat is here and their Kinetic Ultra Jacket is here.  We also tested their Mythic Ultra Jacket here . We also test products from a selection of other companies and they are all available on the review section of our website here. Please do take the time to have a browse.