Back in the late nineties Mark Twights forward thinking volume ‘Extreme Alpinism’ hit the shelves. Among his many ideas was the concept of over layering for extra warmth. Prior to this innovative idea the general plan for adding a layer was to remove your gloves, loosen your harness, remove your shell, put on your extra warm layer, shell back on etc, a real faff.
Twights' simple idea was to layer a synthetic insulated jacket over your shell when you needed to boost the warmth of your clothing system. Unlike down, synthetic insulation retains a lot of its thermal properties when wet meaning it doesn’t need protecting from the elements. Fast forward to the current day and the concept of a belay jacket has spread across the worlds mountains and in particular to the demanding world of Scottish winter climbing.
Rab® were one of the first brands to produce a dedicated belay jacket and my original is still going strong after years of abuse. It has a lot of ‘character’ now but fundamentally it still does an amazing job of keeping me warm when the environment is determined to make me wet, cold and miserable.
There are two fields of thought in belay jacket design. One is to go as lightweight as possible with minimal features. It’s all about lightweight maximal warmth for belaying or emergency situations.
The second option is to build a robust technical jacket with plenty of features. This gives the user more survivability and also allows the garment to be used for climbing when conditions are really bad. The latest incarnation from Rab falls into the latter category. The Photon X Jacket is a great looking technical jacket packed full of features - multiple big pockets, reinforced patches, reflective detail, stiffened hood visor and plenty of warmth.
In the last 6 months I’ve worn it to the summit of Antarctica’s Mount Vinson, photographing Emperor penguins on the Weddell Sea, running film safety on a Lake District hillside and on a diverse range of Scottish winter mountain days. Early season conditions in Scotland have been challenging and perfect for hypothermia with the freezing level up around the summits. It’s a bit of a standing joke that the community of mountaineering instructors who work the Scottish winter season measure how bad the weather has been by the number of pairs of gloves they get through in a day. Needless to say there have been a number of 6 glove days in 2017. However, I’ve been very comfortable in the depths of my Photon X. In the worst of conditions it’s great to be able to sink down into the insulated collar and try to hide. The hood goes up and stays up with minimal adjustment and the pockets will swallow a whole picnic of supplies.
The level of insulation is just about perfect for Scottish winter climbing. I’ve warmed up quickly whenever I’ve over layered with it, but interestingly I’ve never felt like overheating when navigating off in a hoolie. It even dries overnight in my unheated campervan so it’s ready to go in the morning, even if I’m not!
Overall a very impressive piece of kit for Scotland and further afield. Bad weather is very much part of the mountaineering game but this is a very useful tool in successfully operating in it.
Synthetic duvet jackets have been a mainstay of my clothing system since becoming a realistic alternative to fleece back in the late nineties. I've used and abused a number of jackets from ultra-lightweight pieces to full expedition parkers and even insulated trousers in polar regions.I’ve found that Primaloft clothing offers a lot of protection and survivability for their weight. They are wind and weatherproof but also keep you warm when wet, which is essential for our typical UK weather.
The latest incarnation of the Xenon-X Jacket had a baptism of fire last month. I teamed it up with the lightweight Vapour Rise Jacket for the variety of different days inherent in being a mountain instructor - from chilly belays while guiding on a Lake District mountain crag, to a soggy day taking photos of a mountain event. It’s been used as a lightweight warm layer for a very windy mountain marathon and as a stunning bivi, high above Chamonix while introducing friends to the delights of alpine climbing. It provided instant warmth after an open water swim under a full moon and spent several days stuffed into the bottom of my rucksack as an emergency layer while instructing.
The new Primaloft Gold Active is slightly less warm weight for weight than its predecessor but it’s more robust matted composition means that the jackets lining fabric can have a more open weave and therefore greater breathability. This becomes very obvious the first time you work up a sweat. Normally I'd be venting a synthetic jacket and removing hats and gloves to avoid overheating, but the Xenon-X was comfortable across a wider range of activity, quickly wicking moisture and heat away, which also meant I didn't get cold and clammy when I stopped moving. Despite its low weight it feels reassuringly warm and will easily layer over or under my shell.
Rab® have kept it simple with a couple of hand-warmer pockets and an internal chest pocket which will take a map or guidebook with ease, while the under helmet hood is extremely comfortable and useful.
Many lightweight fabrics are prone to getting jammed in zips, however with the Xenon-X the wind baffle behind the teeth has been slightly stiffened providing the perfect balance between zip jam prevention and minimal weight and bulk.
Practical as a summer and winter climbing layer, this jacket is becoming my go to option for UK instruction and guiding. It ticks all of the boxes that a lightweight synthetic jacket should but introduces an element of flexibility. I look forward to putting the Xenon-X through it’s paces in Antarctica at the end of this year. I’ll report back on how it holds up!
Member of the Rab & Lowe Alpine Test Teams & former reviewer for The North Face