A cosy Bikepacking essential from Rab which will boost the temperature rating on your sleeping bag by a few degrees

Product Overview

Overall rating:

Score 9

Rab Thermic Neutrino Sleeping Bag Liner


  • Soft fleecy interior, smoother outer surface slides into sleeping bags easily, compresses down to a small size


  • Could do with a small compression sack, but this is a minimal issue


Rab Thermic Neutrino Sleeping Bag Liner review


Price as reviewed:


Rab’s Thermic Neutrino is a tapered thermal liner designed to fit in the Neutrino range of bags, but just as happy in any other brand’s offering. It’s superbly well made, has genuine eco credentials, and adds a layer of warmth without the bulk. All that helps it slide nicely into our list of the best bikepacking kit in 2022.

There are many reasons to include a sleeping bag liner in your bikepacking armoury, each as important and helpful as the next. Down sleeping bags can be a pain to clean, and you don’t want to be doing it too often for best longevity of the bag, so an easily washed liner can stop oily, sweaty and grubby legs from coming into contact. That, to me, is the number one.

Quick drying and adding a layer of warmth to your sleeping bag, the Rab liner is super versatile

In addition to that it can make for a more flexible sleep system; it allows you to carry a lighter sleeping bag because of the extra warmth it brings to the party. If the evening is chilly, crawl into both, but if you know it is going to be a hot one, then the liner on its own is a great, low maintenance option. Being synthetic fleece it doesn’t care if it gets damp, unlike a down bag, and will dry in the blink of an eye.

Lastly it can be a handy option to pull out if you spend the night drying off in a hostel.

Soft brushed interior fleece was a welcome haven at the end of a hard day on the bike, but we also appreciated the outside face of the fabric being smoother, and consequently slightly harder wearing. It was also easier to slide into sleeping and bivvy bags and wouldn’t catch on other zips as easily.

The Rab liner packs down small enough to fit in most bikepacking bags

With its hardy nature I tended to pack it into the less used corners of the bikepacking bags, using it to fill the narrow end of a seat pack, and it never suffered for the treatment. If you did want to pack it in a bag however, it definitely compressed far smaller than the supplied 19x14cm stuff sack, so a small compression sack would be useful.

Rab is very active in the sustainability stakes too, using a high percentage of recyclable materials and being a certified climate neutral company for the last three years. It has just announced a global programme of upcycling off-cuts and recycled fabrics, using them to repair kit. So not only could you extend the life of your current gear by repairing it rather than replacing, it could be done using environmentally friendly options. Hats off to them.


Inside a bivvy bag we felt it was easily warm enough for a summer night out on its own, provided the temperature didn't sink unseasonably low. Added to a sleeping bag it would easily bump the temperature rating by a few degrees, meaning you could pack a smaller sleeping bag. That’s useful because two smaller bags rather than one biggy makes for more flexible packing.


Weight:370g (with stuff sack)
Size:185cm long x 82cm max width
Packed Size:19cm x 14cm dia.