Review of the Rab Ascent 900 XL/Long Sleeping Bag

by the bald scrambler

Published By: Daniel Woodley. Updated: 7th March 2024. Filed at: Reviews. Disclosure: I earn commission from purchases made via links, read more.

I’m a big guy at 6ft2″ and with my broad shoulders and over-breakfasted stomach, I often struggle to fit comfortably in winter sleeping bags.

I tried the regular Rab Ascent 900 sleeping bag last winter and while it was a little short, I also found it very tight along my shoulders and waist areas.

This winter I sold the regular Ascent 900 and purchased a brand new XL/Long version (for men).

The sleeping bag has the word “XL” written on it but the cardboard tag has “Long” rather than “XL” on it. On most websites that sell this bag, it’s marketed as the “Long” version but as far as I know they are both the same bag.

Here’s a photo:

Rab Ascent 900 label

Comparison to the Regular Version

Here are the key differences:

Length: 230cm/90in compared to 215cm/84.6in for the regular version.

Max user height: 200cm/6ft6in compared to 185cm/6ft for the regular version.

Internal foot girth: 110cm/43.3in compared to 108cm/42.5in for the regular version.

Internal hip girth: 136cm/53.5in compared to 134cm/52.8in for the regular version.

Internal shoulder girth: 162cm/63.8in compared to 160cm/63.0in for the regular version.

Total weight: 1610g compared to 1530g for the regular version.

In a nutshell, the Long/XL version offers 15cm/5.9in of extra length and 2cm/0.8in of extra girth at the foot, hip and shoulder.

The pack size is roughly the same for both bags as both compress down to fit into the storage bags.

The fill ratio is also the same for each bag and the extra weight is negligible.

Note: The Long/XL version is currently only available with the left zip.

What’s Included:

This is what you get included:

1 x Rab Ascent 900 XL/Long sleeping bag in Oxblood red.

1 x small bag for travelling.

1 x larger/looser vented bag for long-term storage at home.


Orange large storage bag

Large vented bag for long-term storage

Rab 900 storage bag

Smaller bag for backpacking/hiking etc

Rab Ascent 900 label


Rab Ascent 900 Long/XL sleeping bag

Note that this “mummy” sleeping bag is a loose fit compared to some hugging bags. I found there was plenty of room to move my legs around (for a mummy bag).


  • Warmth: I found this perfect for winter wild camps in Snowdonia and the Lake District.
  • Extra legroom: While 2cm of extra leg girth may not sound much, I found it made the difference between being too tight and just right. The extra 15cm of length was perhaps a little too much for me (I’m 6ft2) but I have no complaints.
  • Lightweight: At 1610g, this bag is far lighter than my summer sleeping bag which weighs over 2kg and offers only a fraction of the thermal performance of the Rab 900.
  • Low depreciation: Rab is a respected brand and these bags can be professionally cleaned and sold on eBay should you decide that winter camping isn’t for you.


  • The price: I paid £306 for this bag (inc delivery) and while the regular version is often discounted (esp out of the winter season), this XL/Long version is usually sold at full price. I checked online prices from Sept-Dec 2023 and never saw a UK price below £300.
  • I found it slippery on both of my winter sleeping bags and I kept sliding off during the night. Some extra grippy materials on the underside of the bag would have made for a better night’s sleep on the uneven mountain terrain where I wild-camped.
  • The packed size is quite large (see photo) and it took up a ton of space in my rucksack.
Length of the storage bag

Approx 400mm/15.5″

Width of storage bag

Approx 250mm/10″

My Experience With the Rab Ascent 900

I tested this bag during a 2-night wild camp on the slopes of Snowdon in Wales, United Kingdom in March 2024.

The nighttime temperature was forecast to be around -7°C with a windchill factor of -11°C (I was inside a winter tent which kept out much but not all of the wind).

Weight/Packsize: I found that the weight of 1610g was acceptable for a large winter sleeping bag but the compressed size was still very large and it took up a ton of space in my backpack. The small bag didn’t compress the sleeping bag down to a small size and it was bigger than my inferior Berghaus summer sleeping bag.

Long-term Storage: The Rab 900 comes with a loose/large vented bag for long-term storage and this is a nice touch as I know down sleeping bags should never be kept compressed for long periods of time as it affects the performance of the material.

Comfort: Overall, I would say that this is a great sleeping bag for winter wild camps etc, even for taller people. My only complaint was the slippery material which caused me issues on my slippery sleeping pad which was on a slight incline (finding perfectly flat ground on a mountain isn’t always easy). The Rab 900 XL is quite roomy compared to many other “mummy” bags and there’s certainly space to move the legs around.

Warmth: I was fine during the night although I did keep my winter leggings and long-sleeve thermal top on as well. Also, I was sleeping on top of a 7.3-rated winter sleeping pad which insulated the underside of the bag very well.

Features: This bag has a neck and zip baffle to keep out drafts and comes with YKK zippers which are one of the best brands. The hood and the neck can be tightened with the drawstring cord to keep the warm air in the bag. There’s also a zipped pocket for storing small items such as a wallet, phone or keys.

Hood on the Rab Ascent 900 XL

The hood and neck are well insulated and have cords to close the space and seal in heat.

Pocket for storage

Pocket for storage.

Size at the neck and shoulder area

Width at the neck/shoulder area.

Size at the foot area

Width in the footbox

I Recommend

I recommend this Rab Ascent 900 XL/Long sleeping bag to those who are:

  • Above 6ft2″.
  • Prefer a little extra room in their sleeping bag.
  • Camping in conditions down to minus 15°c or so (I wouldn’t lower than this without extra layers).
  • Have a good quality sleeping pad rated to 6.0 or above.
  • Are okay with the weight and pack size – this isn’t a lightweight bag and certainly isn’t compact either.

If you are new to winter camping – You should know that the sleeping pad is probably more important than the sleeping bag.

When inside the sleeping bag, the weight of the user will compress the insulating material, rendering it very poor at keeping out the cold from the ground. In my opinion, a good quality insulated (6.0 or above) pad must be used to reflect the user’s body heat and also keep out the cold from the underside.

Even a good quality winter sleeping bag can be rendered useless if the insulating material is compressed and there’s no insulating pad underneath. I know from my own experience that a good quality bag and pad should be used in sub-zero temperatures.

Read my review of Thermarest’s best-performing winter sleeping pad. This is what I think of Sea to Summit’s best winter sleeping pad.

Should You Go For The Regular or the XL/Long?

At 6ft2″, I’m right on the limit for the regular Rab Ascent 900, I can fit into it, it’s just the XL is slightly more roomy, especially lengthways.

If you’re taller than 6ft2″, I 100% recommend the XL/Long version but if you’re 6ft1″ or shorter, I think you’ll be okay (certainly lengthways) in the regular sleeping bag.

We are all built differently so it might be worth trying the bag in a shop if you can or buying early with plenty of time so you can return the bag for a swap/refund if it’s not a good fit.


The OEX Leviathan EV 900 is about £120 cheaper and has a similar amount of fill power but I know someone who has this bag and he said it’s not as warm as the Rab Ascent 900 and the feathers spill out everywhere.

The Rab Ascent 1100 is the top of the Ascent range and can be used down to -25c but having seen this on display in a shop, I can say it’s huge and very heavy at 1725g. Personally, I think this is overkill for most UK winter camps.

About Daniel Woodley

This review of the Rab Ascent 900 sleeping bag was created by Daniel Woodley, aka The Bald Scrambler.

From walking along beaches and kayaking down rivers to making his way up mountains and even jumping out of planes, Daniel has a love of the outdoors but scrambling is his real passion.


Daniel Woodley

Daniel Woodley aka The Bald Scrambler

Have fun, keep safe. Hopefully I’ll see you on the mountains one day

By The Bald Scrambler

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