Rab Ascendor 45 Review: Six Months in the Lake District

I have been using the Rab Ascendor 45 since the beginning of summer 2026, taking it across the fells around Eskdale, up Scafell and on a number of scrambling routes throughout the Lake District. During that time, it has carried everything from my usual mountain walking equipment to heavier loads approaching 20 kg, and has accompanied me on days lasting up to eight hours.

Living in the Eskdale Valley, I am fortunate to have some of England's finest mountain terrain on my doorstep, which means my equipment gets plenty of opportunities to prove itself. Over the years, both through my military service and my own outdoor pursuits, I have spent a considerable amount of time carrying heavy rucksacks in some fairly unforgiving environments. I know from experience that what feels comfortable for the first hour can become a very different proposition several hours later, particularly when the ground becomes steeper and fatigue begins to set in.

It is with that experience in mind that I have been assessing the Ascendor 45. I was not looking for something particularly complicated, just a dependable mountain rucksack with enough capacity for my equipment, comfortable enough for long days and practical when the weather or terrain demands a quick change of plan.

Carrying Comfort

The first thing that struck me about the Ascendor 45 was how comfortably it carries a substantial load. I generally head out with around 15 kg, although there have been occasions when I have carried closer to 20 kg, and at no point have I experienced the sort of shoulder discomfort I have come to associate with some other rucksacks.

On my longest outing, which lasted around eight hours excluding stops for drinks and lunch, the pack remained comfortable throughout. What particularly impressed me was how balanced it felt. There is nothing worse than negotiating uneven ground with a rucksack that seems determined to pull you sideways or shift its weight every time you change direction, especially when scrambling. The Ascendor has remained remarkably stable, allowing me to concentrate on where I am putting my feet rather than constantly adjusting what I am carrying.

I was also pleasantly surprised by how well it managed moisture against my back. Anyone who spends a reasonable amount of time in the hills knows that a sweaty back is almost inevitable, especially when carrying a heavy load uphill. I have owned rucksacks that have left me absolutely soaked beneath the back panel, yet the Ascendor has been noticeably better in this respect. I am certainly not suggesting that it somehow eliminates sweating, but compared with previous packs I have used, the difference has been significant.

For a rucksack designed with technical mountain use in mind, this combination of comfort and stability has been particularly welcome. It is one thing to create a lightweight, streamlined pack, but quite another to make one that remains pleasant to carry when you have filled it with the equipment you actually need for a day in the mountains.

A Practical Approach to Design

One of the features I have grown particularly fond of is the long zip running down the side of the pack, providing access to the main compartment without having to open everything from the top. It sounds like a small detail, but in practice it has proved extremely useful.

I tend to position my waterproofs or a small flask where I can reach them through this opening. In the Lake District, where the weather can change remarkably quickly, being able to retrieve a waterproof jacket without emptying half your rucksack is a genuine advantage. It is also useful during shorter stops when you want something from inside but do not particularly fancy unpacking everything to find it.

The general adjustability of the Ascendor is another aspect I have appreciated. Rab has provided several ways to configure the pack depending on what you are carrying, including the option to remove the lid. I will admit that I initially regarded the removable lid as something of a gimmick. Having experimented with it, I can see the appeal, particularly for someone wanting a simpler arrangement or looking to reduce the amount of equipment they are carrying. Whether it is something I will regularly take advantage of remains to be seen, but it is a useful option to have.

If I could change one aspect of the design, though, it would be the external storage. I am someone who likes to keep smaller items easily accessible, and while the lid provides somewhere to put them, I would much prefer an additional external pouch or pocket. There is a balance to be struck here, of course. The Ascendor is intended for mountain use, including more technical terrain where unnecessary straps and pockets can become a nuisance. Even so, I think a little more accessible storage could be incorporated without compromising the overall design. It is not something that has caused me any serious difficulties, but it is probably the feature I miss most when comparing the Ascendor with other rucksacks I have owned.

Hydration and Mountain Safety

I prefer to drink regularly while moving rather than waiting until I stop, so having the option to use a hydration bladder and drinking tube suits me particularly well. During the warmer months, this has worked nicely with the Ascendor, allowing me to take a drink without breaking my stride or removing the pack.

There is, however, a practical consideration as winter approaches. Drinking tubes have a habit of freezing in sufficiently cold conditions, particularly when exposed to wind, so I will need to rethink my hydration arrangement for the colder months. It is not a criticism of the rucksack, simply one of those lessons that comes with spending time in the mountains throughout the year.

Another feature that caught my attention was the integrated RECCO reflector. For those unfamiliar with it, RECCO technology uses a small passive reflector that can be detected by rescue teams equipped with a compatible search detector. It does not require batteries and is not something you need to activate.

I like the fact that Rab has included it, although it is important to understand what it does and, perhaps more importantly, what it does not do. It is not a GPS tracking device, it will not automatically alert anyone if you get into difficulty, and its usefulness depends on rescuers having the appropriate equipment. It certainly does not replace sensible planning, navigation skills or the emergency equipment you should already be carrying. Nevertheless, I regard it as a worthwhile addition. Hopefully, it is one feature of this rucksack I will never have to discover the effectiveness of firsthand.

Living with the Ascendor in Lake District Weather

As anyone familiar with Eskdale will appreciate, you do not have to venture particularly far into the mountains to encounter rain. The Ascendor has accompanied me through wet conditions, and so far I have been satisfied with how it has performed.

I should point out that I always keep my equipment in individual dry bags, regardless of what rucksack I am using. It is a habit developed over many years outdoors, and one I consider essential when carrying clothing or equipment that needs to remain dry. Consequently, while I have had no reason to complain about the pack in the rain, I cannot offer a definitive assessment of how well it would protect everything inside if I were not using that additional protection.

I am far more interested in ensuring my equipment remains usable than finding out the hard way whether a rucksack can withstand prolonged heavy rain on its own.

The next proper test will be in winter conditions. I am heading to Ben Nevis for a winter skills course, which should give me an opportunity to use the Ascendor in a different environment and assess some of its more technical features. Although the pack includes ice axe attachments, I have not yet used them, so it would be premature to comment on their practicality. I am particularly interested in how the rucksack handles additional winter equipment, whether the various adjustments remain straightforward when wearing gloves, and how accessible the contents are when conditions are less forgiving. I will update this review after the course rather than make assumptions about performance I have not experienced.

Is the Rab Ascendor 45 Worth the Money?

I paid approximately £140 for my Ascendor 45, and having used it regularly for several months, I consider it money very well spent.

What I have appreciated most is that the rucksack has simply done its job without giving me much to think about. I have not found myself constantly readjusting it, struggling with uncomfortable shoulder straps or wishing I had brought a different pack halfway through a walk. Its design is practical, and the carrying comfort has been consistently good even with the heavier loads I tend to carry.

The lack of another external pocket is my main criticism, and I can imagine that anyone who likes having several smaller compartments might find the relatively streamlined design a little frustrating. Equally, some of its mountaineering-specific features have yet to be tested properly, so I would not pretend this is a comprehensive assessment of everything the Ascendor is designed to do.

What I can say is that, for mountain walking and scrambling in the Lake District, it has exceeded my expectations. Would I buy it again? Absolutely, and without hesitation.

There are plenty of rucksacks on the market offering various combinations of pockets, attachment points and technical features, but ultimately the real test is whether you enjoy carrying one after several hours on the hill. The Ascendor 45 has proved exceptionally comfortable, even with the relatively heavy loads I tend to carry, and that alone makes it worthy of serious consideration. For anyone looking for a capable 45-litre mountain rucksack for long days in the hills, I would have no difficulty recommending it based on my experience to date. Its first winter outing is still ahead of it, and I am looking forward to finding out whether it performs just as well on Ben Nevis as it has on my home ground around Scafell.