Rab Muon 50 Backpack Review: The days of compromising comfort for lightness are over. A lightweight backpack with everything a thru-hiker needs

Rab which has been steadily expanding its lineup for light and fast mountain activities recently , has once again released a lightweight backpack this season that can only be described as amazing. This time, we tried out the Rab Muon 50 (or Rab Muon 40 ) on some spring mountain climbing and hiking trips, and here is our review.

Key Features of the Rab Muon 50 Backpack

The Rab Muon 50 is a lightweight, large backpack (also available in a 40L size) that minimizes weight without sacrificing the durability and comfort required for backpacking. It's crafted from lightweight, durable, and UV-resistant Spectra® ripstop fabric. Rab's unique TRI-FLEX™ carry system, featuring an aluminum frame for breathability and cushioning, provides comfortable carrying and excellent stability. Equipped with a large front stash pocket, side stash pockets for easy access without removing the pack, and a variety of attachments, it offers numerous convenient storage options despite its light weight. Designed for long-distance, high-speed travel, the Muon 50 offers everything a lightweight backpacker needs for fastpacking, long-distance thru-hikes, overnight trips, and weekend mountain climbs. Its comfort and ease of use redefine conventional lightweight backpacks.

Favorite points

• Cushioning, breathability, fit, load capacity, stability, and all other aspects of this bag provide a high-class carrying experience
• Unbelievable lightness despite its premium comfort
• Lightweight and strong fabric material
• Easy-access side stash pocket for excellent storage
• Functional storage that allows you to pack everything easily and conveniently, including hydration, trekking poles, tents, mats, and small items
• Not too expensive

Points of concern

• The outer front and side stash pockets are loose and don't close properly
• No direct access to the main compartment
• The back length cannot be adjusted

Main specifications and evaluation

Detailed Review

Material, weight, and durability: Lightweight and strong fabric containing Spectra® fiber, an ultra-lightweight, highly durable fiber also used in military applications

At first glance, the fabric used for the body of the Muon 50

, Spectra® fiber, developed by Honeywell . It's said to be "one of the strongest and lightest materials in the world," a high-strength fiber that's 15 times stronger than steel by weight. It's also said to be "40% stronger than aramid fiber, a fiber known for its strength," but to be honest, many people might not understand that. However, when you hear that it's also used in the US military for bulletproof vests, helmets, and armored vehicles, the incredible strength of this new material becomes even more comprehensible.

In fact, even if you dig your fingernails into the smooth surface or rub it against a rock, the surface does not fray at all, does not get a single scratch, and it remains stable in the range of normal mountain climbing. It is also resistant to dirt and UV rays. For reference, the official video below shows some footage of this

is so light that it floats on water, yet has excellent abrasion resistance, flexibility, fatigue resistance, UV resistance, cut resistance, and is also resistant to temperature changes.Muon combines durability that allows it to be used in harsh fields without worrying about damage, with a thinness and lightness that does not hinder easy movement.

Incidentally, the official weight of 995g for the 50L size is actually not that light in the context of a full-fledged ultralight, so if you're looking for absolute lightness, it may not be enough. Rab has taken this into consideration from the beginning, and their claim for this pack is that "lightness is of course an essential element for a fastpacking backpack, but what's important is not extreme lightness at the expense of everything else, but overall practical lightness that includes strength, comfort, and ease of use."

Comfort and stability: The harness structure provides a snug fit and excellent stability

A common problem with backpacks that emphasize lightness is that they are indeed light as a result of being stripped down to an extreme extent, but because they were never designed to carry heavy loads, they are not designed to support the load in the right places (or they require special techniques or experience to make the weight as light as possible). Although this is becoming less common these days, many people still have to sacrifice comfort in exchange for lightness when using such backpacks

I've been used to a lot of packs that looked good but disappointed me when I tried them on, but Muon was different. Despite being a lightweight backpack, its sturdy back structure and moderate cushioning and ventilation make it comfortable and less tiring, and it's stable and less likely to shake even when carrying heavy loads. Just because it's light doesn't mean I have to sacrifice comfort. The secret to this incredibly reliable comfort is, of course, the unique back structure, the TRI-FLEX™ Carry System .

The U-shaped aluminum frame and horizontal frame are combined to create a rigid structure in both the vertical and horizontal directions

The inside of the backpack is equipped with a removable tubular aluminum frame that turns at the shoulders to widen and connects to the bottom in a U-shape (see photo below). This frame acts as a support for the pack, properly transferring the load to the hip belt, reducing strain on the shoulders and bringing the center of gravity closer to the body

In addition to this, a non-removable horizontal frame is built into the center of the back panel (this is a unique feature of Rab that sets it apart from other packs). This horizontal frame not only reinforces the load-bearing capacity, but also prevents the back from curling up due to the load, which can make the pack uncomfortable to wear (see photo below)

The back is equipped with quick-drying padding that curves to fit the contours of the body, keeping the bag flat and snug against your back (see photo below)

The areas around the shoulders where sweat tends to accumulate are made of highly breathable and quick-drying 3D mesh, and the shoulder harness is padded with high elasticity to withstand heavy loads, making it firm, sturdy, and comfortable, making it hard to believe that this is a lightweight backpack (see photo below)

The shoulder harness has a yoke-connected design that distributes the load evenly and increases the durability of the strap base. It also has a load lifter at the shoulder, which naturally brings the center of gravity closer to the body and prevents the upper part from shaking (see photo below)

Vest-style shoulder straps are not only convenient but also provide excellent load distribution

The shoulder straps are wide and equipped with mesh pockets, adopting a so-called "vest-style" design inspired by trail running (see photo below). While this has become commonplace in large-capacity fastpacking models recently, from experience, if not properly designed, the straps can be weak and dig into the shoulders, reducing comfort, making it a double-edged sword if not carefully considered. However, the Muon 50 offers an ideal marriage of a solid back structure that properly transfers the load to the waist and a comfortable, convenient chest area that fits well, eliminating any sense of its vest-style disadvantages.

Waist harness and reverse-pull hip belt provide excellent stability and a snug fit around the pelvis

The quality of the product is already impressive enough up to this point, but the highlight is the waist harness and hip belt, which combine stability and comfort to an incredible degree

The waist harness, which is directly connected to the frame, transfers the weight of the pack to your waist without any loss, and the three-dimensional mesh cushion is thin but provides minimal cushioning, and the buttocks, where weight is concentrated, are well padded (see photo below)

The hip belt that fastens the waist harness is connected to the stash pockets on both sides, tightly wrapping the pack around the pelvis from the sides (see photo below)

Not only is it comfortable to wear, but the pack doesn't twist or sway sideways, and its high stability is immediately apparent when you put it on. Incidentally, the hip belt pull tabs are reverse-pull, meaning they're pulled forward (easy to pull) rather than outward (difficult to pull), making them easy to adjust

Storage capacity and ease of use: It's not just the bare minimum. It has ample storage and convenient parts that won't make you feel any inconvenience

The Muon 50 has numerous pockets and attachments strategically placed for ease of access and efficiency.

The variety of items available is not something you can underestimate just because it's a lightweight backpack; in fact, it's almost comparable to a regular hiking backpack

Not only does it have plenty of storage space, but it is also smartly placed so that you can quickly access it when you need it while on the move, and practicality has been carefully considered for use in fast packing

Main storage

the Muon 50 is a drawstring type similar to a typical mountaineering pack, with an easy-to-open and close entrance, a single-fastening strap, and a removable rain cover (approximately 10 liters in capacity) for a simple design.

It would have been even better if there was a direct access zipper that would allow you to access the contents without opening the rain cover, but there is plenty of external storage so perhaps that is asking for too much

On the other hand, if you're aiming for even lighter weight, a roll-top design might have been better. However, with a large-capacity pack, it's hard to sacrifice the versatility of storing a rain cover, so this is an area where opinions may differ. The Muon 40 , completely omits the rain cover and has a roll-top entrance, making it more suitable for a lightweight backpack.

This is pretty much the only difference in specifications due to the difference in capacity (the body size and construction are roughly the same), so if you don't mind a roll-top design, the 50-liter model is more convenient as it can accommodate a wider range of luggage amounts (which is why I chose the 50-liter model)

Front and back pockets on the rain cover

As mentioned above, the top of this pack has a rain cover with a large zippered pocket. This pocket has a large opening, making it easy to access and store various small items together without worrying about size (see photo below)

Furthermore, the security pocket with key clip located on the underside of the rain cover is made of mesh fabric, making it easy to see the contents, so it may be easy to store not only wallets and key chains, but also medical and emergency items that you want to access quickly. This pocket, which I usually don't think is very useful, has suddenly become much easier to use (see photo below)

This rain cover and the straps for the rain cover are removable, and eventually the rear aluminum frame can also be removed. The weight of the pack can be customized to some extent depending on the amount of luggage (see photo below)

Large front and side stash pockets

The large front stash pocket is stretchy yet reinforced with durable Spectra® fiber, making it tear-resistant and secure. It can hold a rain jacket, snacks, sandals, water bottles, filters, trash bags, and other large items (see photo below)

My personal favorite are the side stash pockets, which are also made with a hybrid structure of stretch mesh and Spectra® fiber, making them resistant to abrasion

It's also large enough that I could fit a Nalgene bottle and a 500ml PET bottle with room to spare. The opening is also angled, so I can access the bottle while standing, and the side straps allow me to secure long items, making this a truly excellent pocket that meets most of my requirements for a side pocket (see photo below)

However, one thing that bothered me, despite its convenience, was that both the front and side stash pockets have loose openings (is this intentional?), so while it doesn't bother me when there's something inside, they tend to open up a bit sloppily when there's only a little (or no) luggage inside (see photo below). The side pockets in particular are left loosely open, so snow and other debris will likely find its way in before you know it

The only saving grace is that there is a compression drawcord inside the pocket, which helps to secure the contents to a certain extent. It's a blessing in disguise that the contents didn't spill out. That said, I'm a little disappointed that they could have tightened the elastic a little more to close the opening more firmly from the start, or added a drawcord to make it perfect (since the overall design was pretty close to ideal)

Shoulder strap pocket

The best thing about vest-type shoulder straps is that they allow you to place large, convenient pockets in the most accessible areas. The Muon 50 has zippered mesh stretch pockets on both sides of the shoulder straps (see photo below).

They come in a wide variety of shapes and capacities, and the zippers allow for safe storage and quick access to a variety of items, including soft flasks, smartphones, gels, snacks, maps, compasses, and sunscreen

It would be difficult to fit a plastic bottle in it, but there are large side stash pockets on both sides, so you can put the plastic bottle on the side instead of in here and it will be fine

Trekking pole attachment

The external attachment for trekking poles includes one removable cord lock on the front suitable for long, retractable trekking poles (see photo below)

In addition, the bottom of each shoulder strap is equipped with a cord lock that allows you to store trekking poles, including foldable ones, like a samurai's sword, making them easy to quickly take out and put away while on the move (see photo below)

Hydration compatible

The hydration sleeve and clip, as well as the opening and closing point for the hydration hose, are all securely located inside the main compartment (see photo below)

Bungee cord loop

There are discreet webbing ladder loops along the sides and bottom (see photo below) and on the top of the rain cover, which can be used to attach carabiners or bungee cords. This allows for flexible use, allowing you to add attachments as needed, or hang slightly wet items on a carabiner to dry as you walk

Plenty of compression straps that can be adjusted to fit the amount of luggage you are carrying

The pack also features ultra-lightweight compression straps (drawcords) at the bottom, which can be tightened to prevent the pack from moving when carrying a small load (and these drawcords can be adjusted while wearing the pack). These compression straps also function as storage, making them ideal for securing mattresses, tents, etc. (see photo below)

Of course, there are also compression straps on the sides for when you have less luggage. These straps are well-made, allowing for wide compression in two directions, and they also feature a smart buckle that allows you to tighten both directions with a single buckle (see photo below)

Summary: A masterpiece backpack for fastpacking that is light, strong, comfortable, and easy to use, with no compromises

Rab Muon 50 Backpack

created by Rinker

• Amazon
• Rakuten Market

Having tried out a variety of backpacks over the past few months, I've come to realize that the Rab Muon 50 , but also extremely durable, with exceptional comfort and functional storage. It's a masterpiece of exceptional refinement and sophistication, even among the many lightweight backpacks that have sprung up in recent years due to the surge in popularity of fastpacking. While there were certainly some concerns, as mentioned in the article, most of them were minor and not insurmountable. However, the lack of adjustable back is something to be aware of, and unless you choose the right size, you won't achieve the ideal comfort. At 176cm tall, the regular model fit me perfectly, but shorter men and women might want to consider the "ND" model.

From the perspective of weight and design, it may not appeal to stoic UL hikers who aim for the lightest possible weight or hikers who want to enjoy the UL style, but I think it has the potential to be well received by fastpacking beginners who want to enjoy long trails as an extension of mountaineering or hiking, as well as a wide range of light and fast-paced hikers who prioritize practicality and comfort.By the way, the price is also quite reasonable for this type of backpack

In any case, it's rare to find a lightweight backpack that achieves such high levels of functionality in all its elements. With this backpack that I can rely on in every way, I feel like I can comfortably get through tough multi-day journeys on long trails

   

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