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CamelBak M.U.L.E. 12l bag review

Can the 24-year-old M.U.L.E. compete with fresh blood?

Our rating 
3.5 out of 5 star rating 3.5
GBP £109.99 RRP | USD $110.00
CamelBak M.U.L.E. 15l mountain bike backpack

Our review

A good, lightweight pack that’s comfortable to wear most of the time but could do with some enhancements
Pros: Lightweight and easy to get comfortable; plenty of storage compartments; fantastic 3-litre bladder included in the price
Cons: Can bounce over bumps and rough terrain; helmet mounting options are limited and it fills up quite quickly, especially with a full bladder
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The M.U.L.E. is widely regarded as one of the original riding packs, and CamelBak’s brand name is now as interchangeable with bladders as Hoover is with vacuum cleaners.


But as one of CamelBak’s longest and best-selling packs – first launched in 1996 – how does the M.U.L.E perform against its modern counterparts?

CamelBak M.U.L.E. 12l backpack specifications

CamelBak M.U.L.E. 15l mountain bike backpack
The shoulder straps could do with being wider.
Simon Bromley

Built with four separate compartments the M.U.L.E. has plenty of space to store everything you need on a ride.

In the front-most compartment there are internal organisers with enough space to store pumps, tubes and tools. There’s also a separate zipped pocket.

The next compartment doesn’t have organiser sections but does contain the sleeve for the third, smaller pocket that’s accessed from the exterior of the bag.

The fourth pocket is designed exclusively for a Crux 3-litre bladder that’s supplied with the pack.

CamelBak M.U.L.E. 15l mountain bike backpack
There’s a good selection of internal organisers.
Simon Bromley

As well as plenty of storage, there are adjustable shoulder, chest and hip securing straps, and on the outside of the pack there’s a stretchy mesh pocket and strap clips to attach helmets with.

There are reflective accents on the rear of the pack and the straps, too.

CamelBak M.U.L.E. 12l backpack performance

Even full of kit for a day’s riding there’s plenty of room and enough internal dividers to keep valuables away from bulkier items.

And because the pack’s light when empty (560g without bladder) I wasn’t worried about filling it with a day’s worth of food and kit.

The Crux 3-litre bladder is easy to stash in its own compartment and thanks to the removable straw – that doesn’t cause the bladder to leak water when unattached – it’s easy to fit and remove by leaving the straw in place.

At this price point, it’s good to see a quality bladder is included.

CamelBak M.U.L.E. 15l mountain bike backpack
There are reflective accents on the bag.
Simon Bromley

Once the bladder is full, the carrying capacity shrinks quite quickly, especially if the bag has already got tools, snacks and valuables packed in. Luckily the M.U.L.E.’s material is fairly stretchy and, even when it was very full, I never struggled to close pockets or thought it looked like it was about to pop.

Because the securing straps are quite thin, its weight isn’t shared out very well across the bag’s contact points. This is most noticeable on the hip strap that’s especially thin and, as the ground becomes bumpy, the pack can sway around and bounce up and down, which can cause discomfort around the hips if the bag’s jolting around a lot.

CamelBak M.U.L.E. 15l mountain bike backpack
You get separate pockets for valuables, too.
Simon Bromley

The simple to adjust straps mean it’s easy to position the bag in the correct position without much fiddling and any excess lengths of strap store away neatly.

Against my back on prolonged climbs it caused quite a bit of sweatiness. There’s limited space between the mesh backing and the air channel, which makes it tricky for air to circulate. The mesh isn’t very tight, either, which meant the pack compressed onto my back.

On top of that, when the bag was full it bulged out towards my back because it’s fairly flexible. This didn’t help with how sweaty it was.

However, it did shed water well, resisting some pretty hefty downpours. It isn’t supplied with a rain cover, though, so if you’re planning on venturing out in monsoon-like weather, it might be wise to consider additional waterproofing.

CamelBak M.U.L.E. 15l mountain bike backpack
Helmets mount to the outside of the bag, not encroaching on carrying capacity.
Simon Bromley

Helmets are attached by feeding the strap into small hooks, but I found the mounting system not compatible with D-buckle helmets with short straps, ruling out a significant number of full-face lids. I also found that open-face lids with shorter chin straps didn’t mount very well.

Once the helmet was mounted it didn’t bounce out or fall off the bag even over very rough terrain, but the helmet’s straps twisted in the hooks making it quite tricky to remove.

Because the lid is carried externally the bag’s carrying capacity isn’t affected, but with a lid attached it did make accessing the front pocket difficult.

CamelBak M.U.L.E. 15l mountain bike backpack
The helmet’s straps attach to small hooks to keep it in place.
Simon Bromley

It was possible to squeeze in a pair of kneepads to the outer elasticated pocket with a helmet attached but it’s more suited to jackets and other squashable items.

Chin bars from convertible lids are easy to secure in the same elasticated pouch, but don’t expect one to fit if there’s a set of knee pads already stowed.

CamelBak M.U.L.E. 12l backpack bottom line

The M.U.L.E. 12l is still a good pack and holds its own against a stacked field thanks to the great bladder, multiple internal pockets and ease of use.


It’s got a classic design and is light when unladen, and because of that, it’s easy to forgive it for its deceptively small size, limited securing straps and tendency to bounce around over very rough terrain.

Product Specifications


Price GBP £109.99USD $110.00
Weight 780g – With Crux 3 litre bladder
What we tested CamelBak M.U.L.E. 15l
Year 2020
Brand Camelbak


Bag capacity 15l
Bladder capacity 3l