Specialized Mountain Liner with SWAT review – a bib liner equipped with storage, water, air, tools

Specialized Mountain Liner with SWAT combines comfort with a load of storage options for big trail rides without a bag

Specialized Mountain Liner SWAT bib liner
(Image: © Graham Cottingham)

Bike Perfect Verdict

Loads of storage options and comfortable chamois mean the Specialized Mountain Liner with SWAT is perfect for ditching the backpack and hitting the trails


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    A broad range of pockets for storage

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    Front flap for easy toilet breaks

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    Comfortable chamois


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    Short integration is useless unless worn with compatible Specialized shorts

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    Rear pockets can flap when riding technical terrain

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Unless you're heading out on an epic ride in the backcountry, carrying a backpack when riding is becoming less popular. After all, why get a sweaty back and deal with bouncy loads when you can stash everything you need on your bike and in your clothing? Specialized was one of the first brands to champion this with its SWAT concept, providing trail and enduro riders options to ride with bagless freedom.

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SWAT stands for ‘Storage, Water, Air, Tools’, so it should cover all the bases for getting out and hitting the trails for a few hours. Alongside Specialized’s frames with secret downtube storage and craftily tucked away tools came the Specialized Mountain Liner with SWAT. 

Although Specialized was one of the early pocket adopters, many other brands now have their own alternative storage. But does the Mountain Liner with SWAT still compete with the best MTB liner shorts around? 

Specialized Mountain Liner SWAT bib liner

Specialized Mountain Liner with SWAT is made from Specialized's own VaporRize mesh fabrics (Image credit: Graham Cottingham)

Design and specifications

Specialized has used two light perforated VaporRize mesh fabrics to construct the Mountain Liner with SWAT. The upper bib sections are made from the lighter material which doesn’t have much stretch to it, while the lower sections and legs feature a heavier mesh with a little more give. The shorts have a few nice finishes too – there are some light silicone leg grippers and a side pull fly to make trailside toilet breaks easier.

Specialized has leaned on its Body Geometry using a ‘3D Chamois’ which Specialized says is pre-molded to the shape of your body. If you already use a Specialized saddle the Body Geometry chamois is claimed to have been developed to work perfectly together. Whether you are using a Specialized saddle or not, the chamois has a decent depth and density to offer plenty of support on long rides.

Out back there are three rear pockets which are anchored across the top and halfway down each side. The two side pockets have angled openings and the center pocket is wider and deeper. There's also a zipped valuables pocket mounted on the right-hand pocket for stashing keys or cash. Finally, there are leg pockets positioned low down on each thigh.

Specialized Mountain Liner SWAT bib liner

There are three storage pockets at the rear with a fourth zipped valuables pocket (Image credit: Graham Cottingham)


When you first put the Specialized Mountain Liner on the fit feels a little more restrictive. Unlike other bib-style shorts we have worn, it doesn't feel like there is much stretch in the material, especially across the lower back which pulls a little more on the bib liner’s straps. This might be a little odd at first, but once you are on the bike it all makes sense and is very comfortable.

The pad is much the same – less stretch in the pad sets it apart from other chamois that we have used but there is a decent amount of depth and well-considered padding density of padding, which meant we found them more than comfortable enough to rack up serious mileage without discomfort. While we have had mixed experiences with Specialized’s Body Geometry saddles, the Body Geometry chamois kept us happy on long rides using a range of different saddles. 

Despite the limited amounts of stretch the overall fit is pretty good. We would like to see slightly wider shoulder straps as there is a bit of bunching, although that never led to any discomfort. The legs are on the shorter side to avoid any conflict with knee pads and the grippers keep everything in place while riding. Specialized says the VaporRize material offers ‘superior’ wicking abilities and the shorts do perform well in the heat, although not necessarily any better than other bib liners we have tested.

Specialized Mountain Liner SWAT bib liner chamois

Specialized uses its Body Geometry theory when designing the chamois (Image credit: Graham Cottingham)

A good spread of pockets offers loads of storage potential, though as with any half-anchored pocket system, the pockets do have a tendency to flap a little on rough or steep terrain. This does mean Specialized can add more depth without the need to sacrifice reach-around accessibility or risk interference with the waistband on shorts. We found the pockets to be easy to use as well as secure and the layout of two smaller pockets and one larger central pocket gives plenty of storage flexibility as the central pocket can hold a bottle or be stuffed with a lightweight jacket if needed. The two leg pockets add additional storage for those who ride in the best mountain bike shorts, and we found it perfect for stashing a bunch of bars or gels.

If you look at your clothing as a system it makes sense to add a form of integration between the liner and shorts, but this is only useful if you have the corresponding shorts. Not all Specialized legwear is compatible so despite us regularly riding in Specialized’s Trail Pants the integration is yet to be used. We suspect most riders won’t be dressing head to toe in Specialized either, which leaves the little popper loops redundant. Luckily they aren’t annoying when not in use and if your experience is different, it's nothing a quick snip with some scissors won't fix.


Specialized’s Mountain Liner with SWAT packs in plenty of well-thought-out features that make these bib liners one of the best on the market. Loads of storage options combined with a comfortable pad really extend the possibilities of bagless riding. The deeper half-anchored pockets mean there is a little flapping when riding, but it's not that distracting and – more importantly – we found that nothing had escaped mid-descent.

We find that the Rapha Trail Cargo shorts are a touch more comfortable on really long rides although the Mountain Liner with SWAT offers considerable more storage options, making it one of the best all-rounders that we have used.

Tech Specs: Specialized Mountain Liner with SWAT bib liners

  • Price: $120 / £90
  • Materials: Main: 100% polyester / Other: 88% polyester, 12% elastane
  • Colors: Black
  • Size availability: S to XXL
Graham Cottingham
Senior reviews writer, Bike Perfect

Graham is all about riding bikes off-road. With almost 20 years of riding experience, he has dabbled in downhill, enduro, and gravel racing. Not afraid of a challenge, Graham has embraced bikepacking over the last few years and likes nothing more than strapping some bags to his bike and covering big miles to explore Scotland's wildernesses. When he isn’t shredding the gnar in the Tweed Valley, sleeping in bushes, or tinkering with bikes, he is writing tech reviews for Bike Perfect.

Rides: Cotic SolarisMax, Stooge MK4, 24 Bicycles Le Toy 3, Surly Steamroller

Height: 177cm

Weight: 71kg