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Photo credit: www.montrail.com

Montrail FluidFlex FKT running shoes review


Last updated: 17-Aug-18

By Fiona Outdoors

The Montrail FluidFlex FKT (Fastest Known Time) trainers promise to deliver “the perfect blend of flexibility, breathability, fit and traction”.

Montrail adds: “The FluidFoam midsole build brings ideal cushioning while deep-flex grooves and forefoot TrailShield outsole work together to deliver on guidance and protection. The FKT is for trail runners who want to feel light and go fast.”


  • Gryptonite heel and forefoot rubber traction zones with three-point lug shapes for multi-directional traction.
  • FluidFoam midsole with increased flexibility through deep flex grooves
  • Patented FluidGuide technology for enhanced midfoot stability on uneven surfaces and a smooth ride on the trail
  • Seamless upper construction with a thermoplastic midfoot cage welded against a breathable body mesh for protection and support
  • Ride height: 15mm heel/11mm forefoot (4mm off-set)
  • 4mm lugs
  • Weight: 9.2 oz./264 g (men’s), 7.7oz/219g (women’s)
  • Male and female designs
  • RRP: $110 / £85

Photo credit: Fiona Outdoors.

Pros: What’s good about Montrail Fluid Flex running shoes

The trainers feel nicely lightweight but still with cushioning. In fact, the cushioning was a lot better when out on the trail than I expected it to be on first sight.

There is less thickness of sole than, say, the HOKA One One trainers, but more than I have seen on many other lightweight off-road trainers.

The fit is good for people with mid to wider feet. With my narrow feet, I felt as though there was a bit too much volume in the toe box but this didn’t affect how secure they felt at the heel area. Once out running, I didn’t notice the extra room at the forefoot and I enjoyed having a trainer that doesn’t rub, even during a longer run in the wet and mud, and allowed my feet to spread out and breathe.

The trainers look quite attractive. I know this shouldn’t matter. But while fit and performance are far more important than looks, if the shoes are well designed then I approve.

The laces stayed tightly tied once I laced them up and I didn’t have to stop to re-tie or adjust them. So often, laces lose their tautness after a couple of miles of running.

Photo credit: Fiona Outdoors.

Although the drop is only 4mm the footbed didn’t feel too flat. The trainers somehow manage to combine a natural feel but with foot/arch support. I like this because I need a bit of arch support.

The shoes felt best when running on grass and dry trails and paths. There is a lot of flex in the soles and this means it’s almost like running in bare feet, except, of course, you benefit from the cushioned soles.

Although the sole feels fairly stiff there is flex that is created by a series of three shoe-wide grooves along the front area of the sole of the shoe. These allow the shoe to bend and flex far more than other trainers.

I would suggest that if you are looking for a shoe that feels quite natural but has cushioning this is a good choice.

The shoes are definitely a lightweight choice but they are not too flimsy in their design. They look to be robust in all the right places, and surprisingly supportive.

Cons: What’s not so good about theMontrail Fluid Flex running shoes

To start with, what does “Fastest Known Time” mean? I do wish that brands would not use meaningless jargon when naming shoes.

When I first put on the shoes, I didn’t find the uppers to be as comfortable as I’d hoped. The fabric above my forefoot felt like it might annoy my toes but once I was out running I didn’t feel a thing.

I think it was likely that the wider forefoot area caused the upper fabric to “bag” a little because they were new and a bit stiff and this meant it was touching the top of the foot. I never noticed this again after the first 30 minutes of wear.

Photo credit: Fiona Outdoors.

The trainers work well on dry off-road terrain and on tarmac but they are not very sticky on wet grass and mud. The lugs do not offer much grip and they are tightly spaced so mud and dirt tends to clog them up a bit.I would reserve the running shoes for drier conditions and on terrain that is not too steep.

When running on rough forestry-type trails I could feel the stones under my feet. Many trail shoes are like this but I expected to feel less rough terrain because of the cushioning. It wasn’t too off-putting but it was definitely there.

I think these shoes are best suited for summer conditions and off-road hills and paths so they lack versatility if you want an all-season shoe.

Although the colours looked great when I got the shoes out of the box, when covered in mud they quickly started to look drab. The darker shades of the men’s shoes are better at hiding the muck and dirt that comes with off-road running.

Photo credit: Fiona Outdoors.


For a lightweight, barefoot-style shoe that offers a medium amount of cushioning and support, the Montrail FluidFlex F.K.T. running shoes are a great choice. They are super flexible and nicely lightweight. They are best suited to summer paths, grass and smoother trails. I would not trust these shoes to keep me upright in lots of mud or on steep and wet terrain.

Design 8/10
Features 8/10
Performance 8/10
Value 8/10
Total 8/10


Other shoes you may want to consider:

Saucony Peregrine 6
Salomon S-Lab Sense 5 Ultra
Brooks Cascadia 10
Inov-8 Race Ultra 290

About the writer: Fiona is a keen runner, preferring off-road and hilly to flat and road. She lives in Scotland where the weather is fickle so needs to be prepared for all conditions.

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Product Rating


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“The shoes felt best when running on grass and dry trails and paths. There is a lot of flex in the soles and this means it’s almost like running in bare feet, except, of course, you benefit from the cushioned soles”

Where to buy

Columbia Montrail FluidFlex FKT II trail running shoes View deal
Columbia Montrail FluidFlex FKT II trail running shoes for women View deal
Columbia Montrail FluidFlex FKT II trail running shoes View deal
Columbia Montrail Fluidflex FKT II shoes View deal

Review Montrail FluidFlex FKT running shoes review

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