The growing popularity of wearing trail-running shoes for hiking has pushed the market towards lighter and nimbler designs. Merrell’s latest offering in this category is their hybrid MQM Flex, which aims to combine a hiking shoe, trail runner, and moderate approach shoe into one. We put it to the test backpacking in Utah’s Canyon Country and hiking and running in Washington State, and have come away with mixed feelings. The MQM Flex isn’t a one-quiver mountain shoe as advertised, but it’s perfectly capable for hiking and the occasional trail run. Below we break down the MQM Flex’s comfort, weight, traction, stability, fit, and more. To see how the MQM Flex stacks up, see our article on the best hiking shoes.



Putting on the Merrell MQM Flex, it’s immediately clear this shoe is a completely different animal than their Moab 2 hiker. The padding around the heel is pretty thin and the cushioning underfoot is a far cry from the thick foam you get with their most popular design. On the plus side, the MQM feels a lot like a trail runner: it’s light, very flexible under the forefoot, and its low stack height keeps you close to the trail. There’s also just enough protection to keep foot soreness to a minimum while carrying an overnight load or running. All told, it checks the boxes for ambitious day hikes, short trail runs, and ultralight backpacking. But if comfort is a high priority, you may want to stick to a more cushioned shoe like the Moab or Salomon X Ultra 3.
Merrell MQM (hiking trail)


On paper, the non-waterproof MQM Flex’s 1-pound 3-ounce weight makes it one of the lightest hiking shoes on the market. But on our scale, a men’s size 9 (what Merrell states they use for measuring weight) comes in at 1 pound 7.7 ounces. To be fair, it’s still a light shoe—the Merrell Moab 2 Ventilator is 1 pound 15 ounces—but it’s certainly not as impressive as we thought going in. Stepping up to the Salomon X Ultra 3 gets you a jump in comfort, support, and traction for only 1 ounce more per shoe. And the MQM Flex is heavier than hiking-ready trail runners like the Altra Lone Peak 3.5 (1 pound 4.8 ounces) or Saucony Peregrine 8 (1 pound 4 ounces). So, while the shoe never felt truly heavy on my feet—even while trail running—it’s also not the ultralight model we were hoping for.
Merrell MQM (walking close-up)


Given that the MQM Flex aims at combining attributes from hiking, running, and climbing footwear, we set a high bar for the shoe’s traction. But in practice, I’ve been pretty disappointed with the performance overall. The outsole feels fairly tacky, but it was not a standout on steep slickrock, and I am yet to get to a point where I fully trust it when running on technical and rough trails. The short lugs don’t have the bite of a shoe like the X Ultra 3 or The North Face’s Ultra 110, and the design lacks features we’ve found helpful like substantial lugs around the heel for braking on a descent. It’s certainly acceptable for most hiking and moderate trail-running adventures, but if we were to pinpoint one area where Merrell could greatly improve this shoe, it would be the traction.
Merrell MQM (traction)

Stability and Support

In terms of stability and support, the MQM Flex is more like a burly trail runner than a typical hiking shoe. The heel cup is fairly solid, which helps keep ankle rolls to a minimum, but it doesn’t have the wide footprint or planted feel of a shoe like the Moab. That being said, I had no complaints while hauling a multi-day load of just under 30 pounds or while day hiking. If you’ll be carrying much more weight, however, or just prefer a sturdier shoe, it may be worth stepping up to the mid-height MQM Flex or a burlier low-top design.
Merrell MQM (steep hiking)


We tested the non-waterproof version of the MQM Flex, so it’s not surprisingly a poor performer in the wet. When crossing streams, the mesh upper quickly takes in water, but the upside is that the shoe also dries out quickly in sunny and warm weather. Merrell does offer a Gore-Tex version of the shoe (more on this below), which would likely be the preferred option if you plan to hike in the cooler shoulder seasons or need the added protection.
Merrell MQM (mesh close-up)


The advantage of a non-waterproof shoe with liberal use of mesh is that it’s very comfortable in the heat. I backpacked in mild spring conditions in Canyonlands without issues, and I’ve stayed mostly sweat-free in temperatures reaching the high 70s Fahrenheit since. Interesting, I’ve found the MQM does run a little warmer than the Moab 2 Ventilator—perhaps because it doesn’t use as much open-weave mesh—but it’s still a much better breather than any Gore-Tex model out there for summer adventuring.
Merrell MQM (hiking with Levity)


One area where the MQM Flex is an upgrade from its trail runner competition is durability. Merrell did a great job mixing open mesh along the top of the shoe for ventilation with tightly woven mesh and TPU reinforcements in the lower areas most prone to tearing. TPU film and a small rubber toe cap also combine to provide decent protection around the front of the foot. In about 2 months of heavy use, the uppers are holding up very well. Unfortunately, the tread already is showing signs of wearing down, and the shallow lugs means it will most likely be the first thing to give out on the shoes.
Merrell MQM (side profile)

Sizing and Fit

Merrell is fairly consistent with its sizing—the discontinued Moab FST is a notable exception—and we like the overall fit of the MQM Flex. Like their popular Moab 2 model, the shoe has a generous toe box and is snug enough in the heel to keep things locked in place. I ordered my usual men’s 9 and felt it was very true to size. The length and width was great for hiking and running in the heat, but it didn’t feel sloppy or unstable on uneven terrain. Further, the lacing system does a nice job tightening evenly around the midfoot, and I haven’t had any issues with it loosening throughout the day.
Merrell MQM (tent)

Other Versions of the MQM Flex

We tested the men's non-waterproof, low-top version of the MQM Flex (there's also a women's version with the same design), but the line includes two additional flavors: a Gore-Tex low-top and Gore-Tex mid-height boot. The obvious upside with opting for the waterproof models is keeping your feet dry in the wet, but it adds about 4 ounces to the shoes and makes it less breathable. Regarding the MQM Flex Mid, the only changes from the shoe version are the over-the-ankle height and a set of metal eyelets at the top for getting a secure fit. Listed at 1 pound 11 ounces (as with the shoes, we’d want to verify this number), it’s among the lightest boot options on the market.
Merrell MQM (webbing)

What We Like

  • Light and nimble on your feet for moving quickly on the trail.
  • A fairly versatile shoe that offers enough support and protection for both difficult day hikes and ultralight backpacking.
  • We like the fit, which is spacious around the toes, but you can cinch it down nicely around the midfoot and heel.

What We Don’t

  • Quite a bit heavier than the advertised weight, which makes it less of a standout in the market.
  • Not as comfortable as a dedicated hiking model like the Salomon X Ultra 3.
  • Traction was disappointing. The lugs are too short to bite into the trail and the shoe is not as grippy on rock as we’d hoped.

Merrell MQM (lug depth)

Comparison Table

Shoe Price Type Weight Waterproof Upper
Merrell MQM Flex $110 Hiking/trail-running 1 lb. 7.7 oz. No (available) Mesh / TPU
Salomon X Ultra 3 $120 Hiking shoe 1 lb. 9.8 oz. No (available) Synthetic
Merrell Moab 2 Ventilator $100 Hiking shoe 1 lb. 15 oz. No (available) Leather / mesh
The North Face Ultra 110 GTX $120 Hiking/trail-running 1 lb. 15 oz. Yes (Gore-Tex) Leather / mesh
Altra Lone Peak 3.5 $120 Trail-running shoe 1 lb. 4.8 oz. No Mesh

The Competition

The MQM Flex joins a very packed crowd of lightweight hikers, but its combination of weight and good looks—along with the well-known Merrell name—should make it a popular choice. Our favorite hiking shoe for 2018 is Salomon’s X Ultra 3. Where the Merrell has the upper hand over the Salomon is weight by a little over 2 ounces. It’s also better for running with its more flexible construction and lower ankle height. But in all other respects, the X Ultra 3 is simply better. It has far superior traction over rock, dirt, and mud, and is more comfortable and cushioned underfoot for long hikes and backpacking trips. Unless you want a hiking shoe you can run in or you prefer the Merrell’s wider toe box, the X Ultra 3 is the shoe we’d recommend (for more information, see our in-depth X Ultra 3 review).
Merrell MQM (hiking view)

The MQM Flex’s lightweight hybrid design puts it in the crosshairs of one of the top trail-running shoes: Altra’s Lone Peak 3.5. This shoe has developed a strong following among thru-hikers with its thick cushioning, wide toe box, and solid traction. Altra even includes nice touches for long-distance hikers like attachment points for a pair of gaiters. Compared with the MQM Flex, the Merrell has the upper hand in durability, but we give the advantage to the Lone Peak because it’s more comfortable, weighs about 3 ounces less, and grips better on soft ground.

A final alternative is Merrell’s own Moab 2. As I’ve touched on in the sections above, the Moab follows more of a traditional hiking shoe model with greater protection and cushioning along with a very stable platform. This is a winning formula that has made the Moab one of the most popular shoes on the market for years. But the Moab’s are pretty heavy at nearly 2 pounds for the non-waterproof version, and they’re too clunky to use for any sort of running. If you want a lighter weight Merrell shoe for moving fast on the trail, the new MQM Flex is the better choice. But for most hikers and backpackers, the Moab 2 remains the superior Merrell product.

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