Breaking Down Merrell’s AllOut Technology

flashMerrell has long been known for its barefoot-inspired trail running shoes. This year, it’s taking new strides and expanded its lineup by creating the AllOut series, a collection of neutral cushioned shoes that offer a touch more support than zero-drop options.

With the AllOut line, Merrell introduces key new technologies to set the collection apart from its barefoot brethren.

  • 6-mm drop: Rather than having the feet and toes sit even in a line as they do in a barefoot-inspired shoe, the AllOut series instead features a slightly elevated heel (though 6 mm is still half of traditional running shoes’ 12 mm). Thus, this gives you a great middle ground between traditional running shoes and more minimal offerings. If you’re looking to ease into the barefoot-inspired running world or need just a little bit more cush and support on easy days, a 6-mm drop shoe is a good sweet spot.
  • M Select Grip: Merrell uses its proprietary gripping technology on the outsole rather than a Vibram design that is found on other styles, such as the Bare Access. The sticky lugs of the M Select Grip keep rocks and dirt from clinging to the outsole as you run. They push debris out to keep you from falling victim to any ugly trail rocks or roots. Plus, the lugs are angled, which helps them to work on various wet or dry terrains. 
  • Unifly Midsole: Softness where you want  it, firmness where you need it: That’s the sermon the UniFly midsole preaches. A soft, resilient EVA foam—30 percent lighter than Merrell’s barefoot line—runs the length of the shoe. However, firmer foam pods are strategically placed in the heel and forefoot.  The marriage of these two culminate to give you soft landings but firm takeoffs, the best of both worlds.

Merrell has three running shoes in the AllOut collection: the Rush, Fuse and Flash.

The AllOut Rush, due in summer 2014, is the true trail runner of the collection. It’s beefier than the Fuse and Flash but still doesn’t tip the scales. While it maintains a 6-mm drop, it does so with a bit of added cushion compared to the Fuse or Flash. The heel sits at 16 mm, and the forefoot sits at 10 mm. The outsole lugs are spaced further apart to really dig deep into the trails and give you an aggressive advantage.


The AllOut Fuse walks the line between road and trail and sits right between the Rush and the Flash. Its heel height is 12 mm with a forefoot height of 6 mm. The lugs are smaller and placed closer together so you still get plenty of traction but in a more versatile shoe.


Finally, the AllOut Flash is the true road style of the collection. Its outsole configuration is quite different than that of the Fuse’s or the Rush’s. Rather than having lugs riddle the length of it, it instead features rubber in high-impact areas to cut down on wear and tear. It also has the least amount of cushioning of the three—14 mm of cushion in the heel and 8 mm in the forefoot.


All three styles are machine washable and feature Merrell’s anti-odor technology, M Select Fresh. If you’re looking for a neutral cushioned shoe that gives you an unencumbered ride and superior traction, the AllOut series just might be the ticket.

One Comment on “Breaking Down Merrell’s AllOut Technology

  1. Thanks for this post, I was having a really hard time understanding the differences when shopping online! This is a great resource.

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