New Balance Fresh Foam X Hierro v9 Review: A Comfort-Focused Road-to-Trail Cruiser

Introduction

The New Balance Fresh Foam X Hierro v9 is a trail running shoe designed to be versatile across a lot of terrains. In the past the Hierro has very much been a road-to-trail model, and that is still true of the v9, but a revamped outsole makes it noticeably more suitable for a wider range of trails.

It costs $155 in the US, a slight rise from previous models, and the prior version sold for around £140 in the UK. It weighs 311g (10.9oz), with a 4mm drop and a 42mm stack height at the heel and 38mm at the forefoot, so this is a big cushioned shoe with a substantial outsole included in that figure.

Who This Shoe Is For

This is an approachable trail shoe for people who mostly run on roads and park paths but want something that can handle a wider range of trails without fuss. Think cushioned road shoe first, with genuine trail capability now bolted on.

If your trail running consists mainly of easy recovery runs, forest trails, canal towpaths, and general hard-packed paths, the Hierro v9 fits that brief very well. It is less suited to fell running or very technical mountain terrain, where its size and weight work against it.

Fit and Sizing Advice

The fit is in line with other New Balance shoes, but consider going half a size up. The tester used a normal New Balance size and found it fine on roads, but on trails, particularly running downhill, the foot pushed into the front of the shoe. The substantial toe bumper adds protection but leaves less room to accommodate the foot.

If you are between sizes, or you know your size in New Balance road shoes, going half a size up gives useful extra room for trail work. That is especially true for longer runs: the longest run in the shoe was around 20K, which was comfortable, but downhills still felt tight at the front.

Upper, Midsole and Comfort

The mesh upper has a nice amount of padding around the tongue and collar, and it very much feels like a road shoe in terms of step-in comfort. Protective overlays, a big toe bumper, and plenty of structure around the heel add the support you need off-road.

The midsole uses dual-density Fresh Foam X with a softer layer on top and a firmer layer underneath. That delivers a soft, cushioned landing while retaining the stability you need on trails. This is not the softest version of Fresh Foam X, and the firmer bottom layer and substantial outsole reduce how plush it feels. You do not get the sinking squishiness of something like the New Balance 1080, but it is a genuinely comfortable and protective shoe, especially at the end of a big training week.

Grip and Outsole Performance

The revamped outsole is the big story of the v9. Past Hierro models were slippery in the woods, with any patch of mud causing trouble. This version has noticeably more bite, with longer lugs that grip well in soft conditions, and it also coped well on icy patches of pavement in cold weather.

The grip is comparable to versatile all-rounder shoes like the Hoka Speedgoat or Merrell Agility Peak 5, which lean toward hard trails but carry enough bite for main forest trails. It would not be the pick for a pure fell run or deep swampy sections, but for short patches of mud among mostly hard-packed trails, it copes without you having to think about it.

Ride Feel and Comfort

On the road and hard-packed paths, the Hierro v9 remains a very comfortable cruiser. Comfort is not quite at the level of some road-first trail shoes that offer almost no grip, but the trade-off is well balanced: plenty of cushioning for relaxed long runs, with real grip underneath when the trail turns.

It is not built for faster running. This is a fairly heavy shoe designed for cruising, relaxed long runs, and potentially trail marathon or longer days, where the cushioning and outsole protection pay off. It is not a shoe you would sprint a race in.

Things to Consider Before Buying

The main considerations are fit and pace. Half a size up is a sensible move for trail use, especially if you are between sizes. And if your focus is speed on trails, look elsewhere, because the weight and big cushioned build are geared toward comfort rather than nimbleness.

It also sits between categories. Compared with the Hoka Challenger, it may give up a little road comfort but carries more bite on trails. Against the Merrell Agility Peak 5, the Hierro offers more comfort for cruising runs, while the Merrell is a slightly more capable and nimble option on genuinely technical trails. Compared with the Salomon lineup, it resembles the more comfort-oriented options rather than the lower-stacked, soft-ground-focused Peregrine.

Buying Advice

If you are a runner who does most of your trail miles as easy runs, wants something that can handle UK winter mud and wet patches, and still wants comfort on better trails and hard surfaces through the summer, the Hierro v9 does that job really well. It grips well, feels comfortable on the foot, and has an active-holiday versatility that also makes it a good option for off-road hiking.

Conclusion

The New Balance Fresh Foam X Hierro v9 successfully bridges the road-to-trail and all-rounder categories. It is not the shoe for fell running or fast racing, but for general forest runs, park paths, mixed road-and-trail days, and hard-packed gravel trails, it is a comfortable, protective, and now genuinely grippy package that suits easy-paced trail running very well.