For their outsole, New Balance used a full-length HydroHesion rubber compound, that is highly abrasion resistant and durable. It features an aggressive lug pattern composed of 4mm lugs with multi-directional nodes, which are perfect for dirt/muddy trails and wet, rocky surfaces. They come especially handy when going up or downhill, as they ensure the wearer has a firm grip on the ground and eliminate the risk of slipping and falling. Additionally, they also provide cushioned footfalls for a comfortable running experience. As the name HydroHesion suggests, this trail running sneaker performs best on wet, uneven terrain, specifically wet rocks, making crossing creeks and rivers a piece of cake. The outsole is also very flexible, with its strategically placed cutouts and grooves, that follow the feet’s natural bending and flexing, enabling an effortless and natural ride. While the more prominent lug pattern on these running shoes would make one think, that they would feel awkward on roads and flat surfaces, that is not the case with the New Balance Summit Unknown. The tread pattern on these trail running shoes feels quite comfortable and grippy on roads as well, which is perfect when you have to cross a road to get to the trail, as they will make a great transition. For protection against sharp rocks and debris, New Balance incorporated RockStop, a high-density plate made of dense material, that is placed between the outsole and midsole and is located in the forefoot region. This plate helps keep the wearer safe while running through creeks with sharp rocks or rock climbing, as well as keeps debris from sticking to the sole and causing discomfort. It also helps absorb the shock of impact. The only area where the New Balance Summit Unknown did not perform perfectly, was on deep mud-covered trails, according to reviewers. However, the general consensus was, that these trail running shoes are an all-around great pair of running shoes for rough terrain.

The midsole unit of the New Balance Summit Unknown is made of an EVA foam called RevLite, which many of New Balance’s shoes have, and it is considerably lighter than many other trail running shoes while retaining responsiveness and cushioning for the ultimate running experience. It is also quite durable and will keep its structural integrity intact even after some heavy mileage on the trails. It is great for both fast intervals and long distance or marathon running, as the shoes are lightweight enough to keep the wearer energized and fast throughout use without sacrificing stability. Thanks to the addition of the high-density forefoot plate, the forefoot region of the sneakers has excellent shock absorption, which transforms into energy that the wearer can use to propel themselves into their next step with ease. For additional cushioning, New Balance included a fully removable foam insole, making these trail running shoes orthotic-friendly. However, it should be noted, that the shoes can feel a little narrow, so sizing up at least half a size to accommodate custom orthotics is recommended. That said, the New Balance Summit Unknown is an excellent trail running shoe, that will keep the wearer protected and in tune with the ground beneath them, for a more secure and confident ride through the unknown.

For their upper, New Balance wanted to create something, that fits like a glove but also provides adequate support and protection for the wearer when on the trail. This is where the Fantom Fit upper construction comes into play. This system of breathable, no-sew synthetic mesh consists of two parts: an overlay and an underlay. This ensures that the feet stay protected from the elements and debris while being able to breathe at the same time. It hugs the feet almost like a sock and is quite stretchy, while the standard lace-up closure ensures a customizable fit, that keeps the feet locked into their proper position without restricting them. The toe box comes with a layer of protection in the form of New Balance’s Toe Protect, a thin layer of rubber, that shields the wearer from stubbing their toes on sharp rocks. This same layer of rubber shield is applied to the heel counter as well, providing additional support and stability for the wearer. The Summit Unknown comes with a padded tongue and collar, which help lock the feet down and prevent them from sliding inside the foot chamber, as well as create a comfortable, blister-free fit with or without socks. The heel comes with a handy pull-tab, that makes putting these shoes on a lot easier and fuss-free, which is especially helpful when you need to get out and running in a hurry. For enhanced breathability and comfort, New Balance included a soft fabric lining inside the sneakers, which also protects against hot spots and irritation while running. Although this trail running shoe is not waterproof, it does drain water very well and dries out rather quickly, making them perfect for running in rain or mud covered trails, and crossing creeks and rivers was never easier. That said, a common problem, that reviewers came across, was, that the foam insole would bunch up in the forefoot area when soaked, creating an awkward feel. However, this was a rather minor issue compared with the tongue. Namely, the tongue on the Summit Unknown would slide off or bunch up on the top of the feet, creating an uncomfortable pressure point quite early in the run. Other than that, the Summit Unknown is regarded as one of the best all-around trail running shoes and quickly became a crowd favorite.

While the Fantom Fit no-sew mesh upper’s underlay keeps the feet protected against debris and rocks, the mesh overlay ensures, that they are well-ventilated throughout use. For additional breathability, a soft fabric lining has been included, which helps protect the feet against hot spots and irritation, while wicking away moisture effectively, for a healthy and comfortable in-shoe environment. The Summit Unknown also drains well and dries out quickly, making these sneakers ideal for running in wet conditions or crossing rivers and creeks while on the trail.

While trail running shoes can feel too clunky and rigid at times, due to their padding and layers of protection, the Summit Unknown found a way around it, where it still protects against the elements of the trail but keeps the wearer light on their feet and comfortable. This is achieved with its lightweight but supportive RevLite midsole and Fantom Fit upper construction. The midsole offers a responsive cushioning and excellent shock absorption, thanks to its RockStop plate, and will keep its form for a long time. The upper’s no-sew mesh construction provides a breathable, yet supportive fit to the wearer, that moves together with the feet for an unobstructed ride. The padded tongue is attached to the sides of the sneakers, creating a bootie-like fit, which helps keep debris out of the foot chamber and the feet locked into position irritation-free. The collar also comes with a light padding, keeping the ankles comfortably supported. Additionally, these sneakers drain water very effectively and dry out fast, so you do not have to worry about your feet being uncomfortable due to moisture buildup. The only issues reviewers encountered, were with the insole and tongue bunching up and creating some discomfort. Luckily, the insoles are removable to accommodate custom orthotics, while the issue with the tongue can be fixed by pulling it up and lacing the sneaker securely, to avoid slippage.

The Summit Unknown fits narrower in the heel and midfoot area with a roomy toe box, which is intentional. The narrow heel and midfoot help keep the feet securely locked down to avoid any injuries caused by the feet sliding inside the shoes, while the roomy toe box allows for a natural toe splay. This trail running shoe is available in both standard and wide widths, making it suitable for people with wider feet as well. However, if you are planning on using your own custom orthotics with this shoe, sizing up is recommended a tight fit.

Even though the midfoot-forefoot portion of the Summit Unknown features the RockStop plate, it is still quite the flexible shoe, especially in the toe area. This is great news for those who like fast-paced running, and the faster you go, the less effort you need to put into your every step, which saves you energy and delivers a fatigue-free ride, even on rough terrain. Running uphill has also never been easier, as the sole grips to the ground firmly and rolls with the motion of your feet for a very natural ride.

The Summit Unknown has great responsiveness, thanks to its RevLite midsole unit, which is a firm but cushioning EVA foam compound. This midsole unit will keep its shape intact for a long time and provides a supportive and shock absorbing foundation for the runner, with excellent ground feel and energy return, delivering springy and bouncy steps for the wearer throughout use. The RevLite midsole translates well into road running as well, making the transitions from road to trail running smooth and effortless, as the wearer can be sure in their steps on both flat and rough surfaces.

Since it is a neutral trail running shoe, the Summit Unknown offers moderate support, when it comes to arch support, and is best suited for people with normal to high arches. However, the insole is removable to accommodate custom orthotics for those who need a little more support in that area. When it comes to the upper, the no-sew synthetic mesh Fantom Fit hugs the feet securely, while still allowing them to move and bend naturally and freely. The lugs on the outsole also provide a secure footing no matter the terrain. Additionally, the heel counter features the same thin protective rubber as the toe box, however, in this case, it serves as additional support for the heel and ankles.

This trail running shoe from New Balance weighs in at about 18 ounces, putting this shoe in the lightweight category, which is uncharacteristic for trail running shoes. This light weight is mostly attributed to the incredibly light RevLite midsole compound, which is much lighter than other midsole compounds found on most trail running shoes. This midsole compound will keep its shape for a long time while delivering cushioned and springy steps with excellent responsiveness. Additionally, the upper’s no-sew mesh construction is quite lightweight, even with the rubber protection layers on the toe box and heel counter. These sneakers will not weigh you down, even when they are covered in mud, and will keep you light on your feet for an energized and springy run.

There are many trail running shoes on the market, however, none are quite like the Summit Unknown from New Balance. This innovative design packs all the protection you will need on the trail, while keeping the weight to a minimum, allowing for a springy and energized ride. Featuring a grippy and sturdy rubber outsole and a super lightweight and responsible RevLite midsole compound, with a RockStop plate for a layer of protection against sharp rocks and other debris, this trail sneaker will keep you firmly on your feet without weighing you down. Coupled with the no-sew Fantom Fit mesh upper, that also features protective rubber layers on the toe box and heel counter, this running shoe can tackle any trail and creek it comes across. While the tongue and insole were somewhat problematic, they do not take away from the greatness of this trail shoe, when it comes to performance and durability. To top it off, they are very budget-friendly, making it hard to pass these up.