Our reviews

/100 by , posted on .

Alas, the New Balance Leadville v3 ceased production, and the quest continues for a worthy replacement.

As a middle-aged, highly competitive, trail runner with a history of calf strain problems my criteria are:

  • A decent drop (preferably 8mm+)
  • Adequate cushioning for 60km+ runs
  • A trail shoe with sufficient traction and protection for a variety of terrains
  • A lighter weight shoe (preferably <300g) for performance



The New Balance Summit Unknown has been touted as a natural successor to the Leadville, being a high-end trail show from the same manufacturer.

But how does it measure up in practice?

My Testing

This review is based on at least a dozen runs totalling over 200km on hilly, sometimes muddy and sometimes rocky terrain. I have not tested the shoes on runs for more than two hours.

My experience with shoes lacking midsole cushioning is the basis of my decision for the maximum run duration.

However, it is still important to note that the lack of cushioning contributes to the light weight of the shoes.

Comfort, Midsole and Insole

Arguably the most important aspect of any shoe, I consider the Summit Unknown’s comfort fairly average. On the plus side, they were not uncomfortable out of the box.

Also, the fit is reasonable for my medium to slightly wide feet. Some reviewers have noted issue with the tongue dropping/scrunching up.



I have not experienced this although the neoprene-style tongue is one of the least comfortable tongues I have encountered in trail shoes.

Overall, the shoe has a slightly rigid, plastic feel. Additionally, the uppers are not particularly soft or comfortable.

The Summit Unknown boasts a highly desirable 10mm drop. This drop is crucial for a runner susceptible to calf tears and calf strain. The drop reduces the pressure on the calves.

However, I don’t find these shoes particularly comfortable. It's because of the overall modest heel and forefoot height combined with a relatively hard, unforgiving midsole.

In this regard, I would not use them for runs over two hours as the cushioning is insufficient for this purpose.

I have not experienced any movement of the insole in wet conditions. The shoes are performing well in this aspect.


This criterion is a huge plus for the Summit Unknown. The shoes weigh 245g. This is well under the weight of the Leadvilles (293g) and the majority of trail running shoes.


The mighty Leadvilles boasted a Vibram outsole that was hard-wearing and the uppers lasted for a long time. It is a little early to tell if the Summit Uknown will go the distance.

Nevertheless, the outsole does not appear to show noticeable wear after 200km on the trails. However, there are some tell-tale signs of fabric abrasion occurring on the uppers.



These abrasions can be found at a logical location, around the flex-point on the big-toe side of both shoes.


Another huge plus for the Summit Uknown is the good amount of traction from the lugged outsole. This is one area in which the Leadville had a chink in the armour. 



The Leadville did not grip well in muddy and wet conditions. The Summit Unknown perform very well in this regard


The very light weight of these shoes and modest stack height might be expected to yield a highly nimble shoe.

However, my experience is a little disappointing in this regard. It might be due to the hard midsole and plastic-like uppers.

Wearing it feels a little like wearing clogs, albeit light and grippy ones. A little more flex in the midsole might help in this regard.


The Summit Unknown is certainly not an expensive shoe compared to other brands’ top-end models.

However, the true test for value is not only the ticket price but the longevity of the shoe and enjoyment whilst wearing them. In this regard, the Summit Unknown performs reasonably well.

Summing up

Unfortunately, the New Balance Summit Unknown is not, for me, a worthy successor to the New Balance Leadville for longer trail runs. They are a little more minimalist.

Thus, it does not provide the same level of comfort or enjoyment of the trail. However, it is still worthy of consideration for shorter off-road runs given their low weight and superior traction.

The quest continues…

| Level 1 expert Verified
I'm Tim, a 'middle-aged' but competitive trail runner. I typically run between 50kms and 100kms per week depending on forthcoming races. Also, I've competed in countless trail races and ultra-marathons. I'm pleased to still be competitive with the young guns—coming second overall in the New Zealand Trail Running Championships in 2018 and 8th overall in the prestigious Kepler Challenge. I've run the odd marathon and am a keen Orienteer and Rogainer.

/100 by , posted on .

Trail running is where my heart really lies. Those ephemeral moments that last so briefly that you wish you had someone to experience that fleeting moment with you.

I ended up with the New Balance Summit Unknown after some great customer service from New Balance. I was set on using a pair of the Hierro V3 fresh Foam for my races last year but had a bit of a nightmare with them.



I think I may have had a defective pair, or they just didn’t work with my forefoot strike. But I ended up with the sole of my foot bruised and then to add to the issues the sole of the right shoe started coming away from the upper.

Cue the customer service team at New Balance, and after an exchange of emails and images, I was refunded for the shoe, and I ordered the Summit Unknown as a replacement.

Initial impression

Out of the box, the bright orange trainers meant that I wasn’t going to be missed on the trails. Eye-catching and the reinforced toe box is reassuring you that those rogue snags won’t be catching your precious toes easily.


The upper material is lightweight but is not waterproof. This does drain and dry quickly. So, your feet don’t feel like they are swamped when you step in that inevitable puddle.

As many people have mentioned the tongue of these is quite short. But unlike many, I have not experienced any slippage or stones in the shoes. The collar of the shoe is lightly padded and with this shoe being aimed at faster/race runs its intention is evident.



I have run about 120 miles in these shoes on a mixture of trail types along the South Downs Way and the transitions between surfaces have been smooth, even though the shoe is a trail shoe using it along the road to get to or between the trails is comfortable.

This probably comes down to the Revlite midsole of the shoe, which although not of the maximal design provides good cushioning and protection for the feet. This in part is helped by the footplate in the forefoot to help nullify the hazard of stones impacting the sole of the shoe.



The amount of cushioning in the midsole does lead the shoe to feel responsive, and your feet feel in touch with the trail.


The grip on the outsole of the Summit Unknown is provided by 5mm lugs that perform well on the shales and gravel of the South Downs Way. Whilst easily being able to cope with softer sections of the trail when required.

I have found limits to the shoe grip at the more extreme end of the mud spectrum. But there are other shoes out there that excel at that which I would use if I needed to. Over wet rocks, the grip is exceptional and gives you the confidence to push hard without fear of slipping.



This shoe suits me as a forefoot runner, with a need for the shoe to flex in the forefoot. I was surprised at how flexible this shoe was even though it has the incorporated footplate.

Over shale, gravel, and mud, the grip will not let you down and wearing the shoe on the road to the trails is painless due to the flexibility of the shoe. The only limitation of the shoes I have found has been in the extreme mud and at 175lbs.

I would have doubts on how my feet would cope with any ultra-distance events in these. I think though that is my limitation rather than the shoes, as I have worn them on the trails for 22 miles without any issues.

At the moment, these are my go-to trail shoes, and I don’t have any doubt that they will get used until they are gardening shoes. The Summit Unknown will appeal to those looking for a lighter/faster shoe for the trails.

Many will be drawn to the maximal shoes of the moment, but to me, they wrap your feet in a bubble and shut you off from the trail experience. Unwrap your feet and get closer to nature with these Summit Unknown. You might like it.

| Level 2 expert Verified
Hi, I'm Mark and I've been running since 2016. I was a rugby player before and used to run about 20 miles a week at the most. Since then, I entered 3 trail marathons and 4 half trail marathons. I will be running my first road marathon next month with an aim to run a time of 3.10. I also have a trail double marathon, 32-mile ultra and another trail marathon booked for the year.

Updates to New Balance Summit Unknown

  • The Summit Unknown is a reliable New Balance trail running shoe that’s created for the neutral runner. It features a trail-optimized design to bring confidence over a variety of outdoor terrains. The outer tread makes use of a sticky rubber compound to provide grip on dry and wet surfaces.
  • Cushioning is handled by the RevLite foam which is a full-length compound that offers responsive cushioning and shock attenuation. Affixed between the midsole and outsole is a high-density forefoot plate for protection against debris and irregular surfaces.
  • The upper unit features a synthetic mesh to provide a secure and well-protected coverage. It has tiny ventilation holes that allow air into the foot-chamber. Complementing the external mesh is a set of thin overlays and underlays.

Size and fit

The New Balance Summit Unknown makes use of standard measurements to accommodate the preferences of consumers. Lengthwise, it adheres to the regular expectations. The women’s version has these widths: B – Medium and D – Wide. The men’s iteration features the D – Medium and 2E – Wide variants. The semi-curved shape of this shoe’s last mimics the natural curvature of the human foot.


The outsole unit of the New Balance Summit Unknown utilizes the HydroHesion rubber compound. This full-length material is specially designed to provide traction on wet surfaces. Having this layer would potentially increase confidence when tackling slippery trails and paths.

A semi-aggressive lug-pattern allows this shoe to traverse different types of topography easily. Also, the multi-directional configuration of these nodes permits confident uphill climbs and downward excursions.


RevLite is a lightweight material that is advertised as more responsive and sturdier than heavier midsole compounds. It’s been designed to resist early sagging or breakdown.

The Rock Stop® is a layer of dense material that’s placed in the forefoot section. Its purpose is to protect the underfoot from rough surfaces and trail debris. It also attenuates impact shock and diffuses the energy generated by such a force.

A foam insole is placed above the primary midsole unit. It can be replaced or removed entirely.


The façade is mostly made using a synthetic mesh which is a lightweight material that offers breathable coverage. It has a semi-closed construction to improve its durability.

Fantom Fit is an overlay-and-underlay system that’s composed of two materials that have been combined using a no-sew method. The goal of this add-on is to assist in providing a secure yet customizable fit.

Protecting the forefoot section of the New Balance Summit Unknown is the Toe Protect™ compound, which is a thin layer of rubber that acts as a shield against sharp objects on the trail.

The tongue and collar are padded. These two sections hold the foot in place and prevent it from wobbling inside the foot-chamber.

Soft fabric lines the interior of this shoe. It’s crafted to stave off hot spots and skin irritation.

A pull tab is placed on the back portion of the collar. This loop makes it easy to wear and remove the Summit Unknown.


How New Balance Summit Unknown ranks compared to all other shoes
Top 32% trail running shoes
All trail running shoes
Top 37% New Balance running shoes
All New Balance running shoes
Top 34% neutral running shoes
All neutral running shoes


The current trend of New Balance Summit Unknown.
Compare to another shoe:
Jens Jakob Andersen
Jens Jakob Andersen

Jens Jakob is a fan of short distances with a 5K PR at 15:58 minutes. Based on 35 million race results, he's among the fastest 0.2% runners. Jens Jakob previously owned a running store, when he was also a competitive runner. His work is regularly featured in The New York Times, Washington Post, BBC and the likes as well as peer-reviewed journals. Finally, he has been a guest on +30 podcasts on running.