Barefoot Shoes

Shamma Sandals Numa Warriors and Numa Chargers (Plus a TrailStar Maximus LE update!)


The always-innovative folks at Shamma Sandals demonstrate their tireless dedication to thoughtful design with an all-new sandal that is perfect for summer! Read further for my thoughts on the Shamma Sandals Numa Line! Today, we will review the Numa Chargers with a goat leather footbed the and Numa Warriors with the Ultragrip footbed.

From the Manufacturer:

Chargers: The Shamma Sandals Numa Chargers are designed to provide the ultimate barefoot experience on the toughest city streets. They are simple to use, easy to put on, and seamlessly connect you to a sole perfectly tuned for urban life. You’ll never view concrete and asphalt the same way again.

Warriors: Numa Warriors get you the closest you can to feeling barefoot in a sandal. A lightweight sandal that moves effortlessly with your foot, the Numa Warriors create the ultimate barefoot experience. You’ll be at home on your favorite local trail or the most epic national park. Numa Warriors are barefoot bliss.

Vibram Morflex returns for the Numa Chargers. An excellent All-Around sole!


The Shamma Sandals Numa Chargers, like a beloved fixed-gear bike or a trusty 35mm prime lens (though 40mm is actually my favorite), may not deliver top performance in every situation, but they shine with versatility, simplicity, and overall enjoyment.

These Chargers feature the same 6mm Vibram Morflex pyramid sole found in other Shamma sandals. Morflex, a microcellular material, conforms to your feet over time, offering flexibility without floppiness. It’s incredibly lightweight and has a slight bounce-back effect from impact.

Unlike denser rubber soles that create a slapping effect, the Morflex sole flexes gently upon landing, providing a smoother experience. This pliable yet sturdy property makes Morflex an excellent choice for road running and general use. Although the treadless design limits performance in extreme conditions, the sole’s softness allows it to grip through foot pressure, adapting well to various surfaces.

The Morflex sole is a true jack-of-all-trades, handling most situations with impressive versatility. The pyramid version offers slightly better grip and a denser composition than the older, flatter Morflex sole, though the pyramid dimples flatten out quickly.

Morflex is excellent for road running, trails, and everyday enjoyment. The lightweight sole, combined with an overall lighter design than the more upscale Chargers, provides similar capabilities and comfort.

During long hikes, I often forget I’m even wearing them!

The Morflex sole compresses to the shape of your foot over time, particularly in the heel and ball areas. Even after hundreds of miles, I’ve yet to wear a hole through the Morflex sole. While the straps may eventually fail, the sole endures. For roads, cities, and light trails, Morflex is a fantastic compound that I highly recommend for running and exploring.

The Morflex compound, a blend of rubber and EVA, is renowned for its lightweight properties and a firm yet cushioned feel underfoot. It also boasts a quick break-in time. While not as thin as the Warriors, Chargers offer a preferable option for those seeking a very thin sole with a touch of cushioning.

Morflex is lighter and less dense than Vibram Newflex, Cherry, Zegama, and Gumlite. However, it is not delicate. I have enjoyed hundreds of road miles with every single one of my Morflex sandals over the last 12 years and none of them have failed on me. The lack of treads and nubs will be felt in wet and slippery conditions, but Morflex is excellent for roads, dry conditions, everyday use, and light hiking.

Other options for soles include:
Numa Warriors – 5mm Newflex sole
Numa Maximus – 8mm Newflex sole
Numa Alpha – 5mm Newflex and 6mm Vibram® Morflex

My picks would be the Warriors for more aggressive activities or the Chargers, both are the lightest options with maximum flexibility and dexterity.

The 5mm Vibram Newflex Sole in the Numa Warriors

The Vibram Newflex sole used in the Warriors is 5mm thick, compared to the 6mm thickness of the Vibram Morflex sole used in the Chargers. While this 1mm difference may seem minor on paper, the rubber compound, tread pattern, and flexibility of the Warriors’ sole are significantly different. The Newflex rubber is designed for tougher terrain and more challenging weather conditions, offering excellent flexibility. Despite being thinner, it is denser than Morflex and features an aggressive lug pattern. This pattern makes the ends of the lugs 5mm thick, but in the areas where the cuts are, the thickness reduces to about 2mm. This design provides a very flexible and lightweight sandal with superior traction.

For those looking for more protection, the Maximus gives you the same Newflex sole as the Warriors, but with 30% more material and the Alpha combines Newflex with Morflex for comfort and treads, but I personally prefer the thinner sandals, but it is good to know your own preferences and to have options that will cater to your needs.

Aesthetics and Materials

With the Numa line, Shamma Sandals has introduced a new lacing system that is their most comfortable and smooth system yet!

Prior sandals that have experimented with an elastic strap usually incorporated the strap in the heel section, like how you may pull on the back of a slipper or shoe to wear them. The issue that I have experienced with elastic heel straps is that they tend to be a bit too loose and the heel, and therefore the entire foot, ends up feeling sloppy as a result. This is especially true when going uphill.

Shamma’s interpretation of an elastic strap comes from acknowledging that the convenience and comfort of an elastic must be utilized in a way that does not interfere with the use of the sandal. Instead of an elastic heel, they opted for a single elastic strap along the top of the sandal that flexes and adjusts on its own using a custom floating buckle. You can manually slide this buckle to a desired comfortable location, but it adjusts on its own to where it needs to go. Having this single elastic band means that tension is distributed evenly and against itself, which keeps the stretching within a comfortable range that allows for more activity than an elastic strap should really be used for.

The Numa lacing system is a hands-free, slip-on lacing system that effortlessly adapts to your foot’s movement, providing unparalleled comfort and ease of use.

Shamma uses a custom ¾” elastic forefoot section which stretches around the front of the foot along the arch and middle of the foot, ensuring a single, seamless connection between your foot and the sandal. This innovative design includes a self-adjusting toe plug buckle, with the aim of offering the comfort of flip-flops without compromising on convenience. The system also incorporates flexible heel posts to keep the heel strap optimally positioned, and the laces are crafted from Ultrasuede for exceptional comfort.

The strap comes with a lot of material for a custom fit on any foot.
Strap after trimming off excess materials.

Years ago, a different shoe company told me that they cannot make shoes that fit all humans and I think Shamma Sandals took this as a bit of a challenge. The elastic loop in the Numa threads through a side buckle and features plenty of excess trap material to fit any foot. No matter how svelte or beefy yout foot may be, you will find a perfect fit. Simply adjust to your foot and cut of the extra strap material. As a con, this is an extra step, but a worthwhile one to achieve maximum comfort.

The rear of the sandal uses a Velcro and Ultrasuede combination that is similar to other models. This Ultrasuede is very light, durable, and comfortable.

While this is more of a leisure sandal, you can certainly run with them! They are not quite as secure as other Shamma Sandals models that are pure Ultrasuede and Velcro, but for a cruise (Cruzer! get it!), they work fine and with good running form, they are great road running sandals.

Goat leather upper vs ultragrip upper

According to Shamma Sandals: For use in harsh conditions, pair them with the UltraGrip footbed. Alternatively, for added comfort in drier environments, opt for the Goatskin Leather. I agree with this assessment. However, the leather may get wet, but it does dry out relatively quickly and its color may darken, but I have never had a single Shamma Sandal leather upper completely dry out and crack on me. Under normal circumstances, I would recommend a leather oil, but it has never been an issue for me.

Vibram Newflex and Ultragrip footbed, the ultimate combo for summer

Equipped with the ultragrip footbed, crafted from waterproof Toughtek® for superior traction and drainage over the leather footbed. The ultragrip footbed has small channels for water to flow throughout and it is waterproof for fun at the beach or kayaking. However, I would not discount the leather uppers for any water punishment, they are not necessary made for water, but they are very durable and I have never had an issue with them in water, so it is more of a matter of choice.

The Ultragrip footbed is a great choice if you want to enjoy more types of activities in all weather. The feeling of wearing the Warriors with the Ultragrip footbed is like being invincible. You will happily climb every rock and tree and splash in every river you come across.

Future Improvements

There is an Ultrasuede connector near the toe plug that is a slight shade of blue. I would like for this to either 1) be truly black like the other Ultrasuede materials or, better yet, 2) have different color options to add a splash of color to this lifestyle sandal.

This is not a Numa-specific thing, but I would also like to see more colors of leather. We have black and tobacco brown for years, but I think that some sort of slate and other colors would really give the sandals a bit of pop.

Update: I saw that they have new ultraseude colors with their Elite Models on the Shamma Sandals website that are beautiful! Hopefully, they start adding colors to other models!


Shamma Sandals has created what I believe is the perfect lifestyle sandal!

The Numa Lace System and Chargers Sole is a great combination for this summer! They are very comfortable and are perhaps the first successful application of an elastic lace system in a sandal!

For more exciting adventures, go for the Warriors with the Newflex sole and waterproof Ultragrip uppers!

Shamma Sandals has their Fourth of July Sale going on. Enjoy some savings from Shamma Sandals. All of their sandals are made in the USA!

Shamma Sandals Trailstars Maximus LE Update:

Since my last review of the Trailstar Maximus LE, Shamma Sandals has updated their Trailstars Lacing System!

Old review Here:

You will see the new version (left) and old version (right) in the remainder of this review.

New version on the left, old version on the right: Note the new top strap design and how beautifully the leather ages after a year of constant wear

Shamma Sandals continues to streamline and polish their designs, so we actually get annual updates to their sandal models! No other sandal maker does this and it really speaks to their obsession with improvements and customer feedback.

Strap trimmed on the left. Untrimmed on the right: Plenty of extra material to fit any foot

The new strap now features a single loop of Ultrasuede on the top of the foot with an adjustable buckle and ditches the top Velcro strap.

This cuts down on weight, creates a smoother aesthetic, streamlines the look, and adds to the durability of the sandal long term. I have always felt that while this top section did have the ability to adjust using Velcro, once you dial in your fit, you never really need to undo the Velcro. Clearly, Shamma Sandals had the same idea. This loop threads through a side buckle and features plenty of excess trap material to fit any foot and you simply adjust to your best comfort and cut of the extra strap material. This is similar to the Numa Sandal in this regard.

5mm Newflex Sole

The rear heel strap adjustments are still locked into place using Ultrasuede and Velcro, much like the older versions.

My version still uses the Newflex (Maximus) sole, but it does feel like this formula of Vibram Newflex is a little stickier than the old version. It is a little denser to the touch.

Overall, this update makes my favorite sandal even better!

By Jarvis

Minimalist ultra-marathon runner with flat dinosaur feet.

50K Ultra-Marathon Runner

Associate Dean

I hold a PhD in Political Science.
You can follow my photography adventures at and Instagram at

3 replies on “Shamma Sandals Numa Warriors and Numa Chargers (Plus a TrailStar Maximus LE update!)”

I 100% agree with you about the Shamma barefoot sandals. I have a low volume much sleeker foot and still these sandals have an incredible fit. Great durability as well

I’m actually debating between these two sandals (Leather Numa Chargers and Leather Trailstar Maximus), which one is more comfortable? Straps as well, but especially the footbed, for standing and moving on tile.

My use case is no running, only walking around. I have Curious Reds (great sandal, little too much stack height) and Xero Jessie (too floppy, with no squish) and a crapload of Wildlings that I love.

Hi H!
That is a very tough choice! The Chargers will have the Morflex Sole, while the Trailstar Maximus uses Newflex. There is a Numa Warriors version that uses Newflex that I also reviewed here.

It might come down to how much you like having a toepost. The Trailstar series does not use a toepost, but rather a toe loop that is very comfortable. If you are used to a toepost, then it would not matter.

They also have a different look. The Trailstars are more aggressive with more straps that zigzag over the top of the foot, while the Numa looks like a more traditional huarache (and most people will just say “flip flips”, but that is not the case).

Between the two, I still prefer the Trailstars Maximus because they can do anything and are very comfortable, while Numas are very comfortable, but do slightly less. I also prefer the extra control I have with the toeloop in the trailstars. Because the straps zig zag over the foot the way that they do in the Trailstars, the tension is distributed better than in a standard three point sandal, like the Numa. The Numa’s elastic straps are very nice to have, but I think the many ultra suede straps of the Trailstars makes them more comfortable in the same situations and activities, while being better suited for more activities. I hope this helps!

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