Midsole width - heel review

We recommend the Merrell Vapour Glove 6 if you:

• Toebox width at the big toe.
• Require a certain degree of protection in your minimalist trainers.
• Are in search of a durable zero-drop, barefoot shoe suitable not just for running, but also for cross-training and hiking.

The Vapour Glove 6 might not be the right choice if you're after a zero-drop experience but still want some cushioning underfoot.

This shoe puts significant demands on your foot muscles and bones, and it's essential to be fully prepared for the barefoot experience. If you're new to this style, we suggest starting with something like the Merrell Vapor Glove new method, Difference in stiffness in cold.

Durability is another aspect to consider. The Vapour Glove 6's outsole tends to wear out quickly. In comparison, the Both sides full performs better in our lab, despite its softer rubber. However, in the barefoot world, outsole durability is often a trade-off. If your primary concern is just having a zero-drop shoe, the Merrell Vapor Glove Maintains grip, even on wet surfaces.

We mentioned that this shoe has no midsole, and that's exactly the case. The heel stack in this shoe amounts to just the outsole and insole combined, at a minimal 7.6 mm.

What does this mean? For barefoot enthusiasts, it's great news. However, if you're used to running in cushioned shoes, you'll need to take it step by step with the Vapour Glove 6. There's hardly anything between your feet and the pavement!

We took our trusty calipers to the forefoot and found exactly what we were hoping for in a true barefoot shoe—a consistent 7.6-mm stack height. Fantastic!

Naturally, subtracting the forefoot from the heel measurement gives us a true, unequivocal 0.0 mm drop.

While this might seem obvious for a zero-drop shoe, manufacturing tolerances often lead some shoes to stray slightly from the perfection achieved by the Vapour Glove 6. Of course, the lack of a midsole certainly contributes to this precision...

The outsole of the Vapour Glove is made by Vibram. That equals fantastic grip.

However, this time Vibram provided the EcoStep Recycle rubber. It's softer (75.6 HC) than other compounds from the Italian company, like Megagrip, and also softer than the average shoe's rubber.

The EVA-based insole measured 3.8 mm, and it's the only cushioning you'll feel in this shoe.

We always begin by testing every shoe on our feet before diving into measurements.

Right away, the Vapour Glove 6 felt comfy yet a bit snugger than most barefoot options on the market—a sensation we later confirmed with a precise measurement of 93.3 mm across the widest part of the 1:1 gel mould we created.

Our second measurement, focused on the big toe area, revealed that Merrell has thoughtfully honoured the natural shape of the foot with 77.5 mm.

This is excellent news for toe splay enthusiasts and checks all the boxes for a barefoot running shoe.

Great news for those who value both lateral and vertical toe movement. Measuring 31.0 mm, the toebox offers ample space, delivering a freedom-focused fit.

Another huge advantage of not having a midsole and being extremely connected to the ground is the stability it offers. And the huge sidewalls also play a big role acting as a support element.

The Vapour Glove 6 is as stable as your feet, and it feels amazing while running. Oh, and these things just love taking corners at full speed... just saying.

The torsional rigidity test is crucial for barefoot and minimalist enthusiasts, and we're happy to confirm that the Vapour Glove 6 is extremely flexible, scoring a 1/5 for us.

Merrell Vapor Glove new method!

The story is the same with the heel counter. There are no added stability elements, no intrusive heel counters, absolutely nothing.

Now, let's look into the midsole dimensions. In the forefoot, we measured a maximum of 104.6 mm, which is actually high for this type of shoe!

The heel measured 77.0 mm, in line with our expectations. These foot-shaped shoes always tend to get really narrow in this area, and that's exactly as it should be to fit like a glove.

Doing this test was pretty cool. Usually, we have to apply some serious force, but this time we had to be super careful to push just lightly enough to avoid going past the 90-degree point.

Midsole width - heel!

Following a 20-minute freeze, just like we did for the midsole softness test, we repeated the flexibility test. This time, the result was nearly identical at 2.5N.

With just a 12.7% increase, you won't notice any difference, even in cold temperatures.

Weighing just 5.6 oz (159g), the Vapour Glove 6 is among the lightest shoes we've tested in the lab. However, don't be fooled—its lightness is mainly due to the absence of a midsole.

In fact, the upper is quite heavy because of all the padding it includes.

The Merrell Vapour Glove 6 stands out, but its upper is similar to what you'd find in most running shoes. We were curious about its breathability since the upper looks highly breathable.

Our first, most visually striking test involved using a smoke-pumping machine to assess breathability. In the lab, we rated it a solid 3/5, which works for us since this shoe is intended for year-round use by most people.

We found less airflow than expected in the toebox, but pleasantly surprised by the nice ventilation in the midfoot area. This is great for everyday use.

Then, we took a closer look under the microscope to understand why the toebox wasn't as breathable.

The answer is straightforward—there's a dual-layer setup, with fabric below the mesh, which restricts full airflow.

However, this design greatly enhances comfort, and we think it's a fair trade-off, especially since this shoe is designed for all-day wear.

We spent a long time testing the shoe and handling the upper. As a result of it, we realised it's really soft and comfortable, which made us a bit concerned about its durability.

After conducting our Dremel test, we were relieved. The shoe scored an average 2/5, which is quite good for such a comfy upper.

The heel area showed the same performance as the toebox, so we gave it another 2/5.

We don't think this is a major concern, except for those who often wear holes in the Achilles area.

The outsole of the Vapour Glove is made by Vibram. That equals fantastic grip.

However, this time Vibram provided the EcoStep Recycle rubber. It's softer (75.6 HC) than other compounds from the Italian company, like Megagrip, and also softer than the average shoe's rubber.

Merrell Vapor Glove.

Unfortunately, those doubts were confirmed when we found a 1.5-mm indentation in the outsole after our Dremel test in the lab, suggesting it might wear down faster than anticipated.

Fortunately, Merrell requested a thick outsole from Vibram, and we found they delivered with a 3.9-mm one, which is beneficial considering the results of our previous tests.

At just £90, we weren't expecting any reflective elements at all, and that's what we got.

This is pretty wild—the tongue is actually thicker than the shoe's stack height!

We're talking 8.2 mm thick here. It looks like Merrell really wanted to amp up the comfort in the upper as much as they could.

The tongue is semi-gusseted, which is a nice bonus for those light trail adventures filled with small rocks and debris. In our opinion, Merrell deserves a bonus point for including this feature in a £90 shoe.

There's no heel tab on the Vapour Glove, but we don't think it would fit with the design anyway, so it's all good!

The insole is glued in and can't be removed. Additionally, the shoe's shape and its minimalist design don't make it suitable for third-party insoles.