Keen Revel IV Polar Mid review

by Solereview editors

The Keen Revel IV EXP Polar Mid boot in the snow.

Keens’s marketing pitch: All warmth and traction, no bulk.

Upper: High-denier Nylon with Ripstop mesh and fused overlays. 200-gram Keen Warm insulation, Keen Dry waterproof membrane.

Midsole: Single-density EVA foam, PU insole with thermal footbed.

Outsole: Keen Polar traction rubber.

Weight: 601 gms/ 1 lb 3 Oz for a half pair of Men's US 9/UK 8/EUR 42.5/CM 27

Widths available: D - regular (reviewed)

Previous model: Keen Revel III

There’s nothing wrong with the Keen Revel IV per se, but there are better boots available for the same price. The Revel IV's stiff upper needs a break-in period, and the Polar Traction outsole is underwhelming.
Stable and temperature-resistant midsole, reflective trims, true-to-size fit
Overpriced, Polar Traction outsole is more bark than bite, low position of tongue gusset limits waterproofing, average insulation, low midfoot ground clearance makes using a gaiter difficult, stiff interiors require a break-in period

The invoice for the Keen Revel IV.

The Keen Revel IV EXP Polar was purchased at full retail price for our review. The amount is in Canadian Dollars.


The box of a Keen shoe.

Nearly two decades ago, Keen’s first mainstream product was the Newport sandal.

The origin of most successful shoe brands can often be traced to a single product. For Keen, it happened to be the Newport sandal.

Over 15 years ago, Keen suddenly arrived into the mainstream on the back of its commercially successful Newport sandal – a hybrid open footwear that had its roots in sailing.

The rubber toe bumper of the Keen Revel IV EXP Polar Mid boot.

First seen on the Newport sandal,Keen’s protective toe-bumper is now a well-recognized feature.

The protective toe-bumper eventually turned into Keen’s unofficial trademark; today, most of its products use a variation of a toe-bumper as a styling marker.

Since 2005, Keen has marketed itself as a socially responsible brand that does things slightly differently. That includes owning a few of its factories, in contrast to the common practice of outsourcing. Keen also manufactures some of its shoes in the United States. The brand also seems to be involved in other social and ecological initiatives.

But that’s about the brand; what of its products? The recycled content and sustainable manufacturing aside, are the non-sandal products any good? More importantly, have they managed to break free of the ‘one product’ rut that many brands tend to get stuck in?

You know what we mean. More often than not, brands that grow rapidly based on a single silhouette suffer from the curse of not being able to break through into other segments.

For example, which product comes to mind when you think of Crocs, Converse, On Running, Altra, Hoka, and Vans?

See? It’s very hard to create product diversity once consumers are fixated on a single product or styling DNA from a brand. Very few brands have managed to break free of the single product curse. Notable exceptions would be sportswear giants like adidas, Reebok, and Nike.

Keen has tried very hard to build past the success of its Newport sandal, but it’s not there yet. Sure, the Keen Targhee assortment has had some success, but we doubt it poses a credible challenge to the likes of Columbia, Merrell, or North Face.

And in the rugged Chelsea boot market, Blundstones and Doc Martens reign supreme.

The Keen Revel IV EXP Polar Mid boot.

The Revel IV is a decent winter boot, but punches below its weight.

The Keen Revel IV boot is proof that the Portland-based brand has a long way to go before they can replicate the success of the Newport sandal in other product categories.

That being said, we have no idea how well Keen’s utility footwear business does. Keens produces and sells several technical boots with safety features like steel toes and composite shanks.

The sizing label of the Keen Revel IV EXP Polar Mid boot.

The Revel IV EXP Polar isn’t a bad winter boot; it’s just that there are similarly-priced or less expensive boots that do the same job that Revel is supposed to do, but better.

We don’t see any reason why the Keen Revel IV EXP should cost $200; competing boots like the Merrell Overlook 2 Mid and North Face Chillkat IV Mid are significantly cheaper and have similar or superior materials.


The heel view of the Keen Revel IV EXP Polar Mid boot.

The Keen Revel’s midsole offers supportive cushioning and insulation.

The Keen Revel IV EXP Polar Mid boot in the snow.

First, let’s talk about what the Revel’s sole does well. The firm, single-density EVA foam midsole is extremely stable and effective at insulating the foot from the frozen surface.

Of course, it’s not just the midsole that separates the foot from the ground.

The thermal insole of the Keen Revel IV EXP Polar Mid boot.

The Revel’s thermal insole has an insulated lining and a Polyurethane foam base.

The Polyurethane footbed of the Keen Revel IV EXP Polar Mid boot.

The thermal insole of the Keen Revel IV EXP Polar Mid boot.

Above the midsole is a removable thermal insole with a polyurethane base. The footbed is lined with what can assume is synthetic wool, and there’s a full rubber outsole underneath. Together, they form an effective barrier against the cold.

Though the Keen Revel IV’s claimed temperature rating is -32 Celcius (-25F), our test was done in higher temperatures of -19 C ( – 2.2 F). We’ll provide an update once we’ve had a chance to test the Revel in colder temperatures.

The outsole of the Keen Revel IV EXP Polar Mid boot in the snow.

The firm midsole and rubber outsole give the Revel dependable stability. There’s a molded shank in there as well, so the foam and rubber chassis feel planted over uneven terrain.

The ride comfort is decent, but not exceptional; the insole provides a helpful layer of underfoot softness.

The Polar Traction outsole of the Keen Revel IV EXP Polar Mid boot.

The ‘Polar Traction” outsole is new for the Revel IV.

The Revel IV has almost nothing in common with the Revel III, and that includes the outsole. New for the Revel IV is Keen’s ‘Polar Traction’ outsole – a rubber compound that’s similar to Vibram Arctic Ice grip.

And just like the Arctic Grip compound, the Polar Traction outsole is over-rated for real-life conditions. We wish brands would stop using this rubber compound and flat lug geometry. The Revel IV would have been better off with deeper and aggressively shaped lugs.

The outsole lugs of the Keen Revel IV EXP Polar Mid boot.

‘Ice gripping’ outsoles sound great in theory, but are practically ineffective in real-world conditions.

In theory, outsole tech like the Keen Polar Traction or Vibram Arctic Grip sounds great. The rough surface of the rubber lugs claims to offer dependable traction on ice.

The underlying logic is that the sandpaper-like texture will grip better on slippery surfaces.

The Polar traction outsole lugs of the Keen Revel IV EXP Polar Mid boot.

The lugs of such outsoles have a rough texture, and claim to offer ice-worthy traction.

At the time of writing this review, we’ve owned and tested several shoes that feature the Arctic grip outsole. We have tested the Saucony Peregrine ICE+ as well as the Kodiak Dundonald winter boot. We’re also testing the Merrell Thermo Overlook 2 that has an Arctic grip outsole.

These ‘Ice grip’ outsoles are nothing more than a marketing placebo. One of the things that’s not talked about often is the Vibram advertises the Arctic Grip outsole as suitable for ‘Wet Ice’.

A few years ago, they ran marketing campaigns that showed the outsole being tested on a slope made of wet ice.

The Polar traction outsole of the Keen Revel IV EXP Polar Mid boot.

Keen’s outsole is similar to the Vibram Arctic Ice, and just as useless on icy terrain.

However, a typical winter surface does not consist of ‘wet ice’. It’s either hard or black ice, slush, snow, or a combination of compacted snow and ice. And unlike the Vibram advertorial, there are no handrails on the road to prevent a slip and fall.

We detest outsole tech like the Polar Traction and Vibram Arctic Grip because they give the wearer a false sense of confidence.

Under these surface conditions, the Keen Polar Traction and Vibram Arctic Ice grip outsole do not offer a significant performance advantage over standard winter outsoles. Only spikes or cleats are effective on icy surfaces. If it’s just a thin layer of ice, get a set of shallow cleats like the Kahtoola Exospike. For icy treks, crampons are a non-negotiable.

One of the defining characteristics of an ‘ice grip’ outsole is a flat lug geometry. As a result, the lugs aren’t able to dig deep into the wintery surface for traction. For whatever it’s worth, we found the Keen’s Polar Traction outsole to have an inferior grip than Vibram Arctic grip.

The gaiter loop of the Keen Revel IV EXP Polar Mid boot.

Even though the upper has a gaiter loop, the low midsole clearance makes looping a gaiter strap challenging.

The low ground clearance of the Revel’s midsole makes the use of a gaiter challenging.

Since this is a mid-cut shoe with a low gusset position (more on that in our upper fit section), a gaiter becomes necessary at times. We haven’t tested the Revel IV in shallow streams; we hope to do that once the snow on the trails clears.

The low outsole ceiling of the Keen Revel IV EXP Polar Mid boot.

Even with a flat Gaiter strap, there’s not sufficient ground clearance under the midfoot.

This wasn’t an issue on the Revel III, nor is it a problem on comparable models like the Merrell Overlook. On both those shoes, the midfoot waist was high enough to let a gaiter strap or loop hug the outsole.

Also puzzling is the inclusion of shallow lugs as well as an absence of gaiter-friendly ridges. The broad midfoot doesn’t let the gaiter hug the outsole snugly.

The EVA midsole of the Keen Revel IV EXP Polar Mid boot.

The firm midsole provides a planted ride during hikes.

On hiking trails that do not involve ice, the Revel IV’s performance is satisfactory. The stiff midsole and hard outsole lugs feel planted on uneven terrain, and the firm ride provides ample protection from the rocks and roots.


The side view of the Keen Revel IV EXP Polar Mid boot.

The Revel IV Mid and high are differentiated by their amount of insulating fill. The Mid has 200 grams of Keen Warm.

The 200 gram Keen Warm insulation of the Keen Revel IV EXP Polar Mid boot.

Keen uses its proprietary insulation – the Keen Warm fill.

There are two versions of the Revel IV. We’re reviewing the EXP mid variant with a synthetic upper and 200 grams of insulating fill. The standard version has a leather upper with mostly molded lacing loops, but lacks the reflective lacing accents of the EXP boot. Both share an identical sole.

The ankle-high Revel IV variant has 400 grams of ‘Keen Warm’ insulation. Keen prefers to use its proprietary insulation tech made of recycled PET bottles instead of Thinsulate or Primaloft.

The difference in insulation between the mid and high boots is a standard practice in the outdoor gear industry. The mid version has half the insulating fill of the high version. Comparable examples would be the Merrell Thermo Overlook 2 Mid (200-gram fill) and high (400-gm fill), or the North Face Chillkat 400 and Chillkat IV that have different levels of fill.

The Keen Revel IV EXP Polar Mid boot in the snow.

As they say, dress for the weather. Excess insulation may cause condensation through sweating.

And why would anyone want less insulation? Isn’t more warmth better?

Not necessarily. It’s important to dress for the weather. Sure, if it’s too cold – say average daytime temps of – 25 C or colder – then a 400-gram fill is necessary to keep the feet warm.

However, wearing a 400-gram fill boot in – 10 C weather may result in condensation from sweat. Regardless of its ‘breathable’ claim, waterproof uppers are slow at letting the sweat evaporate. A long hike in shoe with a 400-gram insulation may soak the socks due to trapped moisture.

The Keen Warm insulation of the Keen Revel IV EXP Polar Mid boot.

Unlike competing fleece-lined boots, the Revel’s interior has a smooth texture.

So how does the Revel IV’s insulation perform on cold days? It’s ok. The Revel IV’s ‘Keen Warm’ fill did not feel as toasty as the Merrell Overlook 2, and we can think of a few reasons why.

To be clear – during minus 19 C ( – 2.2 F) days, the upper doesn’t let the cold in. However, there’s a sense of slight chill in the toe-box and a lack of the cozy feeling inside. We suspect that lower temperatures will heighten the sense of cold.

There’s a possibility that the Keen Warm simply isn’t as good as the industry standard of Primaloft and Thinsulate.

The interior toe-box of the Keen Revel IV EXP Polar Mid boot.

The lining lacks a fleece lining, so it doesn’t feel as warm as cozy as competing products.

However, we also think that the lining material also plays a role. The lining inside the Revel is Keen Dry – a waterproof membrane with a smooth texture. Unlike softer winter boot linings with a fleece-like feel, the Keen Dry bootie isn’t cozy.

It’s worth underscoring that the high version of the Revel IV has some fleece inside, but it’s limited to the upper heel collar area. The insides share an identical Keen Dry bootie. The Revel IV high’s tongue bellow also has a low position. The Revel IV also comes in a Chelsea boot form.

On the bright side, the compact lining makes the Revel IV true-to-size. That fit profile is uncommon in insulated winter boots that usually run a half size small.

The accommodating forefoot fit also allows thicker hiking socks to be worn without making the interiors overly tight.

Speaking of waterproofing, the Keen’s upper keeps the water out during rains – but with a caveat.

The low gusset of the Keen Revel IV EXP Polar Mid boot.

The position of the tongue bellow/gusset is fairly low.

The Keen Warm insulation of the Keen Revel IV EXP Polar Mid boot.

The low gusset position has a negative impact on waterproofing – especially when crossing shallow streams.

The tongue flap of the Keen Revel IV EXP Polar Mid boot.

This picture shows you how low the attachment point is. This design also leads to the tongue moving sideways.

The Revel has an unusually low gusset position, so the ‘water-line’ is much lower than other winter boots with a higher gusset attachment. For example, the identically-priced Merrell Thermo Overlook has a much higher gusset.

We’ll test the low gusset in a shallow water crossing and update this review with the result.

The metal lacing loops of the Keen Revel IV EXP Polar Mid boot.

The heel collar is stiff and needs a break in period.

The top view of the Keen Revel IV EXP Polar Mid boot.

The upper has a supportive and secure fit, but it could do with a higher level of interior comfort.

A break-in period is required for the heel collar; the folded edges of the upper are surprisingly stiff near the last lacing loop. Also, the tongue doesn’t stay in the center due to the low gusset.

One of the things that we love about Keen footwear is its toe bumper. It’s an extension of the rubber outsole, so it’s protective and durable.

The rubber heel of the Keen Revel IV EXP Polar Mid boot.

The ridges on the rubber heel wrap provide grip for snow-shoe straps.

The heel counter is overlaid with rubber with molded ridges. This non-slip ‘Shell back’ counter is protective, and also useful when mounting ice cleats or short Crampons for day hikes that doesn’t involve climbing.

There’s a gaiter loop on the forefoot, but then, the midsole design makes a secure wrap challenging.


Even though there are no deal breakers on the Keen Revel IV, the shoe feels like a work in progress. The outsole traction is sketchy on hard ice, and the low ground clearance makes it difficult to securely fasten a gaiter.

The tongue of the Keen Revel IV EXP Polar Mid boot.

The lack of a fleece lining affects the Revel’s insulation levels, as well as interior comfort.

The interiors have a true-to-size fit profile, and that’s good. However, the upper could do with a higher level of comfort. The heel collar is unnecessarily stiff, and the insulating lining lacks the plush, fleece-like feel of competing products.

The waterproof upper keeps the feet dry during the rains, but the low gusset position is a mystery.

We came across online feedback concerning the durability of the lacing loops, but we haven’t encountered any issues with our pair.


If you’re in the market for a mid-cut winter boot with 200 grams of insulation, we strongly recommend giving the Merrell Thermo Overlook 2 a try.

It’s less expensive the Keen Revel and has a higher level of fit and ride comfort. The fit is relatively shorter and narrower, and it’s slightly lighter. We found the Merrell Outlook 2 to have a noticeably high level of under-arch support when compared to other winter boots.

If you want to go even lighter, cheaper, and have the same amount of insulation, the Columbia Fairbanks Omniheat is an excellent winter boot. Though the upper is mostly mesh, the shoe is warm and waterproof.

The Fairbank’s $130 retail makes it exceptional value for money. It is one of the most comfortable winter hiking shoes below $150. If there’s a downside, it’s that the soft midsole isn’t as protective. The outsole depth is shallow and lack the bite of boots that feature aggressive lugs. Therefore, it’s best used as a versatile urban winter boot.

Though the North Face Chillkat IV also compares, we suggest sticking to the Merrell Overlook or Columbia Fairbanks instead.

As a side note, the Chillkat 400 with the higher cut and more insulation is an excellent boot. But it doesn’t compare directly with the Revel IV Mid; it’s in a different segment that comprises of high ankle boots with 400 grams of insulation.

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